TOMASO PANTERA GT-5 IS A BEAUTY. 9,4 LITRE HEMI ENGINE MAKES
IT A THRILL TO DRIVE.
WELCOME TO MY PANTERA and GUITAR
The idea behind this site is to share technical information
and ideas with other people having the same interest in sportscars and
guitars. The fact that the car is a Pantera is of little interest from
that standpoint. Since I am an old man, so is this side of an old-fashioned
Right now ( 2013 Juli) the car is having a new engine,
all aluminium. This is shaving of some weight and gives a few extra
cubic inches, JUST what the car needs. A sportscar can NOT weight to
much and can NOT suffer from to small an engine. The whole idea with
a sportscar is that it is FAST and a challenge to drive. The adrenaline
gauge should raise and make you aware that you are not sitting in an
No turbo, no compressor,
no nitro bottle. Just a normal, naturally breathing engine. Sequential
injection, ignition and dual COP coils.
Myself 2009. At the
time the engine had the older valve cover and analog ignition.
CGH is lowered to 390mm and the front
to rear weight is 38-62%
Top, A picture from Mantorp Park
race track. A picture from Mantorp Park race track. Shot by Anders
Odeholm, a top Swedish photographer. Pic
is from Mantorp Race track.
I really like unique buildings,
so I am driving around once in a while to shoot a few nice images.
Top and left is the Wik castle and lower image is the stable at
the Taxinge castle. All in the Stockholm neighbour hood.
A chassis engineering book that
show the build up of the Speedlab Corvette race car.
This is a book about how to build a racing car. I describe the
process step by step, using the build up of a racing Corvette
as a working example. For those who like Corvettes this might
be of special interest. I am using a building theory of my own
called the "Zerocar" philosophy. The Zerocar is a car
that has practically no suspension angle's, ground level roll
centre and no anti's. What makes a racing car faster than a production
car around the track is that it is optimized to do what it is
set to do. A daily transporter must be able to do a number of
things and be able to drive in sun, rain and snow. The race car
will become a nightmare in snow. This means that the daily driver
is having a number of features that has no place on a race car,
and will therefore not be very good to use as a platform when
explaining the building process. The Zerocar is a "clean"
car where we only need to add what is needed to make it suit our
application, no less, no more.
The book include...
Aerodynamics, tires and wheels, braking systems, dry sump systems
and effective oilpan design, cooling systems, exhaust systems.
Calculations, math, tires, wheel alignment, suspension geometry,
springs, swaybars, a quite large section about shock absorbers,
engine management systems and injectors-sensors. Everything very
much down to earth, to make it possible for a small team to build
a fast car.
The book is in English. A4 format, 315 sides and 457 images.
Interested? Drop me a mail with your name and adress to firstname.lastname@example.org
Payment should be done in advance using
PayPal, to the e-mail adress email@example.com
€108. $156. £98. Including shipping.
Dont forget to mail your name and adress!
Behandlar väghållning i allmänhet. A-armssystem
o fjädringsberä kningar, däck och stötdämpare.
Beräkningar för bromssystem och grundläggande broms-fysik
är ingredienser i boken. Även lite aerodynamik och hur
under-sidan av bilen med splitter samt en vinge fungerar, men även
lite motor-teknik som kylsystem, avgas o insug-ningssystem och torrsusumpsmörjning
finns med. Bra bok för den som redan har en färdig bil
och vill jobba med instälnningar o service. 130 sidor. 400:-
Banbilsboken. Boken behandlar
hur man bygger en banbil från grunden. Jeg har en egen filosofi
som jag kallar "Nollbillen" som är ett pedagogiskt
sätt att belysa hur man går rätt tillväga.
Jag visar hur man börjar från ett blankt papper, designar
chassiet och hjulupphängningar. Boken innehåller dessutom
mycket av väghållningsboken samt hur stötdämpare
fungerar, avgasrör, insugningsrör, kylsystem, torrsumpskon-struktion,
bromssystem, aerodynamik samt insprutningssystem. Även sådant
som kulleder, materialval, profiler, pushrods, beräkning
av lastväxlingar, roll-axellutning, samt ingående anlys
av "anti" funktioner och rollcen-trum. Passar den som
vill gå steget längre och bygga eller bygga om sin
bil. 350 sidor och 450 bilder. 900:- inkl frakt.
A few words about my guitars.
A new design
of my guitars, the "Hemi Pantera guitar". Coloured
as my Hemipanter car, Destributed by Tip Top musik,
My own bass model. The same shape and body size as the guitar combined
with the Gibson length scale. The bridge is of solid brass and apart
from the guitar this bass has some fine tuning adjustment screws, seen
on the lower image. The picups is hidden and mounted from the back side
of the bass, and the treble picup has an pre amp built in. Each pikcup
has its own channel and two amplifiers to be used, preferably using
an exponential horn for bass and some kind of midrange-tweeter speakers
for the treble pikcup. The top is Rio Jakaranda.
The guitar is curly maple top. I use the same bridge of solid brass.
The idea is to have enough mass to not kill the oscillation energy of
the strings, resulting in longer notes. Another advantage is that no
rattling sounds from loose parts in the string holder is present. Fine
tuning is made by filing the bridge for the type of strings to be used.
Original cream PAF humbucker. These are very special sounding picups
that will hardley be duplicated.
A spectra analysis of the magnets made by the Ericsson FOA laboratory
tells that the old type alloy is not uniform due to old tecniques and
therefore discontinued prior to more stable types that better meets
the specification. However, the old type magnet gives the picup a unik
sound that due to uneven alloy is also different between picups. And
may even be different side to side of a single picup All this appart
from the fact that Gibson also used different strength magnets. I have
been keeping the very best souning PAF:s during the 60:s, and do now
have those mounted on this guitar. One black and one cream. Picups that
has to be listened to before speaking "copy" PAF sounds".
It is specially the attack dynamic properties of the picup that is amazing.
Another issue witht those picups is that they should be magnetizised
as a whole and then not to be dissassambeled since these magnet need
the loading of the iron in the construction to stay the same field power.
There is a balance act going on concerning the unique PAF sound. We
have a magnetic field, a quatitie of pole iron, a number of bobin windings.
It might appear nice to rise the number of windings to rise the voltage
output, or use the strongest magnets, but the construction will become
"overloaded" and we will loose the sensivity of dynamics.
Led Zepelin 1969 using my speaker
Photo from an early Cream video, Eric Clapton playing on
my guitar. Special design head, in an attempt to put my own personality
on the guitar. The body is hollow semi-acoustic.
The expert guitar man may notice that
the bridge is not Fender stuff. "Zebra" maple body.
The Abba guitar.
There have been rumors about who made this guitar,
as well as the exact design. Since it is missing so are the rumors unchallenged,
until it resurfaces. Since ABBA museum and some coverband was interested
in having the guitar in their show, I decided to produce two new specimens.
However, I would thereby put an end to rumors about who made the guitar.
Goran Malmberg 3 juli 2011.
ABBA with the star shaped
guitar at the
Eurovision song contest.
Reconstruction of the guitar.
This is a You Tube release of the old Ghost
Riders in the Sky. It show the special sound of this bass even equipped
with tremolo arm. http://www.youtube.com/watch?v=72X0q2EMxbA
"Shadow" a song I composed on Juni 2013 and recorded a day
later and filmed at the same night. It is about the shadows so it is
One of my newly composed piece of music and
related video called "Rain". A gentle song played on my base
as usual. A great thanks to the Po Alm for his Almeko which is a big piece
of the puzzle for me to get up the tremendous sound in the base.http://www.youtube.com/watch?v=z4xPUgPjRGk
hemipanter video. I passed the Drottningholm Palace and gilded
the royal wedding ceremony. Salut with guns is not enough, what is needed
is a mighty engine noise. (They dont use Viggen aircraft these days,
which would otherwise fill the requirement).
I did finally finished the work, after a year hiatus. I
need to get in to "guitar mode" in order to to do this kind
of job, since there is no room for failure with details.
Why a Pantera? I dont care very much for what make the
car is, but the Pantera do have a few things going for it. It
is a nice looking car. Technically it has an all steel monocoque.
It is said to be torsionally weak, but this is mostly due to rust
and age. It provides a roomy engine bay accepting almost any engine.
Maybe not a V-10 engine, as length is one of the engine bays few
limitations. Suspension is the same as on most Italian sportscars,
so handling is very much a question of setting the car up properly.
Pantera is missing adjustabiliy of suspension. If adjusting the
sway bar, one finds oneself forced to change to another rate bar.
