Building a Frame?

[dude4you]

I found a picture of the original chassis on the internet but it i'm not very keen on building an exact copy of a original one. Anyway I would have to buy a body from any manufactors and it might get difficult to fit them together. Its more about to build a car which runs quite chilly on the road.

But nice idee.

[Robin427]

Great idea but unless you are an expert in welding and jigmaking, you could be setting down a dangerous road. As someone said - with 300+bhp going through the chassis, any errors in design and construction could be serious.

Pros and cons of the commercially available chassis available, they are all tried and tested. Buy a GD... shipping might not be as bad as you think

[Pictus]

or if you did want to go for the origonal design send this guy an email or goto his web site

coupechuck@aol.com

it isnt a link but if you cut and paste it will work his site is:

http://members.aol.com/coupechuck/index.htm same again i would recomend this site for everyone to look at it is blinkin fantastic!!!!! he may give you some pointers ive emailed the guy myself and he seems to be willing to help

[Pictus]

hmm sorry that wasnt meant to be a link it was meant to be a cut and paste job Sorry Robert :'( oh you may also notice the lack of anything chevy in the engine bay

[Happy Jim]

Originally Posted by Pictus

hmm sorry that wasnt meant to be a link it was meant to be a cut and paste job Sorry Robert :'( oh you may also notice the lack of anything chevy in the engine bay

Good site though, very impressive piece of work

[dbonner]

I agree with Myles, I think that a very good choice could be to build a frame that is as close as possible to the original with 2 big round tubes. I've noticed that the Haynes book on cobras has a very nice large format picture of a naked cobra frame, that photo alone (plus a few key dimensions) would almost do it.

However here's another idea. I've been looking at the XJ40 suspension design and I've realised that their entire rear subframe is a thing of beauty. The front end is not bad either. Why not build a spaceframe to recieve the complete front & rear subframes from the XJ40? This would reduce enormously the work in jigging the pivots for the A-arms, and the geometry built in by jaguar is likely not so far off the mark. OK, so the XJ40 is wide, but you can make a body to cover just about anything. By the way the subframe that's really a lovely design is the rear, so you might want to use that one complete and throw out the front crossmember. A plus to this approach is that, if you do it combined with a mega stiff backbone, you can end out with a car that has extremely luxurious manners (road noise filtering)

[dinosoar]

I have been muling over the idea of what other types of more modern running gear may suit.
I had a thought the other day about using Subaru Impreza rear. There must be loads of afterm market stuff around for these and they regularly get stuffed into the scenery.
Just a thought....What think you all?

[dbonner]

The real challenge is finding a single donor that can supply a large proportion of the parts. That's obviously what's appealing about the jaguars - all of the suspension front & rear can be reused in same configuration as original. In the case of the Impreza, could you tell me if the front end has double wishbones or struts? If it has double wishbones then you could just throw out the front wheel driveshafts & engine/transmission and keep all the rest, and it might be a pretty nice package.

[white.whale]

If you are living in Switzerland and seriously looking for a jag based suspension I have a complete donor car in running condition. It is an 86 XJ6 with the 4.2 litre engine and
is my current driver in Paris. If you have 500 euros and the time to drive it home you are then at least 25% of the way to getting well started. It's not the prettiest car in the world
but as its the last of the series III's its going to be pretty easy to refurbish to cobra standards. You can also use the handbrake and steering and lots of other bits.

[cobradreamer]

I build my own chassis for my lotus seven replica. This was a space frame chassis, and not a ladder frame as used on the original cobra's. Personally i am more a fan of the space frame chassis's, as they have a much better kg's to torsional stiffness ratio.

It wasn't a very difficult job i found, it took about 25 hours of cutting, filing and welding, i used the same methods as RichC discribed.

There are pro's and con's to building your own frame. Most of them have been posted about by others so i won't go into them in great detail. But i feel that i must say that unless you feel that you have the skills and abilites to do the job to a high standard it may be better in the long run to buy one ready made.

Personally i would go for buying a tried and tested ready made chassis for my cobra rep when i start the build. As time is a factor for me, also my MIG welder is only a 150 Amp one, it was ok for my lotus chassis, weighing only 500 kg's dry, only a 1600cc 150 BHP engine i feel that it is fine, but i would want one with more grunt to make a chassis for anything with a more brutal engine. Also the sell on cost is some thing that is inportent to me for my cobra rep when i start it, but not with the lotus rep. I have spent over 150 hours building the lotus rep, spent £1,250 so far, and it will probably be worth about £1,500 when i finish it.

Four books which i found very handy are.

How to build you own sports car for as little £250 - and race it! by Ron Champion (this is the one i based my car on).

How to build your own tiger avon sports car for the road and track. by jim Dudley (this is the one i wish i had based my car on).

Race car chassis design and construction, by Forbes Aird.

Chassis Engineering, Chassis Design, Building and tuning for high performance handling. By Herb Adams.

Both of the last two are American books, but converting the imperial into metric isn't to difficult. All for books i got from Amazon.

Good luck with what ever you decide on doing.

Dom