................ .. ...............
............. . . My
have been building guitars for 60 years. I have had customers from very
early time, like Bill Healy.
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. The picups is hidden
and mounted from the back side. Each pikcup has its
own channel and two amplifiers is 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 good sustain.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 hardley
will be duplicated. One black and one cream. Picups
that has to be listened to before speaking "copy"
PAF sounds". It is specially the dynamic properties
of the picup that is amazing.
The Abba guitar.There
have been rumors about who made this guitar, as well as the exact
design. 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.
ABBA with the star shaped guitar at the
Eurovision song contest. Brighton.
Reconstruction of the guitar.
Some of my guitars are now showing at
the Guitar Museum in Umeå. In addition, a mandolin in Les
Paul design. At the top of an Explorer design but with corvetd top.
Likewise, the Stratocaster at right has curved top in mausury birch.
Me, Björn Ulveaus and Björn
Clern, as well as the Abba Museum jubilee guitar.
Zepelin 1969 using my speaker cabinets.
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.
Here are some songs I recorded. Ghost rider and
Apache are covers, the other songs are own compossitions. I use
the bass as a melody instrument and have laid the backgrounds
with a Kurzweil keyboard. Click the picture to listen and see
Apache, med Speedlab Corvetten.
Klick the pic to see the movie and listen.
Skuggor, own composition.
Ghost Riders In The Sky. An old song.
Rain, own song song about rain..
Preikelåten, own song played on a cliff called Preikestolen,
Powerlifting has interested me since the 70's. Sadly,
I have to undergo surgey just over ten years ago that stopped me from
lifting for 6 years. After that, I practiced a bit more quietly. At
one point I read how the record in the bench press looked like and I
thought that I might be able to beat. I started training more purposefully
and the results began to come. I moved the training to my old club STK
in Sundbyberg which is an established competition club with world names
among lifters. There were some club competitions to start with and after
a few years SM competitions. I beat the Swedish record in the bench
and in a short period I also got a European record. To date, I have
Gold in SM and EM Silver in total as well as individually in the squat
Click the picture and yo see a video from my heaviest
bench press at 175 kg. Not a perfect lift, but not a total failure.
Click the picture and you see a video from my lifrt
in European Championchip in powerlifting, Pilzen Tjeckien.
This is the Silver place in Luxemburg Hamm 2018 European
Cahampionchip in only benchpress.
How the hemipanter was built up.
Why a Hemi? It is a legendary engine. In fact, it is the
world's most powerful and fastest engine there is. It holds the
top fuel 1/4 mile record. The Hemi is like having some racing
history in the car.
Heads. 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 are 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 13,5:1 cr ratio, and a nice
Engine is configured for alcohol use, E 85. Block is Indy
aluminium Hemi . Crank 4,5 stroke billet . Rods
7,1 inch steel, ratio1,58:1. Piston 4,5 bore and 13,0:1
Cr. Heads aluminium, ported by KB. Aluminium rocker stands.
Valve spring 200 pound seat pressure. Retainers titanium.
Camshaft 264 degree@ ,050 roller. Intake, Rebuilt
Weiand tunnel-ram manifold. Oil pump KB. Damper ATI. Oil pan, 11 quart wet sump. Exhaust headers 4
to1. Crank trigger hall sender and 30 tooth lost
I build an all new aluminium engine.
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.
The engine plate also braces the rear of the car and put
engine-gearbox weightover the coilovers.
A diagonal bracing was installed under the gearbox.
The shape of the pistons is important
so I made a mold from plaster and send it to the piston manufacturer.
The marking on the piston is wherw
the sparkplugs are located
This show what the HEMI combustion
chamber should looks like.This chamber use dual plug and ofer
short flame travel.
.The heads has steel rockers and
Eagle rods 7,1 inches long.
Indy aluminium block converted to
SBC water pump.
Gear shifter rod is supported by the engine mounting plate
The gear shifter handle is mounted in a straight line with
the gear rod to promote easy gear shifting.
Gas pump and oiling sytem. Engine front mounts is much
better possitioned this way than original Pantera.
Beside the drivers seat. Observe the distributor which
now is only used for crank possition signal and oilpump
New composite firewall door. Very
light 4,4p flat with insulation and bolts.
I need a fresh surface on the flywheel-clutch,
this is a great way to do this myself. This way of grinding
the flywheel works great.
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.
I used a standard roller timing
drive from Comp Cam:s, and machined all surfaces. An aluminium
bearing centre was fabricated.
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".
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.The diameter
I use a Swedish system MAXX Ecu. I did all the
injection programming on the road. I used a lambda sond for
analysis. 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. The engine consume 15% less fuel compared to the
carb. 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 .
The sensor for speedometer sits on the output shaft
of the transmission. Then I will not have the 3-meter
hastighetsmätarwiren that only malfunctioning and
also do not show the correct speed. Electronic meters
can be calibrated precisely. I use a simple hall sensors
which only costs $ 4.
Is a story for itself in a wet design and this very low
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, but it can handle an extra 2-quarter. The
pan is safe in "normal" driving using 4 quart.
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 .
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.
The oilpan is a tight fit between the frame legs. It is
flush with the underside of the car
Headers are 31 x 2,11 inches, giving the engine a peak at 5500
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.
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. 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
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.
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 card
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..
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", 0,46mm.
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.
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.
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 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.
This is the cooling air outlet director. A single
powerful fan from Audi fabricated by Siemens, is used.
.Fabricating a new front hood in fibreglass.Sandwished
with bonocell layer.
Coupe, seats, dashboard, bumpers.
Lighter suspension bolts.
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
A thin layer of light trowel smooths the fabric pattern,
but only on the outside. It weighs 215 grams, complete with
bolts and everything.
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, ALWAYS 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. The Campagnolo and racing tires 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. 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 case.
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 show 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.
(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.
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 wider.
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.
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.
Front A-arm system, longer arms, more parallell
and thereby less camber compensative.
Spindle parts. Lover balljoint is Saab. 1 dgr
The front sway bar of the Pantera has a spring lever 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
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. 2350 pounds. How is this possible?. Drill holes
in every bolts, plastic windows, fibreglass hoods, small battery,
no frogeyes, etc, etc. Even so, I is trying to give the car at
least some kind of comfort. Like some heating system when chilly
and electric wipers.
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..
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.
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..
Engine mount plate.
HM damper and oil pump drive. I made a new
hub with a longer "neck" to be able to mount the
belt-drive on the inside of the damper.Oil evacuation permits
very short hoses to the pump.
Rear mounted starter motor
2016. It has been a few years
since the car was constructed, and it is time to update it
in a number of areas. Both in terms of things that have not
worked to satisfaction, as well as more modern designs developed.
We also decided to run the "Time Attack" racing
because the car is difficult to classify into the competitions
running in Sweden. So far, time attack is a relatively free
class in terms of modifications that are allowed. So we built
a new front, new splitter with diffuser and two turbochargers
and sequential fuel injection and ignition.
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
email@example.com Payment should be done in advance
to the e-mail adress firstname.lastname@example.org
€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:- inkl frakt.
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.