On the other hand it has a very reliable and clean and neat installation.
I do like simplicity. The car should have NO more parts than absolutely
necessary. I this context, the Pantera is well suited as a street
car. Surprisingly , perhaps , many items that makes race cars
fast actually makes a streetcar slower. (Se spring settings)
Why a Hemi? It is a legendary engine. In fact, it is the
world's fastest engine. It holds the top fuel record with 4,44
sec and 543km/hr. It holds the ss/aa (stock) 1/4 mile record with
a Hemi Baracuda
at 8,64 sec in the . In prostock it holds the trap speed record
at 327 km/hr. And last but not least, salt flat piston-engine
wheel-driven car speed record, of 432 mph or 692km/hr. The Hemi
is like having some racing history in the car.
Motor-horsepower philosophy. Some of you may wonder
about this elephant motor in a sports car. Sports cars are supposed
have small 15000-rpm motors. Well, I am of a somewhat different
opinion . The only number of interest is horsepower
. Horsepower is related to how much air and fuel the engine can
burn, per time. Which in turn is related to how many cubic inches
of swept volume the piston produce, per time. Presumed we are
talking about engines with an efficiency of near 100%, cubic inches
is about the only way to more power, since rpm is limited. More
cubic inches per time can be had by.....
1) Larger piston area.
2) Higher piston speed. Which in turn is related to...... A)
More rpm....... B) More stroke.
3) Supercharging or Nos. This is not the area of subject here.
Racing cars has limitations for engine size. Therfore, they userpm, to produce more cubic inches, per time.
On the street we do not suffer racing regulations.. And as this
is a pushrod engine, I therefore limited the rpm to a rather relaxed
7000 for the street. I ´d rather use stroke to create mass
flow. Some sports car gurus claim a long stroke big incher will
suffer from dull throttle response. In my opinion this is not
necessaraly true, as pistons acceleration at its mean piston speed
(mps), has got nothing or little to do with stroke.
However, an over-square engine do not have the same head area
to give room for biggest possible valve area in relation to cui.
But the Hemi can take a lot stroke without running in to that
sort of problems.
What about torque??? Torque is a good indication of efficiency
, mcp , mean combustion pressure . How well the combination of
induction, head porting, combustion chamber, exhaust headers,
camshaft and engine geometry, all work together. Here is (my own)
rule of the thumb. 0,1Nm per cc engine size represent close to
100% volumetric efficiency. In my case (526 cui = 8626 cm2), x
0,1 Nm = 862 Nm = 633 foot-pound. So, to be accepted as an OK
engine build up, my engine has to be able to deliver 633 foot-pound
Ferrari F-50 GT deliver 520 Nm from 4700 cc. 520/4700
= 0,11. Which equals 0,10% boast without a charger.
commonly misconstrued as power at low rpm. Please let go of this
misconception! It is not. To move a car faster, at low (as well
as high) rpm, the engine must produce more horsepower.
If a 3000-pound car should do the quarter in 10 seconds , we have
to have 600 horsepower at the rear wheels. It is mathematically
impossible to tell how many foot-pounds of torque that is needed
to do the work. Of course, we can say, xxx fp of torque at yyy
rpm , but then we are talking horsepower again. ( hp = torque
x rpm ) , hence, high rpm torque produces the best HP. In other
words, I like my motor to produce torque at high rpm. In fact,
the best torque producers are very high rpm motors. Those take
real advantage of tuned intake and exhaust system, ported heads
etc. So, when it comes to specify a quantity of work, the correct
way of referring to it is horsepower. Even at low rpm.......
A drawback with a big incher is that the engine get physically
big and heavy. By the use of aluminium heads etc, my car weights
in at 2600 pounds, this is lighter than the original Pantera with
a 351 Cleveland stopping the scale at 3100-3200 pounds.
Engine. The old HEMI
is conducted by a modern engine management system by Haltech
E6-K. The motor is based on the new cast iron HEMI block.
At first I used a aluminium block, but this was of a fueler steel
liner type that did not work well for a gasoline engine. At a
cost of 60 pound I selected the more reliable iron block. After
all, the block sits very low in the chassis and may also help
acceleration a bit due to its closeness to the rear wheels. 7-inch
billet alu rods and piston with "ring land" pin. Even
with this long rod the ratio is only 1,59:1. Alu rods have reputation
not to last very long. According to the manufacturer the rods
will live for 40000 miles. My engine is apart every 4000 miles.
And by 40000 miles, every vital part has been replaced anyway.
A 4,40 stroke billet crank necessitates grinding out the block
and remove the original provision for oil pickup. But as I use
the KB pump, oil pickup hoses runs outside the engine.
The heads is what separates a Hemi from other engines. It has
been a lot discussion about Hemi vs the wedge design combustion
chamber. As with everything, there is no optimum chamber design.
It all depends on what we want the engine to do. Hemis have a
170 cc combustion chamber, great for top fuelers but not for a
gasoline 426 engine, as we end up with 6,5:1 cr ratio with a flat
top piston. Or, one must use a big dome that creates an orange-shell-shape
combustion chamber with deep valve notches, shrouding
the valves . But with the additional 100, or better still
200 inches, we can make the Hemi head shine. With a small circular
quench-dome we have a street able 10,5:1 cr ratio, and a nice
burning chamber. With a 15:1 cr pro stock racing engine, limited
to 500 cui, we are back in to troubble again. This is the reason
the new prostock Hemi use quench areas in the heads.
The installation, of the Hemi in the Pantera required
a few things to be fabricated. An adapter plate to fit the gearbox
bell housing to the engine. Header fabrication, and a 3-inch exhaust
system. Reworking of a Ford aluminium flywheel to suite the Hemi
crankshaft. Machine the Hemiblock to allow for a right hand side
starter motor. Adapters to suit Pantera motor mount. Machine the
heads for water outlets. Plugging of the block water outlet and
machine the block for a short style Chevy water pump. Fabrication
of a new oil pan. These are the main items , then it is just some
belt pulleys, alternator brackets etc, like always in a build
Is a story for itself in a wet and this very close to ground
installation? This is my 4;Th pan. And now it seems to function
properly. Of course, I could have used a dry system, as
in my earlier Panteras, but the KB pump made a clean installation
without to much hoses belts etc. And a stimulating challenges
to make a wet pan to carry over 1g in any direction. A good
design oil pan is important since it allows the use of smaller
quantities of oil, without the risk of oil starvation. I
want the engine to warm up quickly, which is not possible
if too much oil is used. This pan is designed to hold 6
quart of oil, which is enough to prevent from any possibility
to suck air. However, if I happen to be in a situation of
a long distance driving, where there is a risk of the engine
consuming oil, the pan can handle an extra 2-quarter. And
the pan is safe down to 4 quart.
Very long bolts was welded together.
I made some trapdoors to control the oil.
The oil pan sealing surface to the engine
would most likely get uneven when welding. One way to
get it straight is to tin putty and sand it .
The windage tray with separating walls
I am very pleased with this oiling system.
A wet system allways has its limitations but with this
in mind I could not expect it to be better. In any case,
it is very much compact design.
Engine appear to run slightly cooler which
indicates less oil splashing around the crank.
This drawing show my former drysump system
design. Pump is very low mounted on a oilpan bracket.A
number of scrapers over the full lenght of the crankchaft.
As I have no dyno , I did all the injection programming, driving
on the road . To make injection timing a little more visible,
I transferred the numbers to excel format , to be able to look
at everything in 3-d form. I also used a lambda sond for analysis.
After some 30 years of all types of carburettor tuning, it is
quite interesting to see a hard copy of all injection numbers.
Some were very surprising. Especially the Webers have given
me a rather solid background from which to view this, and I have
developed a feel for how the engine is running. Being musically
inclined & a guitar builder is also a great help , as I know
the RPM by the note of the engine. Thus making lap top tuning
while driving more easy. Equally important with ECU management
is ignition timing , which could be set to any chosen degree over
the engines entire rpm band. It even allows the engine to run
cooler as the timing could be optimised to give crank energy instead
of heat. Seen over the whole season of 3000 miles, the engine
has appeared to consume some 15% less fuel compared to the carb
seasons. The lowest consumption at steady 60 mph, was 16 mpg.
The season average is 14 mpg, compared to 12 on carbs. No city
driving is represented in those numbers. The engine runs better
in traffic, start ups and idles more reliably in coold weather.
As for power output, the engine shows better performance over
the entire prm spectrum .
