The big advantage to the C5 frame is it's hydroformed.
(copied text)
Ted Robertson, chief engineer for the Chevrolet SSR said: "A traditional stamped frame with this amount of strength and rigidity would weigh roughly 20% more than this one. That strength allows the frame to take on the road inputs, which lets the suspension do its job precisely."

Hydroforming is a process of shaping steel tubes through the application of water at extremely high pressure. It replaces traditional stamping processes, preserving more of the steel's strength and stiffness as it goes through the forming process. Hydroforming is done at low temperatures to retain the material's strength throughout the forming process, unlike high temperature processes which decrease material strength.

 

that is the solution that i came up with also. i've spent several hours lying on my back staring up at that floorboard trying to figure out how to shoehorn that 'spine' in there. now if someone wanted to get really bold and split a c-3 down the middle and widen it by about 4-6", we'd have something to work with :rolleyes:

 

crazyhorse, although i agree with your basic statement the hydroformed frame produces a lighter frame than a comparable conventional frame, i don't necessarily attribute the c-5 chassis advantages to the hydroforming process. rather the improvement in chassis stiffness was a result of a different design philosophy, as burners stated, switching to the central spine concept and away from the boxed ladder (conventional) frame.

 

[QUOTE]The VB&P shock tower bar made me think of how I could strengthen my frame and keep my motor from ripping loose the motor mounts. To handle the horsepower I'm going with a different approach. I plan on using motor & transmission plates with solid motor mounts in the stock locations. For the rear the 4 point Jegs roll bar will "be like Mikes" :thumbs: This would hold the motor in the frame and strengthen the frame at several points. I made the motor plates from .250" aluminum. The plates will also serve as a bracket for my remote reservoir power steering pump. Here is a pic of the motor plates so far. 2" steel tabs welded to the frame rails on each side and then bolted to the plates. The transmission plates are still on the drawing board but I plan to use .250" aluminum as well around the bell housing. Since I'm removing the T-Bar I'll need the frame to be as strong as possible… :crazy:

Hey Stingraycrazy can you open up another post and post up more pictures of your project? That looks SWEET!

Anyway, I've built my share of race-cars and if you have a problem with the frame tweaking than we "welded all the seams on the frame". I've seen my share of C-3 vette's and the spot-welds on the frame are nothing to smile at. Especially if your planning on driving the car like it was supposed to be driven then I would definately weld all the seams on the frame. If I remember correctly in the early 70's the racers would even weld gussets on the motor-mount brackets. :yesnod:

 

Some pictures of C5 frame:
http://www.corvettecavalry.com/techp...-c5-frame.html

Kind of hard to get C3 frame look like that :crazy:
How about building C3 body on C5 frame. :cool:

Even better pictures of C5 frame here:
http://data.corvette.co.uk:8080/ecar.../c5chassi.html


[Modified by Hemmo, 10:57 PM 12/11/2002]

 

Thank you for the complement! That means allot coming from VB&P. Have you been to my website? http://www.StingRayCrazy.com I have a chassis page linked to your site. I hope that’s ok? I just posted a new topic about motor & tranny plates for street use in the C3 forum. Do you think the motor and tranny plates would vibrate more than just the solid motor mounts? :crazy:

 

Stingraycrazy-Excellent web page. You do great work! The Corvette forum members really benefits from Corvette enthusiast like yourself.
Dan

 

Great Thread.

I am better at asking questions than I am at supplying answers. Many good points are being made and maybe we can learn from this brainstorming session.

I have looked at my old Chevy Power Book and reviewed how the roll cage is installed. The front or rear section I’m not really worried about, it’s the center. The way I see it the center is bridged with and 8 point cage. We will never be able to replace the structural strength it provides.



I wish I could get this spine in my tunnel I do think it would work, but How?

I can strengthen the front or the back, but how about the center? I think the X is definitely possible at least to some extent. I had wondered about a hidden cage that goes from the front door post hinges to the front bumper and from the back bumper to the main roll loop. But how can I tie them together through the door? Like someone above posted" Not even enough room for a cup holder."much less a roll cage in the passenger compartment on the street.

I thought about a rectangular Aluminum C Channel frame to go inside the door. One end attached to the upper and lower door hinges and the other end with a latch somewhat like the C-3 Convertible uses.

I considered using a piece of 1/4” Aluminum about 8” wide on both of the insides of the door forming a box to let the window operate. It would use however much lip space allowed to form a C-Channel on each plate.

I thought about this earlier in the thread when I was telling Stingray Crazy about the conversion kit for coupe to vert doors. The latch wouldn’t have to be in between the door and the pillar post like the Vert. It could stick out from the end of the door panel and mate with the female end extending from the Main Roll Loop at the rear side of the seat.

This is hard to describe. But all that would be exposed is the latch receiver at the rear of the door panel. It would probably only be a 1” in diameter and let the latch stick into the door maybe 2 ½ inches. The latch is round and tapers as it goes out. The door receiver is just the opposite. It would provide strength from any direction but out. The door striker could be supported by a side plate off of the Roll Loop to assist in retaining that. The weak spot then would be the door hinges or at least the bushings. Stainless Bushings?

