Original 4 inch vs. Billet Poll

[Cobra Pack]

3 inch leafspring frame with correct steel suspension pieces. 289 leafspring cars handle incredibly well -- especially if you use OEM spec springs.

[RodKnock]

Originally Posted by Joe Wicked

CG is center of gravity.

Well, I would haven't gotten it if David had written "CoG".

[olddog]

Originally Posted by David Kirkham

In theory (not proved until tested).

Aluminum chassis is on the order of 300% stiffer. It should handle much better.

The suspension has been significantly upgraded and tuned to the best we could make it.

CG of the billet chassis is moved back 2 inches. I know that doesn't sound like much, but that is about the same a small block is moved back from a big block. An aluminum small block with all the aluminum goodies (flywheel, water pump, etc.) is lighter than the old iron block and heads 289's of old.

Fianlly, no matter how you look at it, the aluminum chassis is pretty cool.

David

I agree the billet chassis has a wow factor through the roof. 300% is impressive, but what does it mean in practical real world conditions? If you had 600 lb-ft of FE torque hooked to the ground some magical way, how many inches would the frame twist on the 4" round tube verses the billet?

What I am try to get at is short of racing would it really matter? Kind of like increasing Hp. At some point, short of all out racing it just doesn't matter on the street, other than the fact it will get you killed quicker.

PS:
I actually do not have an opinion until I understand the difference.

[David Kirkham]

Originally Posted by Richie18

As long as the car's exterior shape and look are kept then i think by all means suspension performance/technology should be pursued. How many times does anyone see the suspension on any cobra owner's vehicles? And if they did what would be at all disappointing about a suspension that uses new technology?

Why not make the car be able to better handle some 500hp when that is what is typically seen in these cars?

A billet aluminum chassis would impress anyone.

The exterior of the car is identical to what we make now. That was what made the engineering so difficult on this car. From 10 feet, an "expert" will not be able to tell the difference.

Now for my personal opinion. I have been fortunate enough to drive original 427 Cobras, original 289 Cobras, our latest car, and many other replicas. I won't comment on the other replicas (for obvious reasons) but when you get right down to it, I really don't like driving the original cars. The chassis flexes all over the place; the brakes are horrible, the motor is a ton of bricks in the front end (all of those comments can be applied to the 289 car as well, with the addition the leaf springs ride like a buggy.) Frankly, the only thing I really like about them is the incredible looks and the incredible acceleration.

I can tell within 100 feet of driving a car weather or not it has an aluminum or an iron 427 block. The 427 iron block ruins the car for me. Now, that is just my opinion and so there is no reason to start the flame throwers.

Other people (like Chuck) are certainly entitled to their opinion and that is why we make so many different cars. The world would be a very boring place if all we had to choose from was vanilla ice cream. Having spent considerable time in Poland (right after the wall fell) I can tell you I certainly didn't enjoy seeing empty shelves in the stores. The first time I brought Poles to the States and took them into an Albertsons they actually cried just looking at all the different flavors of Kool-Aid (of all things) that were available just sitting there on the shelf.

I digress,

Anyway, I'm just glad we have 31 Flavors here!

David

[Silverback51]

Well I have to say that from an engineering and manufacturing stand point it's very impressive.

When you did your FEM model analysis, what kind of loads did you apply and what were the resultant stress loads? Deflections?

How would this type of frame hold up to everyday use as far as fatigue?

And if you do not want to share this data, I can understand that you may consider it propriotary. But I am curious.

It's a work of art. Congratulations.

[ddcobra]

My vote is 100% billet sorry for the purist.

It's a work of art. Congratulations.

Don,

[David Kirkham]

Originally Posted by olddog

I agree the billet chassis has a wow factor through the roof. 300% is impressive, but what does it mean in practical real world conditions? If you had 600 lb-ft of FE torque hooked to the ground some magical way, how many inches would the frame twist on the 4" round tube verses the billet?

What I am try to get at is short of racing would it really matter? Kind of like increasing Hp. At some point, short of all out racing it just doesn't matter on the street, other than the fact it will get you killed quicker.

PS:
I actually do not have an opinion until I understand the difference.