Intake manifold. I used a Weiand tunnel ram, as
a base to fabricate an intake manifold. Tunnel rams are well known
, not to work very well as a street manifold. But this is more
of a carb problem. The big plenum of a tunnel-ram is hard to handle
for a carb. In a port fuel injection set up, it turns out pretty
great. Here are som reasons...
1, 426 tunnel-ram channel areas is design for high revs.
But with 572 cui 3,9 square inch area will put the torque peak
down to just over 5000 rpm.
2, The channel is longer than the dual plane which gives
better low end.
3, Very straight and thereby easy ported channels.
4, There are no "accelerator pump filling the plenum"
problem, since the injectors are close to the heads. For the same
reason we do not suffer from weak venturi booster signal, commonly
associated with tunnel ram manifolds (using carbs)
Fuel rails. I fabricated fuel rails from 1x1, 5 inch aluminium
bar. Fuel line is 3/4" diameter. Both rails is running in
parallel to the pressure regulator and return line, which is good
for delivering the same fuel pressure to all injectors.
Trottle body. Is of my ovn fabrication, making the tunnelram
bottom to an independent runner manifold.
Coil on plug configuration, using 8 VW coils.
Headers are 31 x 2,11 inches, giving the engine a peak at 6000
rpm. I have my own (guitar tuning) trick of tuning the exhaust
primary pipes. By listening to the note of the pipe, it is possible
to tune all primary (and secondary pipes respectively) to the
same frequency even though this might result , due to bends and
such , in some discrepancy in actual physical length. Think of
it as an organ pipe. Sing a note in the pipe listening for the
resonance to tune in. The frequency is a function of air volume
and pipe length. Staggered pipes they may be , but we´ve
got the resonance length spot on!. And frequencies is what the
engine senses. A fraction of an inch is easily detected in the
variance of note. End pipes are 3 inches x 25. To quiet the car
I use a large silencer, pictured later in this site.
Another interesting side effect of "guitartuning" the
exhaust is that it provides great music! Especially with the very
short system of the Pantera which responds to almost any change
in pipe design. And as no surprise, good note and performance
are more often than not very , closely related.
180 degree headers, 90-degree headers, tri-Y headers.
Well, I use regular headers. In my earlier car I have been using
all type of headers. The 180 and even more so the 90 headers give
a V-8 the same sound as a 180-degree crankshaft or V-12. They
also look impressive. They do have some tuning advantage and a
few more horsepower. But, this design almost allways comes out
with too long primarys. Making them suitable for lower rpm engines.
On the other hand, regular headers will be to short in the aviable
Pantera header-space. With the wide Hemi motor 180;s are an almost
impossible fit in the Pantera. The Hemi has a special sound to
begin with, that are greatley backed up by regular design headers.
After a lot pipe tuning I am proud to say that the car has received
a lot attention for having a great heavy sound.
My 302 Boss Trans Am engines built
by Falconer Dunn. Fords highest reving engine ever. 9000 rpm
in the Ford catalog. Here equipped with 180 degree headers.
The end pipes is close together, important for a great sound.
This particular engine produced 427 hp. Four IDA Webers and
dry sump oiling.
90 degree headers on a 500
Ford big block. I used this motor in the late1980;s. This
system was very quite, and nice sounding. The silencer had
a 4 inch core diameter
My first big block Ford motor for
the Pantera, 1985. This is a 385 series 460 stroked to 500
cui. Using Ford motorsport aluminium headds and intake for
dominator carb. Dry sump system and electrical water pump.
Also, 90 degree header system.
This is an aluminium tool
for turning the butterfly to oval shape. Butterfly is
sandwiched between the two aluminium clamping tool parts
with two screws, using the two holes to be mounted to
the trottle shaft.
This way the butterfly will
stop in closed possition and can not turn any futher.They
are made from chrome molley steel in order not to bend.
Axle are offset for the butterfly not to open itself
by vacuum.The diameter is 2,41".
Air filter is a must. It must not block the
rear mirror sight and be very light and filter
the air. It must also supply the engine with
cool air.The Lexan holds together by a thin
aluminium frame makes for a weight of just over
Weiand tunnelram bottom but without
the plenum and I use two trottle body in its place.Stacks
that is shaped to make a good air entry in to the runners
and also making the runner a little longer, now 13,38".
Injector test bench.
The intake runner of my engine, showing the location
of the injector.
Bosch Ev 14 injector i delar.
Bosch 040 940 cc injector has good atomization.
To the left at 2ms duty and above at constant duty.
Compared to RC injector 880 cc, sort of shower
style beam, not to great.
If we want soething really nice! This is the
Volvo Bosch 214cc injector. Here at 66 psi fuel pressure.
RC inj266 cc injector of similar small size,
Not to bad but still not as good as the much larger 040.
Lighter suspension bolts.
New composite firewall door. Very
light 4,4p flat with insulation and bolts.
Dec 2008! A new clutch again.
The two disc racing clutch was a bit hard to use on the street.
A very simple balance machine! The
brown part in front of the flywheel is hanging down in a bearing
and can move sideways then. It works great for both static
and dynamic balancing.
Header fabrications. I used a wooden
dummy frame of the car when I built the exhaust system. 1995.
Making a new carbon fiber hood.
E85 fuel is not building any soot inside the
combustion chamber. Piston remain as new.
.This is a primer oiling container, very much
the same as an accusump, but smaller.
is important to have a both quite and efficent exhaust sytem.
One thing that is hard to bypass is that such system demand
i large volume silencer. Luckily the Pantera have space for
The main silencer is a perforated tube. Inside baffle is
The outside of the silencer is cowerd with fibre glass.
The outside is from sheet aluminium, rolled
to shape using a round tubing and using my own feet and weight,
on two of my boat seats.
And finally the aluminium cower is in place.Tightened
in place by two large hose clammers.
The muffler section of the end pipes. A number
od holes are drilled.
2 end pipes each side as the original look.The
end pipes are slided over the final muffler tubing.
Balsa wood bumpers! Since lighting
is needed, I produced a "LED lamp" panel that provides
50 lumens.All external surfaces are covered with gauze from
care, glued with wood glue. A thin layer of light trowel smooths
the fabric pattern, but only on the outside. It weighs 215
grams, complete with bolts and everything.
scoop for the Pantera!
The Pantera suffer
from under the hood hot air. So, an air scoop is to be fitted.
Not really a dream of design, but quite effective.
The Pantera hand brake is not the very best.
This does not really make it brake better but it sure include
less komponets and is ligther. By making it lower the lever
arm down to under the car is getting shorter thereby making
the extra factory arm unnessesary. On the underside of the
car there is from the factory a lever arm that makes life
hard if trying to remove the oilpan.
Gear box linkage.
I used a standard roller timing drive
from Comp Cam:s, and machined all surfaces. An aluminium bearing
centre was fabricated.
Here in its possition with the cam
bolts in place. There is an identical bearing on the other
side of the gear drive.
On the inside of the cam cower there
is a bearing thrust plate mounted. I am using zero end play.The
layer consists of 3 parts, two outer steel shims and roller
tray in the middle.
Theories. The Pantera is a neither a ground- nor wing-effect
car. Well, the GT-5 does sport a big cosmetic rear wing. Over
the rear hood.... probably creating "wing to hood" down
force instead of "wing to ground" down force. There
is a common misconception that a good car should have a 50-50
% weight distribution. The thinking behind this is seems to be
that the car should have equal loads on all wheels. However, static
weight distribution is valid only in the parking lot............
where no tire grip is necessary.
What is important is how the dynamic weight distribution
affects the car. This depends on the whole car as a concept. Extra
friction is created by the use of a large and soft rubber area.
And it is desirable to under all driving conditions keeping the
weight distribution as even as possible over this rubber area,
(except during acceleration). Under braking and while cornering
all four wheels are used. This calls for a low centre of gravity,
in order to to minimize weight transfer. Under acceleration only
two wheels are used to move the car. Now the entire weight needs
to be at the rear wheels. What is good in one situation is easily
disastrous in another. So, I work with what I percieve to be a
reasonable static centre of gravity . Which in the case of the
Pantera (when over 500 hp) is 60-65% rear bias, backed up by the
same proportion tire area. This gives me 55% front load under
1g of braking and thereby a good help from the rear tires. At
1g of acceleration I got 70% rear tire load, to secure a good
grip. Then using sway bars, springs, shocks and suspension geometry
to handle the weight transfer in the best possible way under different
The fastest way is a straight line.Any movement up-down-left
- right should be avoided.If the road turns, the driver
should straighten out the travel line.When
the road has bumps , as small part of the car weight as possible,
should move up and down. Here the suspensionwill
straighten out the travel line. When the car corners
at its limit, there is scanty litle room for hefty driver actions
or hard suspension settings. Emerson Fittipaldi once had a driver's
school in England. The school car had a horizontal parabolic cup
with a tennis ball in it, mounted on the front hood. The idea
of the exercise was that the car should be driven around the track
gently enough to maintain the ball in the cup. This teaches one
that anything to harsh and heavy will make you loose the ball,
or what it symbolizes, the grip at higher speeds.
