How would you design a new GT40 from the ground up?

[Jim Rosenthal]

Well, you know, it is a nice-looking car but you can tell they've changed the shape of the roof, it kind of curves up. I still like the original shape better.
There was a car built in the USA in the thirties called the Cord 810 and 812 model. It was really beautiful in a weird way; at that time drivetrains weren't as good as they are now, and frequently Cord owners would later on take out the Lycoming V8 engine, sometimes they took out the front-drive system (one of the earliest uses of CV or Rzeppa joints) and put in a rear drive system. But, people didn't change the way the body looked.
I think the GT40 is like that; just about perfect the way it is in its' Mark I shape, and if a new one were to be built the real challenge is to put updated mechanicals into that shape and size and make better use of the room in that envelope- without altering that envelope. Changing the outside is kind of like sending the Venus de Milo for plastic surgery- there's not much point, but there is much wasted effort.

 

[Guest]

All aluminum monocoque. Aluminum works fine for a low mileage vehicle. All you have to do is increase the sheet thickness over mild steel and strengthen/redesign suspension and drivetrain pickup points.

4.6 quad overhead cam all alum V8 out of a late cobra mustang, with HP mods and 8 t/bodies

quaife 6 speed

carbon fibre body

TITANIUM, weldment uprights, suspension arms, drive axles, and exhaust system

carbon fibre brakes

chameleon paint job so you can change colors if you get bored with the color or are running from the law.

and an afterburner out the back like the batmobile, or at least a small propane tank feeding out the back of the exhaust with a ignitor so you can freak out the kids.

and while were at it (before someone wakes me from my little dream). A playmate for the passenger seat.

 

Hey Chris,

Is the Meyer GT40 made with an aluminum chassis? Or is it steel?

Very impressive either way.

Doug

 

[Ian K]

Kalun, since you're dreaming, how about 100%
ceramic engine - block, internals, etc.?

I concur with carbon fibre body, and titanium
stuff, but I'm quite happy with the RF, CAV,
GTD, and ERA cars as is.

Ian

 

I've always read that turbos are good for high end power. Superchargers are (mostly) more for low end power. I've also seen twin turbos and superchargers.

Is it possible to put both a turbo and supercharger on the same engine? The supercharger would be great for a good amount of grunt off the line and the turbo would kick in later as the supercharger fell off. It may also give a good mid range amount of power, between the two.

 

[ChrisL]

May I just pose some light hearted questions to the forum?

Given that the original question was "How would you design a GT40 from the ground up", at what point of variation would you consider the new design to no longer be a GT40?

To take this question to its illogical conclusion, concider that the design spec of the original GT40 was "To win LeMans". Given that every LeMans winner since 1970 is by definition therefore "better" that the original GT40, are they not in effect ALL "better GT40s"?

Just a final point, all LeMans winners since the GT40 used ground effects to achieve their level of handling, so is it fair to say that there has NEVER been a better mechanical-grip LeMans winner built since?

.... should stop having those late night red wine sessions - they just get me all philosophical

 

[Fran Hall RCR]

In reference to both supercharging and turbocherging the same engine,yes it is possible and was done to great effect by Lancia with the group B rally car called the Delta S4 in the mid-eighties.It was the forerunner to the Delta Integrale.

 

[Jim Rosenthal]

This turbo combined with supercharger idea is very interesting. There are several big high=performance diesels that use this approach- a crank-driven blower for low-end grunt, and an exhaust-driven turbocharger to provide boost when the engine spools up(Volvo). It has the advantage of very fast response and consistent boost throughout the range with no turbo lag. It has the disadvantages of more stuff to tune,and to break, and lots of complicated plumbing. Diesels use quite a lot more air than gas engines, and some of these turbos are the size of a Mini-Cooper engine. There are some other applications that use multistage turbos- a little one that spools up really fast and then a big one that takes over(MTU). Personally, if I needed that much power, I'd opt for a crank-driven blower, where you don't have the turbo lag and you have the advantage of an unrestricted exhaust system.
As far as Kalun's posting about having a suitably attractive playmate in the shotgun seat...sign under the Snap-On toolmate calendar in my friend's shop.." before you start dreaming,just remember, someone, somewhere, is putting up with her s---f."