You are right. Most of this whole exercise was WOW factor. What does 300% really mean? Not sure until I drive it! But be sure I will let you know. Should the car hook up better, yes. Will the customer actually drive it at 100%? Probably not; he is a really tame driver. But, we still had to engineer it as if he were going to drive it like a scalded skunk. But, that is the case with any of our cars. Our cars can usually out drive their drivers (I know they can me!) But, then again, so can a Ferrari, Bugatti, etc, and people still own them. Maybe it is just an inner feeling of WOW, THIS is what a car is supposed to be like--not that you could ever use it without losing your license.

David

[ENTDOC]

to me , this is what a cobra should look like and when the hood is opened the guts should reflect a similar trend.


and this is what a billet suspended modern framed car should look like on the outside

[David Kirkham]

Originally Posted by Silverback51

Well I have to say that from an engineering and manufacturing stand point it's very impressive.

When you did your FEM model analysis, what kind of loads did you apply and what were the resultant stress loads? Deflections?

How would this type of frame hold up to everyday use as far as fatigue?

And if you do not want to share this data, I can understand that you may consider it propriotary. But I am curious.

It's a work of art. Congratulations.

If I remember right (maybe not, so this is for educational purposes only)

I think we used 1000 pounds up and 1000 pounds sideways on EACH wheel cycled 100,000 times with a 15,000 psi yield.

David

[1985 CCX]

David,

I love your cars and maybe someday I will own a nicely appointed Slabside. It is a need that will need to be realized at some point.

As for the frame: 4" ROUND TUBE
Why: I love the cars for their classic drive
Preference: Slabside transverse leaf however I would sacrifice originality for the Coilover hybrid. 427 car = 4" ROUND TUBE.........
Why I love KMS: They are great aluminum reproductions of a great classic line of cars......Masterfully executed I must add.

To be honest the round tube frame is what sold me on the Contemporary. I love the Cobra because it replicates a historically significant car and drives like one. If I wanted a space age frame I would also want the corresponding body = Lotus, Vette, Panoz, or FFR GTM.

Would I ever buy a KMS Cobra with billet frame: No
Would I buy a KMS billet frame shrouded by a supercar aluminum boby: YES, after a KMS Cobra with 4" round tubular frame of course!

No tubes is like no boobs.........

[double ugly]

Billet goes toward the "HOT ROD" aspect of a Cobra. There are purists and then there are the "most anything goes" attitudes. I like the original therefore no billet. (although I have your billet clutch fork).
John

[David Kirkham]

Originally Posted by jmarsey

Good points being made here and there is more to it.

A pure design methodology would carry through the entire car, including the body, shape, wheel base, track, and all the bits, etc. In other words, why wrap a state of the art chassis with a period authentic 40+ year old wrapper? Why not carry your talented design sensibilities further to inform all aspects of the car?

Thank you for your kind words!

While I can't comment on the Skunkworks, the billet chassis is a preliminary exercise for another car. Let's just say, Thomas and my dream car--or the crowning jewel of our combined automotive talents, experience, and dreams. It has nothing to do with Cobras--and everything to do with what a modern car of today could and should be. One day I hope to see it drive down the road.

David

[Anthony]

David , how many Willy's have you made?

I guess you could slip that billet frame underneath the Willy's as well?

[David Kirkham]

We only made 1 Willy's. Certainly the billet chassis could be placed under just about any car.

David

[Lew Ledyard]

"While I can't comment on the Skunkworks, the billet chassis is a preliminary exercise for another car."

You guys aren't going to be making a "better" version of the Shelby GLH are you?

[David Kirkham]

You'll have to waterboard me to talk!

David


or just let me help out at your wife's next show...

[Lew Ledyard]

Originally Posted by David Kirkham

You'll have to waterboard me to talk!

David


or just let me help out at your wife's next show...

It would ruin you. You would never think about "aluminum" bodies again.

[David Kirkham]

I'll take my chances!

David

[ENTDOC]

I feel that I am missing some element of this conversation

[olddog]

Well after taking a long drive in my own Cobra and giving some thought, I had to vote for the billet chassis.

It is my belief that not only is a Kirkham a much better quality car than the original, but the people behind the car have 10 times the honor and character than ole Shelby ever had. I'm not publicly kissing up here, I think it is fact. Therefore, I have to think that some day in the future, Kirkham Cobras will be as valuable as the originals, or at least nearly so. Secondly, I do not think very many billet chassis cars will be sold, due to cost verses real world improvement. That being the case, some day one of these cars is going to be as rare as the 5 million dollar snake and will be worth that type of money.

I know I have been full of crap most of my life, but I think I am dead on, on this one.