The monocoque chassis, of the Pantera is made of 0,036"
steel , and weighs in at just about 500 pounds, which is not very
heavy by any stadards. I like this type of construction where
every part of the car adds to the structural strength. Nowadays
most racing cars use tub-monocoques out of carbon fibre, where
even the engine is involved as a structural member . Great stuff
and a similar technique. The steel body of the Pantera does not
tolerate rust as this completeley obliterates torsionall stability.
In a 30 year old car rust is a problem. No two ways about it!
I have torsion tested a number of Pantera chassis. Rusted as well
as rebuilt. A rebuilt (or new) chassis is stiff enough for hard
street use. Rusted are NEVER!. I tested a nice looking chassis
that could only hold 700 foot pound/degree!!! On this car almost
all of the profiled middle rocker pantel section was rusted out.
Torsional stability. 700 fp rust figures, has given Pantera
a bad stiffness reputaion. Especially since the car not seldom
looks quite sound from the outside. Thus making it easy to put
it down to bad engineering . People then start to bolt on all
kinds of stiffening devices in place of fixing the rust. But even
a sound Pantera could use a few more foot pounds of stiffness.
When twisting the chassis it is easily seen where flex occurs.
Stiffening of those areas by triangulation, is not always easily
accomplished. One would prefer be able to get in and out the car,
have a motor in the engine bay, etc. This very often result in
tubes positioned where there is space left. Bent tubes, and tube
joints where the tube intersection does not line up. Tube reinforcements
also create new stress concentrations and weak points elsewhere.
My idea has been to reinforce the chassis
in a monocoqueish manner . As said, the whole chassis support
torsional stability. Certain areas support more load than
others. These areas are "profiled" by the same
0,036" sheet metal. Often with a diagonal middle wall,
in a three wall "tube" like profile. To make a
supporting profile made from 0,036" steel strong, one
must see to that the metal recieve straight loads. In other
words, there should be no waves in the sheet metal when
welded in place. Something which takes an experienced chassis
tecnichan to do . The Gt-5 skirt. (rocker panel) was originally
made in fibreglass, thus only creating a good looks. I made
them in steel, integrated in the chassis with a large cross
sectional area. These type of actions stiffen the chassis
with neglible addition in weight , which is the very idea
with a monocoque. I do have a roll cage, but this is strictly
for driver protection. However, I have been driving this
car for 16 years with racing rubber. And 8 years with the
Hemi. And , to date , without any type of flex related problems.
Floor reinforcement and steel rocker
panels. All floor profiles is made on the inside of the car
to make a flat under-outside.
Chassis frame structure.
This is a wooden chassis model of
the Pantera "frame" structure. I made this
to sort out what happens to the chassis under stress.
The model is then dressed up with an outer shell,
simulating the outer body panels. The model is twisted,
and stressed in all kinds of ways. As a structure
only and with outer panels, roof and floor in place.
Different types of bracing are applied to see where
it does some good. There are two areas of concern,
1. The rear section, 2. The coupe. Needless to say,
the structure alone is no stronger than a playing
I have been driving th Pantera with different
torsional stifness numbers and with stock setup coilovers
there is hard to separate 5000 to 15000 fp/dgr from each
But with racing tires and 3 Hz springs
and matching dampers, tuning becomes more exact. What really
loads the the chassis is the dampers, so schock settings
is what is the moost noticeable.
Two electrical plastic tubes is used for measuring tool.
Inside the two sliding pipes is a spring that keeps the
expanding tool in place.All measurments is performed at
a torsional load of 3000 foot pound.It is importanr to understand
that in order to stiffen the car we MUST recognice areas
of movement. If there is no movements, there is no gain
by placing a bar in..Also, is is the torsional twisting
motion that is to be stopped. Otherdirection of flex dosent
really hurt cornering performance. But it might save the
car from uggly paint crackings. What is said here does not
concern safety and impact situations. A cage is the way
to go then.
Diagonal engine bay lower part.+0,04
Diagonal engine bay. -0,125",
+0,0197", 0,5mm. To frame.
Engine bay horisontal. 0,00 "
Rocker panel to roof-window pillar.
Coupe diagonal. 0,018",
Right door+0,02" 0,5mm
Left door -0,02", 0,5mm
Hemipanter has a torsional stiffness of 15500
As for references.
Lamborghini Countach 1900 fp/degree. Ferrari 360 spider 6250 fp/degree.
Viper gts has a "tube space frame" and 9000 fp/degree.
Viper gts-R (Le Mans 24 hr) is reinforced to 13600 fp/degree.
also uses a high strength tube frame supported
with honeycomb carbon fibre to 15000 fp/degree. It clearly shows
that the Ferrari has no roof. Here we have cars with cromolly
tube frames, carbon fibre, etc. Exotic material, loudly advertised
as great stuff that makes those sport scars outstanding. Let me
mention that the new SAAB
9-3 Sport Sedan, steel monocoque has a torsional stability of
16000 fp/degree. Showing that good engineering is
more important than the use of fancy materials. Embarrassing for
the SUPER cars? The Panoz
racing car tub carbonfibre monocoque has a stiffness of
45000 fp /degree, but due to the front motor installation the
axle to axle ratio is 30000 fp/d, at a weight of 110 pound. A
street car that uses a tub monocoque is Koenigsegg
. Also made of carbon fibre. This tub is said to have strength
of 20500 fp/degree. As this, like the Panoz, is a tub number,
the axle to axle ratio should be less. With the same reduction
as the Panoz, we should land at 13600 fp/degree. This show that
a monocoque is the way to go, even if made in sheet metal. The
reason for using steel tube frames is the ease of production in
a small numbers. A steel monocoque takes a tremendous investment
in tools and engineering.
A car wing works in the same manner as an aircraft wing, but
upside down. The lifting "vacuum side" of the wing is
now the underside. The wing works the best when close to the road
and in an undisturbed air stream. Like the front wing of a formula
1 car, that create a high vacuum against the road. The Pantera
rear wing is mounted over the rear hood. Creating vacuum between
wing and the rear hood is of no use. It is like lifting oneself
in the hair.
The look of a wing is spectacular. Widley discussed as beeing
a design only item. Aerodynamic is a question beyond personal
opinion. A wing could be used to create downforce. No matter what
people think of its design. If it makes the car brake and turn
better, I will use it. And if the function is OK, I will put some
effort to make it look good.
On a ground effect car one might use a wing close to
the rear body of the car, to make it work in conjunction with
the underside of the car. The Pantera has no rear under side.
Instead of creating down force, the car "vacum cleans"
the road. Making it nesseary to clean up the engine compartment
after every ride.
For a rear wing the only free air stream is quite high
. It should also be mounted way back. Wing-(s) should also be
positioned so that the centre of down force is located aft of
the centre of weight gravity. This self stablices the car at high
speed in the same manner as an arrow with feathers in the rear.
The wing could and must be made light because
it is the highest point of the car. And has a great lever, like
a trailer at the back of the car. And it is possible to make it
light beacuse the loads carried by the wing is newer very high.
At the most 0,8 pound/square inch. Most likely around 0,5. Down
force changes by the square of the speed. If you can push the
car by the wing it is probably strong enough.
Does the car need wings?Or better put, aerodynamic devices.
Yes, if we like the car to be fast in corners, there is no alternative.
Or else, we are stuck in stone-age corner speeds. Without down
force devices we could newer corner much more than 1-G (street
tires). Correctly engineered air devices also improve straight-line
stability. Even at regular road speed of 60 mph we should theoretically
be able to raise cornering G-s by 10-15 %. Downforce
racecars. Mulsannescorner databas, great racecar info.
The original location of the rear wing.
If one want it for looks only, this is OK. It stays within
the size of the car itself. Check the wing location of a Trans
New test location of the rear
wing. In fact, now it begins to make some good. The
angle of attack is a shot in the dark, and gives 150 pounds
of downforce at 94 mph. Adding 8,5% tracktion at the rear
wheels. From here I will go on testing.