 

[BruceA]

With regard to an aluminium chassis, remember that the alloy makeup has come along way since the 60's and that there are some very high tensile aluminiums available. Take a look at modern aircraft construction. They are all aluminium,(for obvious reasons !!). Careful thought and construction methods will enable you to build a very good, reliable aluminium chassis without the hassles of yesteryear.

 

I did a quick sketch, incorporating some of the ideas here and something became obvious...the dimensions will have to be increased. If we move the driver outward, toward the smaller sills, their feet are jammed into the wheel wells. So you have to move the driver and passenger back to allow for this. I don't think you would need to make the car as big as the Concept car but, you would have to have maybe a 5% increase in overall dimensions.

Doug

[ March 06, 2002: Message edited by: Doug Barry ]

 

Hi all

here is a photo of the Saleen GT1 chassis it got it all

 

The comments about Aluminium alloys being tougher than yester-year are very true...

You can now use 2014 and 2024 grade, which are heat treated, aircraft grade, and they have greater tensile strength than steel, and are much lighter... they are used in most modern airframes...

from these, a great chassis could be constructed...

BUT

none of the high tensile Alu alloys are very good for bending, and are very susceptible to cracking....

the real danger is that these cracks might not be obvious to the naked eye...

so unless you are very good with a brake/folder, and you have access to technical specification on minimum bend radius etc etc... then stick to steel!

Neil

 

Darth,

Unfortunatly it isn't that simple. It all depends on what type of setup you have.

Both Turbo's and superchargers in general normally give good low to mid range torque.

As mentioned before you can go a Twin turbo route which is supposed to reduce the boost threash hold and lag. This comes in a parrallel configuration where you have two small turbo's that work at the same time fed by half of the cylenders of the engine ie 3 cylenders per turbo for a V6 or 4 for a V8. Cars with this concept include the Ferrari 288 GTO, late model Nissan Skyline GTR and 300zx TT.

The other twin turbos are sequential like the Late model Toyota Supra or late model Mazda Rx7 where a small turbo is used at low rpm then when that runs out of puff the larger one comes in to feed it at high RPM. They both have the positive or negative aspects.

With supercharges it all depends on what type (roots, centrifugal, lysham (sp?) screw, etc..) will in general determine the characteristics.

Hope I shed some light

Cheers,
Danny

PS. maybe you could try the quad turbo like the new Bugatti (1000hp+)

'96 Nissan 300zx Twin Turbo
GT40...comming soon

 

[Guest]

Darth, the usual solution to this is two smaller turbos rather than one large one. The smaller turbos spool up faster and therefore have less lag time and can get the boost up even at lower RPM.

I believe that he turbo/super combination has been used before, but I am not sure it was a racing engine. I seems it was a truck or military vehicle, but my old mind is not clear. I am not as good as I once was, but I am as good once as I ever was.

 

I've done a little research on the turbo/supercharger thing. I'm leaning towards the twin turbo. One of the main reasons is that I've learned that superchargers are on all the time. While the turbos can be turned off. This makes a big difference in the life of the engine.

I don't know if I'll do it but some changes to a Fiero chassis to make it more like the original GT40 could be done. (It would look nothing like the ASPP cars.) If that was done it could look just like the original on the outside. If you did that it would have alot of positive changes like moving the tanks inboard away from the door sills. A V8 could be shoe horned into the back of the car.

There is going to be an article on stretching a Fiero in the nest issue of Kit Car Magazine. They also have an article on making body panels in their website. Some of the changes Jim suggested can be made fairly easily.

Anyway, it's just an idea.

Doug

 

[Howard Jones]

The car must have a sonic 427 and straight pipes ! I don't care about anything else!