Building a custom frame. What material to use?

**Last Ride** · 09-07-03, 10:45 AM

Okay, so I have been toying with the idea of having a custom frame built for my car to accept C4 suspension. Assuming they can make the frame out of ANY material, what would you choose and why? I was wondering if maybe an aluminum frame would have any benefit over a steel frame, for example. That way, I could fill the aluminum frame with foam for more rigidity and still be at the same weight of a steel frame. Any other thoughts or comments?

**MaineShark** · 09-07-03, 12:38 PM

Aluminum has a much lower fatigue life than steel. Fine for race cars, or professionally-engineered passenger cars, but if you aren't planning on inspecting and possibly/probably repairing or replacing the frame, I wouldn't even consider it.

There are several companies that will modify an existing frame to accept C4 (or C5, if you have the bucks) suspension/drivetrain. I think that would probably be the best way to go.

I'm suprised that no one makes a frame, from scratch, designed to take the newer suspension. Probably a liability/legality issue relating to "modification" versus "manufacture."

An ordinary steek frame is probably the best way to go. If you win the lottery, then maybe titanium

Joe

**Last Ride** · 09-07-03, 12:54 PM

Joe--
That's what I was afraid of. I knew there had to be a reasonthis hadn't been done before. I know there are companies out there that make/modify stock frames to accept a C4 (or even C5) suspension. Here is a guy that makes them from scratch: www.streetshopinc.com He said that doing the C5 suspension would need trimming of the floor in the rear, and that didn't sound too appealing. I am also talking with a local place that can do the same thing, probably even a little cheaper. I was just collecting ideas. Thanks for the post!

Bryan

**patsnitrovette** · 09-07-03, 02:33 PM

These people build a tubed frame and you can run either c4 or c5 suspension.
philadelphia motorsports corporation-1-215-333-3062
if you were at carlisle you wouldve seen a rolling chassis and a complete vette there.very nice work.

**richscorvettes** · 09-07-03, 02:46 PM

Bryan,

Here is a link to information that Charles Berkhart has assembled that lists many, if not all, of the known shops that either convert stock frames or make new ones. Some of them are tubular frames. Most seem to focus on the C1 or C2 cars but there are a couple that handle C3's including Philadelphia Motorsports and Car Creations. I've seen virtually all of them in person and personally like the design and engineering from Car Creations. He will convert a stock C3 frame to accept C4 suspension.

I did see the Phila. Motorsport prototype tube frame at Carlisle, and their first completed C3, which used C5 components. I'd like to see how it performs in real life driving. It does require an entire new floor in order to clear the C5 driveline so there is quite a bit of body modification necessary to make it fit. Converting to a C4 setup is involved from a chassis perspective but doesn't require as many body mods.

Good luck on your search.

Rich Lagasse

**Last Ride** · 09-07-03, 05:58 PM

Originally posted by richscorvettes
Bryan,

Here is a link to information that Charles Berkhart has assembled that lists many, if not all, of the known shops that either convert stock frames or make new ones. Some of them are tubular frames. Most seem to focus on the C1 or C2 cars but there are a couple that handle C3's including Philadelphia Motorsports and Car Creations. I've seen virtually all of them in person and personally like the design and engineering from Car Creations. He will convert a stock C3 frame to accept C4 suspension.

I did see the Phila. Motorsport prototype tube frame at Carlisle, and their first completed C3, which used C5 components. I'd like to see how it performs in real life driving. It does require an entire new floor in order to clear the C5 driveline so there is quite a bit of body modification necessary to make it fit. Converting to a C4 setup is involved from a chassis perspective but doesn't require as many body mods.

Good luck on your search.

Rich Lagasse

Rich--
Where's that link? We have spoken before, and I have spoken personally with Paul Newman. There is still no doubt in my mind that Car Creations does top notch work. My biggest problem would be the cost associated with Car Creations in the face of other options. For what it would cost me for a CC Conversion, I could have a new frame built by a competitor and not have to worry about the downtime or the other little "necessities" associated with the CC Conversion (ie, sandblasting and powdercoating frame.) Most of these places are also closer to me. I have toyed with the idea of locating a second frame for my car and shipping that out to Newman for the work, but again, it quickly gets to be quite a bit more expensive than the other options. I guess you could say that a CC Conversion would be a piece of mind, but I am trying to see if the quality of the other products out there even compare to a proven product. If so, and I can get them at a less expensive price, then I will go that route. Thanks for taking the time to respond. The car looks great!

Bryan

**taracatac** · 09-07-03, 06:40 PM

If you have tons of money, check this out:www.retrovette.com
They will take any gen Vette and mod it with a C4 or C5 frame/internals/interior. They have several price points/options, but it is $$$$$!

**richscorvettes** · 09-07-03, 07:05 PM

Byran,

Here's that link I mentioned in the earlier post. After shutting the system down I realized that I hadn't included it and just came back to do that when I saw your post. Here it is: http://www.carols62.com/ There are direct links to most of these builders with information about their products that Charles Bernhardt has assembled. By the way, he built his own from scratch.

I went through much the same research as you are doing in considering the options out there, however, several more players have gotten into the conversion business since we built our last car. Many were at Carlisle this year and last and I had a chance to look at several. Having been through building one, there is a lot to be said for a supplier who has a well designed and built conversion and that has been well sorted. That's not to say that some of the newer outfits don't have products that will work well but it's likely that there will be some additional trial and error involved that won't appear until you get into it. But, that can also be part of the fun in building one and there are more ways than ever to approach a project like this.

Good luck with the search. Let us know which direction you take.

Rich Lagasse

**Last Ride** · 09-07-03, 08:40 PM

Rich--
Thanks for the link. Most of it relates to C1-C2, but some are very interesting and informative nonetheless. I am sure something can be done to adapt the C2-style to the C3, but who knows? Anyway, I have already dealt with one of the places mentioned on the list, and I would NEVER EVER even for a second think about letting that man touch my car again. He may do some pretty cool things, but he royally screwed up my car, took the money for it, then did nothing to make it right. Anyway, thanks again for the link. I will contact some of the others on that list.

**groovyjay** · 09-08-03, 04:06 PM

If I was to design my own frame I would use titanium, BUT now that we all know how much that stuff costs, I would go with chrome moly steel and honeycomb structured aluminum frame, it would still be VERY light, yet VERY strong.

**Last Ride** · 09-08-03, 04:44 PM

I spoke with a local custom shop that is willing to try and tackle my application. Their main specialty is frame and suspension work, and they are also qualified to service and perform warranty work for Lingenfelter. We spoke at length today about what I was wanting to do, and the direction I was planning to take with the car. We explored websites of others offering similar conversions, etc. When I left, I had a very good feeling about the place. He promised to research my needs on the internet and get back with me. Overall, I think it will be an interesting winter. You gotta love walking into a shop and seeing a Twin Turbo Lingenfelter C5 and a Magnuson Z06! Jay-- Chromoly Steel sounds great! I wonder how much it would actually cost to do a frame in Titanium.?.?. Here is the frame style that most got my attention:

Bryan

**MaineShark** · 09-09-03, 09:51 PM

Chrome-moly steel is good stuff. A couple caveats, though: you need to TIG weld it, and it needs to be stress-relieved after welding (basically, you put the whole frame in a big oven and bake it at a certain temperature for a certain amount of time, to allow the weld stress to relax).

Good stuff, though.

Also remember: pipe is dimensioned from the inside, with the wall thickness added to that; tubing is dimensioned from the outside, with the wall thickness extending inward. You want tubing, not pipe, or you'll have trouble making things fit...

Joe