Lola, good ecample of aerodynamics.
Rear wing aft of the car!
My own design
front hood. All air passing through radiator is
coming out here. I made this for my first Pantera. Altrouhgt
this on is used on Bjorn Carapis 219 mph car.He did not experience
any speed front end lift.
This is the cooling air outlet
director. A single powerful fan from Audi fabricated by Siemens,
The new hood was 4,7 kg or 10,34 pounds. The original was
17 kg or 37,40 pounds. Then we got a few things more spared
on the car weighting 1,7kg or 3,96 pounds. For a sum of
Fabricating a new front hood in
fibreglass.Sandwished with bonocell layer.
The undrside is almost flat. There is
an area where the jacking stand is placed that is still open.
(I has to hawe wheels). And far back under the engine. The
first wersion splitter pulled 50mm of water in the middle
of the car, at 75 mph.Underside flat surface is 36000 cm2.
We will see what this splitter will do.
More horsepower in the car it is often said that one must follow
up with more brakes. I agree, but with a few corrections. Street
speed depend more on the driver (if he like to keep the licence
or not), than on engine output. If a 3000-pound car is to be stopped
from 100 mph, we need brakes for that purpose. Not for how fast
the car can reach 100 mph. On the racetrack more HP always result
in a rise of the average speed, as the car always is used to its
limit. Race car drivers knows exactly where to go off the throttle
and start braking. This is not the case on the street. Road, sports
car drivers must use a safety margin. This margin makes for more
cooling time. So, I will not use bigger discs than just what is
needed to prevent from overheating. Unnecessary disc weight reduces
cornering power on rough surface road.
I will use the very best low temperature working pads. And no
bigger or heavier calliper-pads than needed for even pad wear.
The master cylinder system should be balanced for the callipers
used. Of course, one can make a few laps at the track. And some
very fast laps to, before it is time to stop and cool the discs
With this in mind I designed the
brake components to make a light combination. Therefore, although
weaker than iron, aluminium callipers is used. Aluminium has
a flex module of 10 and steel 30 million. I use one piece
and closed back type calipers. I fabricated this one-piece
aluminium hub (image) to mount wheels, discs and front wheel
bearings. Discs are Lockheed, 20 mm ventilated. Until now
I had no experience of overheating (on public roads). It may
also be possible to use solid discs (only for the streets)
as they offer slightley better stopping performance because
of better clamping support, and are less prone to cracking.
Great feature for one big high speed stop to zero. An often
overlooked factor is to use the right type pads. The right
pads makes the original Pantera Girling calipers more than
enough for any street Pantera. The only problem is that they
are heavy. Two important brake factors is, ALLWAYS a yearly
change of brake fluid and the right pads.
This 4x1,3/4" piston calliper, weights in at 4,84
pound! The calliper uses 4 pads for even disc pressure.These
callipers was used by the NASCAR teams until they where
out ruled. Only 2 pads are allowed. We will see if they
are up to my demands.......
Master cylinders for the clutch to the left, and the two
balance bar working front and rear brake cylinders. Suits
fine on Pantera original aluminium mounting plate.
measured in G-force, is a complicated story, greatly depending
on how the tires is loaded under during retard. The reason racing
cars use huge brakes are to withstand repeatedbraking. In a way that newer occur on the streets. Big size
calipers and fat discs does not produce higherbraking
G;s. No matter how big, red-painted and racy look the
brake system is, it is impossible to create more stopping
force than the available tire friction against the road.
Pad area does NOTaffect braking torque.
Big discs and calipers does NOT create tire friction.
Heavy braking force is a question of downforce, car balance,
tires and a matching brake balance. So, very much attention
has been paid to this matter, and, by making use of all four wheels
and not only the front wheels, to stop the car. As known, the
biggest rubber area is on the rear wheels of the car, and accordingly,
in my case, they should carry 1560 and the front tires 1040 pounds
during 1 G of braking for optimum braking power. But in reality
the car produce a weight distribution that gives 1144 rear and
1456 pounds at the front axle, or 56% of the weight at the front
wheels at 1-G. Briefly, this will lower the tire-Cf and thereby
reducing braking capacity by 5-10%.
A Porsche GT-1
will brake around 1,05 G over 100-0 km/hr. However, from 200-100
km/hr I am heavely beaten by the GT-1 as this car has better aerodynamics.
Wheels are original GT-5 Campagnolo 13x15 and 10x15. Today 15-inch
tires are hard to find. Hoosier and Avon still makes suitable
rubber. There is a trend to the use of larger diameter wheels
and lower profiles tires. This is just a trend, more than a good
tire. After speaking with some of the leading racing tire manufacturer,
I can assume that a tire profile of 40-45%, is about the best.
Compared to spring wheel rate, tires usually has
a rate of 1000 pound/inch. Tires also have a very good self dampening
caracteristic. The tire spring work is also performed with almost
non existent unsprung weight. And do not suffer from bumpsteer,
camber change or the like. As long as my suspension and brakes
does not call for more space, I prefer to use my 15 inch wheels.
To take advantage of the tire side wall flex. The Campagnolo and
racing tires also makes a very light combination, and wheel weight
is of vital importance for a sports car. One rear wheel is 39
pound. The wheels is a unsprung weight that must be controlled
by the shocks. A rotating mass, that must be accelerated in both
rpm and distance. 250 pounds of wheels on the car is no thing
but a serious sportscar destruction. One may perform quite good
ski pad numbers with low profile-heavy tires. Do not let that
misled you. Ski pad course usually are flat. Just wait until you
hit a series of unexpected bumps in the middle of a fast road
bend, and you are off the road. The Avon racing tires is of bias
ply construction. This has both bad an good sides. They are more
tolerable to camber settings, but has greater slip angles. This
means that if the camber is not perfectley adjusted for a specific
road, one will be faster than on radials. But it may confuse ackermann
and toe settings.
Cutting tire pattern. I just use the same as what could
be ordered from Avon. There must be a pattern, and it will
hopefully do some good if I happened to be stuck in rain.
The Pantera cannot use a front tire larger than 600mm (23,5").
Which makes 15-16 inches wheels the most suitable. Of course,
one can use 20 profile tires or raise the car to create
the necessary spring travel. But these types of rubber and
settings should only be used for show, not for those who
like fast cars. Most of the big wheels is billet stuff,
which in most cases makes the wheel by fare to heavy for
anythig but look.
Wheel alignments. All measurements is on the wheel (15
inch distace). Rear wheels has 2 mm toe in. 1 mm each wheel to
the middle line of the car, and 5 mm negative camber. Front wheels
has 6 mm negative chamber and toe according to driving situations.
is limited in caster angle. This is taken care of by the new front
suspension that uses 1 dgr Sai angle, then caster is only used
for driver feel response and straight line stability.
Pantera is well known for bad bump steer. The new front suspension
has zero bumpsteer over the used spring travel.
Is an interesting object. Especially with the larger slip angle
of the bais ply tires. That may vary the "effective"
toe setting by 10 degree during cornering. 100 % Ackermann is
used on regular road cars, while "racing" Ackermann
depend on tire slipangle. High speed cornering could use negative
ackermann, while tighter corner should use positive Ackermann.
Friction area. A
lot myths is circulating around tire dynamics. But her we
are looking at real physical life testings.
As we know, the coefficient of friction
is altering with area load. The less the load the better
the coefficient, therfore larger tires gives better grip.
However, if we try to calculate the balance of the car by
using input numbers of the tire size, we are getting a spot
of troubble. One misconception is that the tire contact
with the road would be met by air pressure in the tire.
Simply put, it means that if the air pressure is 2kgcm2
and the burden that rests on the wheel is 400kg so is the
contact area 200cm2. As we will see here so this is not
The two left tires are Avon racing slicks,
and the two to the right is street Pirelli P-Zero. There
is a huge different in footprint size, despite the fact
that they are the same size tires.
This is the Pirelli footprint. At 880p and 29 psi it gives
an area of 147cm2. Raising the inflation to 42psi did hardly
show any difference in area size. This sow two things...
1, the tread pattern is geatly reducing the area.
2, the construction of a street tire is much stiffer than
that of a racing tire.
Both left tires has the same diameter and a
tire pressure of 25 psi. As can be seen, the wider tire show
a shorter but wider print. The 10 inch tire has a print area
of 308 cm2 and the wider tire 340 cm2. At a load of 880 pound
The image to the
left show tire contact area in kg per square cm. At a tire
inflation pressure of 2kg/cm2, or 29psi and 500 kg (227p)
of load, we got 1,9 kg per cm2 of area. If we lower the inflation
to 1 kg/cm2, (14,5pis), the load per cm2 will be reduced to
1,42 kg/cm2. If we divided 500kg by 1,90kg/cm2 we get 263cm^2
printarea. When lower the pressure from 2 to1kg cm2, we got
500/1,42=352cm^2 print area. So, half the iflation pressure
gives 34% larger contact patch, not twice that much. A note,
the tire does not carry the same load over the contact area,
and the contact area is not in direct proportion to inflation
pressure. A big amount of the advantage of wider tires is
that they should be used with lower pressure on the same car.
We can imagine the tire having a very
rough tread pattern, like this piece of wood, equally
spaced around the tire. We should then have a contact
area of 72cm2, giving 5,5kg/cm2. We can also note that
the tire does not deform very much from this artificial
tread. We can also draw the conclusion, that when the
tire rest on the ground, the actual pressure is not
equal over the entire tire footprint.
The coilower is mounted in front of the front upright bearing.
This makes the weight of the car to mainly load the front upright
bearing, placing a smaller load in forward direction on the upper
A-arm. The rear bearing does mainly support acceleration and braking
Second version. Better bolting pattern to the
chassis ans smaller outer bearing house.
Rear upper A-arm. Made to match the new front
Left. When making toe or camber adjustment, just unbolt
the front leg of the A-arm. When alignent is fixed, adjust
the length to suit the new angle. No bindings then.
My new (own fabrication)
uprights.This is a "BOX"
casting. With no open sides. This makes a tremendous difference
in twisting stiffness. This one weights 8,8 pounds. Original
steel is 13.75 pounds.
New A-arm layout. This should make room for
larger exhaust pipes. It also has the benefit of greater stifness
to distribute vertical load to the rear bushing of the uppright..
Tightening rear axle nut.
Construction sketch. The shaded area is
the stainless bearing holder. (Pictured above with the
outer bearing mounted. The bearing play is set by shims
between the axle yok tightened by the axle nut. There
are two sealing boxes outside each bearing, running
directly against the inner bearing race. Even the inner
bearing must have a turned seat in the upright. What
cannot be seen on the drawing is that the inner bearing
has a 1/4" smaller outside diameter, but is slightly
Combination of needle roller and ball bearing for the lover
uppright axle makes for an exact suspension movement.
The axle tube is fabricated out
of bearing material and is the inner roller race.
Halfchafts. The one on the top is
factory lenght. I cut 1,2inches away from the big end. Exposing
a longer portion of the smaller diameter axle. This makes
more room for exhaust pipes, plus saves 1/2 pound.
The upper ball joint is an sperical
standard bearing. A special insert locate it in the A-arm.
The uppright. Lower image, a lot wear has occured
at the aluminium castellation holding the disc. The wite marker
is an inlay to take up the play.
Lower image, the rear A-arm with dual coilover
mount. Alter the wheelrate from 120 N/mm to 76N/mm.
The slightly changed geometry of the rear suspension
in order to be able to use the different coilover settings.
There where no problem whatsoever to take the entire suspension
apart after two years of duty. No problem with the conical
bearing in the uppright.
Front A-arm system, longer arms, more parallell
and thereby less camber compensative. 1 dgr spindle angle.
Bumpsteer adjustment at steering rodend.
Spindle parts. Lover balljoint is Saab.
Caster is schimmed to spec.
Upper spindle joint bearing and bolt.
Sway bars, are
commonly named "anti sway bars", which sounds like the
whole idea behind the bar is to protect the car from sway. The
sway bar is a balance tool, f,ex if the road is wet we may need
some more front end grip. This is achieved by reducing the front
bar rate. Or, should we say, allow the car to roll a little more.
In other words, more roll - better grip. The spring rate of the
bars together should be just high enough to give the car a suitable
"sideway spring travel". Without making the suspension
to bottom out. Or to prevent ground contact, during cornering.
A good set-up "sideway suspension" help even out
corner peak loads, not to chock the tire grip.The spring rate
balance between the front and rear bars should then be used to
balance over-under steer. The drawback of to much roll is gain
in positive camber . The harder the bars, the harder the
outer tire peakloads become and the tire heats up more. I use
a spring rate soft enough to permit a roll of a roll of 1,5 degree.
It is also worth mentioning that different roll bar stiffness
does not affect the amount of weight trasfered
to the outside wheels during cornering. I will only affect the
distribution ofweight front-rear, and how
hard the transferred weight will hit the tire grip. The
transferred weight is a product of centre of gravity height, track
width and speed. Shocks gives this movement a "time factor".
To take full advantage of the roll, A-arm angle are very important
for proper roll-camber and road contact. Hollow swaybars? The
rear bar of the Pantera weight 8,8 pound. A hollow will save 5
pound for the same springrate. Pantera swaybars is located at
the lowest point of the car. So there is no value for the money.
I rather use the money to reduce both more and hihger located
weight in the car.
The front sway bar of the Pantera has a spring ratio of
0,16. This means that the bar spring rate are to be multiplied
by 0,16 A bar with a spring rate of 650 pund/inch, times 0,16
is 104 pound/inch at the wheel. The equation is, bar attaching
point length = 135mm A-arm length = 335mm equals 0,40. 0,40x0,40
= 0,16. Rear motion ratio is 0,70. The same is true for the springs.
Motion ratio is 0,71 front and 0,75 rear. Just multiple those
numbers with spring rate and you got the wheel rate. To calculate
motion ratio for the springs, the angle of the coil over must
be taken in to consideration. However, this numbers does not apply
to my new A-arms.
Spring wheel rate.
Are 386 pound/inch front and 585 pound/inch rear. I am talking
wheel rate, as this is the rate the car uses against the road.
Wheel rate is less than spring rate because the lever of the A-arm.
Divided by the car weight we get spring frequencies, a number
that show how hard the car is sprung. This numbers are 3hz front
and 2,8 hz rear. Together with the roll bar this balances the
weight distribution off 62 % rear and 38 % front to almost neutral
steering. Equally important are where the masses is located on
the car. And they should be located low down and in the centre
of the car. Ideal for the Pantera since it has no ground effect.
If there is anything I really miss on the car, it should be a
better design under body. My first Pantera was even heavier in
the rear, 66%, and accordingly show better braking numbers, but
more sensitive to tune in corners. Shocks are Öhlins.
New shockabsorbers from ÖHLINS.Supposed
to be about the best there is. We will see the comming season.This
set up is fabricated specially for the Pantera, with shims
and springs for my car. I decided to sort out a racing set
up, so the car is sprung to 3 Hz as a starting point
1060mm height help eliminate roll.
Racing cars use very hard springs, and close to ground
settings. Racetracks usually are very flat. Apart from regular
roads where you meet all kind of obstructions, different surfaces
and up and downs. I use a ground clearence of 3 inches. This is
about as low as I can get with a resonable spring rate. Even with
3 inches I had a few ground connections. For the same reasons,
bumpy roads, a streetcar can take advantage of its lighter brake
equipment, to make the wheels follow the roads better. Therefore,
to be fast on the roads, stay away from stiff racecar
settings. Go cart feelings does nothing but slows the
car down. It is not the way that firmer springs and bars makes
the car gain road grip. It is the other way around. It makes the
car loose grip. When the a car is tuned faster(more
road grip), usually by lower CG height, geometric, wing and rubber
actions, the car must use more springsbecouse
the added speed capability put bigger loads on the car. Ok,
depending on A-arm geometry we might want to stiffen the car to
retain proper camber angle, but thats strictley racing stuff..
Therefore we should newer use more spring than necessary. As for
references, the Panoz racing car has a front wheel travel
of 10 mm drop and 25 mm bump. Rear wheel travel is 25mm drop and
Pantera A-arm geometry is not much to be proud
of today, creating a miserable change in spring-wheelrate and
a few other undesirable effects. F-1 cars use long and very much
parallell A-arms. That way we got insensitivity to camber vs ride
height variation due to aerodynamic force without affecting camber
compensation too much. The F-1 theory does not apply very well
to this sort of sportscar, but some of the thinking is usefull.
What I am trying to do here is to keep rollcentre height at the
same level and GRc lateral movement under control in order to
keep weight transfer and its distribution, geometric-elastic front
to rear the same during roll.
Top, original Pantera front suspension geometry.
With the low ground setting there is quite a steep upper
A-arm angle. Also the lower arm has lower pivot centre in
the chassis. Not the very best, allthrougt giving acceptable
roll centre height. One other problem is the SAI projection
point that hit the ground at 1290 mm distance, creating
a big scrub radious.
Top, original Pantera rear geometry.
Very short instant centre gives a "swingam" like
wheel travel. Together with a large scrub radious, wheelrate
is getting lower. I made up a formula, for use in an excel
sheet, showing what happens. =(SIN(C2*3,14/180)*(B2*F2)/(A2*(F2+E2)))^2
The new A-arm geometry, front. Rc
at 11,2 mm.
New rear geometry. Rc at 30 mm.
This is the FRONT suspension. The geometry used
is such that the roll centre height is keept within 0,2 mm
during 1,5 degree of roll. Also, the jacking forces are almost
neutralized over the left and rear sides, so very little lifting
movements are present. This means that the rollarm remains
pretty much constant over the roll-movement. 1,5 dgr of roll
means 0,8" of deflection, or 20 mm. With that in mind
I set the rollstiffness so that I got 20 mm of deflection
at 1,3 g of cornering load. As the CGH is 415 mm or 16,3",
I got 415-11,3=403,7mm rollarm. Sprung weight is 1000 kg.
1000*1,3g =1300kg. 1300*0,4037= 525kpm of Mot.
This means a rollstiffness of 404 kpm per degree. Total
Wt = 415mm* 1,3g *1220Kg/1560mm=422kg. The outside pair
of wheel is then carrying 1032 kg which means 85% of the
As seen in the drawing to the right where the car is under
roll, the geometric Rc has moved 73% of the Tw to the unloaded
wheel side. Idealy it should have been 85% according to
the Wt number. However, the forcelines are low so the height
difference at the side of GRc is low, which show the advantage
of low forcelines. To cure the problem I could lower the
Cgh to 300 mm, which is not easy. Another solution is using
more parallell A-arms but then the cambercompensation situation
is getting vorse. Low forcelines and long A-arms does also
gives the benefit of less lateral scrub during heave, good
braking nd acceleration grip from less vertical movement-camber
change, or if aerodynamic downforce is present. Low Cgh
is mandatory from all points of view.
The rear suspension is not showed, but A-arms are shorter and
thereby victims for a larger compromice. GRc is only moving 195
mm resulting in a larger jacking force. I tryed to keep the cambersituation
as equal to front as possible and the outside front is -1,28 compared
to the rears -1,4 degree @ 1,5 dgr roll.
This is a model used to check out body-roll depending on
Rollaxis angle. I has been a lot written and talked about
this phenomenon, but I dont know if things are sorted out.
Computer program is great, but to me a physical model is
very dependable, and this model is able to handle both right
and left tire grip load, which is very important since load
affect jacking forces.
As the model is set up here, we are having a very high
Rc in one end of the car and an almost ground level Rc at
the opposit end. In this case the model show that weight
distribution front toreae has an influence on the precentage
of geometric antiroll of the car. However, this setup is
not really used on any car, but it show the principals we
have to deal with. Using longer and more parallell to ground
A-arms at all four corners will take the hazzle out of the
calculations and make it much easier to deal with.
Even if the term Rc appear a bit dizzy, in reality it is
not. With a properley designed A-arm system Rc can be pretty
much fixed at the centre of the car even as the GRc is moving
sideways. Rc is useful for establishing the rollaxis.
New Pantera design.
Recently there was a new design, or should I say new dressing,
for the Pantera made by someone thinking it needs a new
look. Ok, from my point of view, the look should remain
pretty much the same as before, although 2 meters wide 1
meter height and 4,1 meters long and some modified fenders
for larger wheels, as fare as design is concerned. Then
the similarity will end, a totally redesigned chassis. Front
track 1670 mm, rear track 1645mm, wheelbase 2500mm. Ground
setting 70mm. Rch 15mm, Cgh 300-350mm, weight 950kg, zero
antidive and squat, Front and rear SAI 1 dgr, scrub front
15mm and rear 20mm, 30% Ackermann. Brakes are 12" discs
x 1,25. Hight mounted rack and pinion which takes another
A-arm layout. This will do away with roll and bumpsteer
troubble, and at the same time get rid of any 3:e A-arm
leg influence from a steering rod monted in between tha
A-arms. Pushrod suspension. Front and rear frame lower tubes
together with the A-arms is using a higher location in order
to house an aerodynamically efficent bellypan and diffusors.
Totally new design spindles and upprights located in a way
that reduces internal loads and also on both steering rods
and rear toe leg rod. Pushrod angle and location is such
that A-arm load is greatley reduced. Rc is adjustable by
horizontally mounted inner A-arm bushings and spherical
bearings is used in moost cases as they permit better forceline
centre in the A-arm legs. But even a few heimjoint is used
for adjustability but mounted in such way that they recieve
straight loads. I was figuring the car should be right hand
drive as European tracks are mostley running clockwise.
The floor is marked green, and the feets will be higher
becouse of the raised front structure. A-arm attachment
are blue, rack&P is yellow and wheelcentre red, just
so we can compare to the original Pantera locations.
The scale of the drawing is pretty exact, but is only showing
the main tubing for simplicity. Triangulation is very much
Photoshop image to visualize what the Pantera may look
like modified according to the drawings. I didnt put to
much effort using Photoshop, just eough to get an acceptable
image. Front air dam is moved forward for better splitter
function. Wheel house openings are rounded and moved up.
Wheels are 18". Car is 1000mm in height. And the diffuser
together with radiator air exit out the side. Rear diffusor
The intention is not to create a better looking Pantera
but to house a racing chassis in a body still looking as
much as an original Pantera as possible.
Corvette C6 and Viper suspension.
As for comparsion I made a scetch of the Corvette and Viper
suspension system. One might wonder what the engineer come
up with for those cars as they provide a fairly good ride
while still maintaining braking, cornering and acceleration
performance that good. There is a lot to be said for a comment
to these drawings so I want go in to details, but so much
can be said that those cars are quite soft in heave and
to cope with horizontal forces they have a good deal of
anti:s in all directions. The Corvette is on top and Viper
below. To the left we have the front and to the right the
rear suspension. Middle part is the cars seen from the side
where the CGH line is common for both cars for an easy comparsion
and the wheels on the sides is seen from the rear or front.
I was figuring of making a Ohlins coilover setup for these
cars if time so permit. The idea is to create a sporty set
up more suitable for road racing.
This is what the car looks like under 1g of cornering.
The car should be driven in a circle along the white line.
Lap-time is measured with a photocell
test, with the GT-5 in stock condition
with the 351-C and original wing location, could hardley
corner more than 1.G. Clearly showing that the Pantera
aerodynamics does not work. A Penske
indy car has 3300 ibs ground force at 165
mph, at the cost of 1119 ibs of drag. A cart-car with
well designed wings can turn 4 g:s. Porsche
911 has a lift of 600 ibs at 150
mph. Ferrari Enzo a has a downforce of 760
ibs at 125 mph with NO wing, due to good under body. And
corners 1,4 G. Numbers that speaks for itself. Koenigsegg,
claim a cornering capability of 1,15g a great number,
but still 0,25g lower than the Enzo. Both Enzo and Koenigsegg
talk "cornering capability", which should not
be confused with skipad numbers. A corner is a corner
and skipad is a complete 360 circle. So the 1,4 and 1,15
g will be reduced on the skipad.
630 fp@5300rpm 869Nm
Acc @ 50 mph
0,88 G in 2;gear
According to Cygnus computer, which is an on board computer
with mecanical sensors that measure wheel rotation, crank
rpm etc to measure performance, 700 hp at 6600 rpm, measured
installed in the car with 20 disc Supertrapp. Eqvivalent
motors by Ray
Barton produce 775
hp and 700 foot pound of torque, in the bench dyno. I tuned
the headers at a little lower rpm than max HP. The ZF gearbox
limits fast starts, as one cannot let the clutch go at high
rpm. Gearbox will probably break from the added kinetic
energy stored by the rotating mass. But it does seem to
handle the torque itself well. Now I am not too concerned.
This is not a 1/4 mile car, so a road racing set up is used.
All numbers are with the previous intake system. Interesting
to check the new system.
* Braking speed 60 mph. ** Test is made in a circle of
200 foot diameter. Test is run on non heated tires, to simulate
Weight. 2600 pounds. My first Pantera was 2398 pounds!
With a 500 cui Ford. With the 302 boss it was 2343 pounds and
made the quarter i 11,7 sec. Why is the Hemipanter carrying around
with 202 pounds of extra weight compared to the 500 Ford installation?
Second, is it really possible to come down to 2398 with an IRON
block big block??? What is the secret? Answer, there is no secret.
Drill holes in every bolts, plastic windows, fibreglass hoods,
small battery, no frogeyes, etc, etc. Concerning the Hemipanter,
I was in mind to keeping it kind of original. Putting on some
heat when chilly. In a few words, I liked this car to have at
least some kind of comfort and appear original.
Karbon fibre rear deck lid. 13,2 pounds yet very strong.
This particular hood had a sew problems like to bent roof
profile. I try the trix of bending it straight and reinforce
with fibre glass. It has gelcote on, so it has to be painted.
No carbon fibre show off, to bad. Very light doors and even
the door hings are lightened.
The Nordic Supercar
is an interesting cup with big, fast powerfull cars
using V-8 snd V-10 enines. The Speedlab Racing Team
have given me the confidence to design their new Corvette
racing car from a clean sheet of paper.The old car
is the yellow Corvette to the left, which is an USA
built C-3 Trans Am car from the 90:s.
Me, standing, and the Speedlab guys loking at drawings.
Planned design of
Breif design of the front wheel centre line
cut seen from the rear. Engine is offset to the right.
18 inch wheels 13 and 13,5 inches wide, 650 front
and 710mm rear diameter tires from Michelin. Total height
40 inches = 1000 mm..
Here a prototype front and rear upprights
made from cartoon paper that is going to be fabricated
in chrome molly steel.
Chrome molley sheet metal for the rear
Evacuation permits very short hoses to
the pump. The low mounting location does also ensure
good starting up oilpressure. Oil evacuation permits
very short hoses to the pump. The low mounting location
does also ensure good starting up oilpressure.
Showing HM damper and oil pump drive.
I made a new hub with a longer "neck" to be
able to mount the belt-drive-wheel on the inside of
the HM-damper. Pump is as low mounted as possible.
Header fabrication. Image also show the
low mounting of the oilpump and special bellhousing.
Headers are seven-Y designe and is having
a megaphone after the last Y.
Engine mount plate.
Rear mounted starter motor.
This is the twisting test of the chassis. The front bar
is anchored to the floor at the outer end and is resting on
a floating stand in the middle, all to elminate bindings.
The "starting out" twisting showed a mear 4000 fp/dgr,
where the largest nuber was read in the engine section of
the chassis, and the roof as a good number two. After crossbracing
the roof and mounting of the engine the number went up to
8000Nm/dgr. Bar is 2 meters long for an easy Nm reading. The
centre of the rear is also ancored to the floor, hanging in
a wire. The chassis is lifted up from its "resting"
location during the test.
By using telescopic tubes I detected the largest flex to occure
in the front window area, 1/8", so an diagonal tube was
welded in place as seen on this image. Now the redaing get
18000 Nm/dgr. We still got a 1/16" flex in the engine
section, and the coupe floor that is describing "waves"
under loads. I am looking for (hopefully) some 30000 Nm/dgr
as a final result.
Wind tunnel testing.
To find out the best wing profile and its
location on the car, I performed asimple wind tunnel test.
Here is a 1:30 scale model of a "fantasy" car, it
has a front splitter and an adjustable rear wing.
This is the underside
of the car which is pretty much like what is used on the real
Corvette race car.
Observe, I banned
the use of any bent tubes in the new part of the chassis.
The Old trans-am part (red) is and was full of them,
which made it no (better) stronger than a wet dischcloth..
New wing profile.
A new wingprofile I worked out in my windtunnel.
It is for low speeds, say 100 mph. This is a coutout
from 1/3" aluminium sheet, in two pieces, which
is then mounte in a cellplastic cutting machine to form
a light body to be covered in carbon fibre.
I am fabricating the "swan neck" that is
holding the rear wing. The front edge is made round.
Ther are cutouts in the aluminium to make it lighter,
the holes are then filled with balsa wood to lessen
The new diffusser.
The new front diffusser
This is the third spring to cope with vertical
downforce at higher speeds.
Since the Corvette wheel broke down I decided to make my
own set of wheels.
This is the basic shape watercut aluminium.
Mantorp 21 sep 2009.
This is the first real track testings of
the car. At Barkaby the 31 august 2009.
We have had problems with some understeer so I rebuilt the
diffrential. Instead of the load-sensitive plate pack I made
a new packages using a roller bearing which makes a completely
open differential. It's not quite what you are accustomed
to seeing on a race car but this car has an incredibly low
center of gravity so I thought it was worth a try. It turned
out that the driver was very satisfied. Now we can use a more
balanced coilover-spring setting.
This weekend, 12-8-2012, test-driven the car with the new
diff and the result was two victories in two races on Anderson
Stop Raceway. I am really pleased with that.
This weight numbars would make for a great Pantera race
car. To bad there is no money handy for such project.
As we where talking sway bars a few treads back I recall making
a sway bar full scale test a few years ago.
The idea was to see what difference the angle of the sway bar arm
made. So I made a number of bars with different angle arms and loaded
them with weights. Sorry to say that I dont remember the diameter
of the bar, but it doesnt really matter in this case. The
thing is that the angle of the arm is seldom mentioned even as it
has a big influence on the function. As we can see on the picture
the first loading on a 90 dgr arm produce a deflection of 120 mm.
What do you members think the deflection will be for the other four
bars? Just a rough guesswork is Ok.
How do we analyze the difference of what happens?
Here is a spring problem. Nothing very hard for the engineer,
but I know there is a lot misunderstanding about the issue. So bringing
it up may be a good idea.
The problem is what happens when two springs are loaded against
each other. There is a plate C, between them and we are trying
to push this plate to the left press one spring together. The
springs are having a rate of 1kg per mm each.
A1, both springs is just touching the plate, which means that
as soon as we push the plate in one direction it will produce
a resistance of 1 kg per mm, and the other spring will come loose.
A2, If the plate is pushed 10 mm we must hold it by the force
of 10 kg then. The opposite spring is is out of influence as soon
as the plate is moving since there is no preload in the starting
B1, here both springs is having a preload of 10mm, a force of
10kg each. We are now trying to push the plate to the left again.
B2, the question is wether or not the right side spring by its
pree loaded force will help us pressing the left spring together.
What will be the needed force to move the plate 10mm to the left?
I am building a new engine, the old iron block
is switched for one made from aluminium. This saves weight while
at the same time offering the oportunity of having more cui for
almost no extra money. 4,5 stroke and 4,5 diameter makes for 572
cui. Block, crank, rods, piston and gaskets was delivered by S&S
Mopar shop owned by Steve Bowman.
Everything is cleaned and put in to boxes waiting for the new
aluminium block to enter the scene.
After the engine was taken out of the car the rear lower crossmember
was cut out in favour for a nicer and lighter and stronger piece
of steel. A diagonal bracing was installed.
The new aluminium engine block from Indy Heads
The little short beam had over the years gathered in a lot of
sand and debris, one pound.
Now for the new engine mou-nts, this requires a properly made
cardboard model. It is important that the gearbox and engine are
exactly centrically against each other. Engine must also be positioned
correctly both laterally and horizontally. After that, I've cut
out the shape in an aluminum sheet which is 6mm thick. Here it
is placed in the car for some final adjustments. The engine plate
also braces the rear of the car and put engine-gearbox weight
right over the coilovers.Less load in the chassis.
Engine front mounts is much better possitioned this way than
The shape of the pistons is important so I made a mold
from plaster and send it to the pistom manufacturer. The piston
recievd was not exactly the same probably due to machining
equipment, but they are good enough. A flat quench area and
a curvature dome following the combustion chamber roof for
a better burning chamber.
Eagle rods 7,1 inches long. Beehive springs with a small
diameter retainer is perffect to fit inside the valcovers
without hitting the cover.
Orange shell Hemi com-bustion chambers
should be avoided. This is the chamber to use for dual plug..
I need a fresh surface on the flywheel-clutch, this is a great
way to do this myself.
Indy block with special made water outlet holes to fit Chevy
Gear shifter rod is supported by the engine
Shifter rod that is in straight line with shifter handle.
The gear shifter is mounted in an angle
to fit the engine location and promote ease gear shifting.
Engine lifted in to the car, great day!
Left, gas pump and oiling sytem.
Right, headers mounted, this is a great fit without the Pantera