Remember that no idea is a bad idea, because even a bad idea sometimes spurs the thought that creates the answer to a problem.

Thanks for all of your ideas. JIM





[Modified by PROSOUTH, 10:30 PM 12/11/2002]

 

I know. He gets really busy sometimes I guess. But it's worth the wait.
I've been on the phone with him with the scan tool in my lap, trying to figure out what's going on. Really good people. :blueangel:

 

I must say I'm absolutely amazed at the participation in this. It's this sort of thing I try to explain to people at work, who don't get while I'm so into my Vette. It's the people in the hobby - the comraderie and knowledge shared. I myself have become a little less interested in trophies over the years, and a lot more interested in sharing ideas, and talking to people's kids at shows that want to get a picture with the car - and remind me of when I first caught the fever.

Anyway - I like this other concept of getting the front and back halves tied together via the door beam- I think it would have a similar affect as the 8-point. I've gotten so obsessed with this that when I'm driving to work in the morning, I sometimes go down the road with two fingers stuck next to a t-top guide pin at the center bar, to try and determine the direction of movement. It does feel like it's both ways, but I'm not sure. I might even put some plumber's putty at certain locations when I get a chance, to try and record the movement. (I never intalled my upholstery on the tops, I simply gave them a good paint job. I prefer the light weight and extra overhead clearance) I think the other C-5 related points are right on the money as well - the goal is to produce a rigid platform that we can utilize suspension components that do not have to compensate for excessive movement in the chassis, that will result in more precise performance without the need for excessive spring rates, etc. Anyway - love this stuff - It'll get me through the winter I think.

Ray. :flag

 

Thanks for the nice words Dan. I'm just having fun... Have you ever thought of modifying your Shark bar to a roll bar combo, tying the body to the frame?

Gkull gave me a great Idea about a SFI flex plate shield and a tranny frame support. He suggested that I use an SFI shield for NHRA rules. I'll give it a try.

TPIShark I agree with you, this forum has given me so many good ideas. My wife thinks I'm nuts for sitting in front of the computer so much... Exchanging ideas and giving support to another member is worth it for me!

The Trans support will look something like this :crazy:

 

Where Can I find that VP Spreader Bar for the front end? I can't seem to find it anywhere. I want one.

 

http://www.vettebrakes.com There ya go :crazy:

 

Just click on our web-link and go to "Shop Online". Then scroll to the bottom of the page and click on "Shop Now" to view the complete catalog. Click on the top of the page on page number "28" and at the top of page 28 you'll see the Spreader-Bar kit.

Hey Stingraycrazy, the engine plates will vibrate the same as solid motor-mounts. A buddy of mine has a vega with the engine plates and it's just the same as the solid motor mounts another buddy of mine has in his nova. :D

 

I am partial to a spine type of reinforcement over door reinforcement. The reason is that I feel the frame should be structurally evaluated on it's own. The body provides little stiffening and I feel that efforts applied to it only reduce body flexing and rattling and contribute little to the frame's stiffness. I say this because the A and B pillars are little more than unsupported columns. They don't have any significant fore or aft bracing that would resist deflection. Any loads applied would essentially be transmitted to the fiberglass and cause cracking.

I can see an arrangement that uses an a-arm strut and bars that tie into the engine. Then a brace similar to clutchdust's at the bell housing with a spine that attaches to that brace and runs the length of the tunnel and ties into the rear end and frame. I think that would add quite a bit of stiffness.

 

as stated before, there is such a wealth of information and creative thinking here, it's amazing. i wouldn't be surprised if g.m. or others didn't occasionally monitor this stuff just to see what people are thinking (what better way to get free ideas?).
anyway, from our perspective, that being a car that not only has been produced but is now long out of production and most corporate engineering is over, we have to weight certain aspects. what i call "s**t to worth" ratio. so far all the ideas here good ideas but have varying degrees of benifit and/or practicality. for us guys who are doing this stuff on the weekends in our garages, we've got to figure out what will provide max benifit for minimal cost and fabrication/manufacturing. sure, ultimately a c-5 style reinforced center spine would be excellent, however, how the heck are we going to put one in a c-3? the idea of the door brace is likely less effective but certainly more feasable. motor plates are not only feasable but on the market now, they have a downside by introducing a great deal of vibration into the car which some may not be willing to deal with.
so in short, we need to keep thinking. i'm sure there is a solution out there, we just need to figure it out. after all, if we don't, who will?

 

Stingraycrazy-unfornate this won't be possible; my products specialize in bolt on applications without modifying your Vette.
Dan http://www.vetteworksonline.com

 

Well Dan, after I finish Crazy I plan on finding a nice 74 vert. and restore it to original condition. When I get started on that project I'll be calling you about that Shark Bar. It looks like a great product. :crazy:

 

BURNERS I am partial to a spine type of reinforcement over door reinforcement. The reason is that I feel the frame should be structurally evaluated on it's own. The body provides little stiffening .............. I say this because the A and B pillars are little more than unsupported columns. They don't have any significant fore or aft bracing ...... Any loads applied would essentially be transmitted to the fiberglass and cause cracking.

I agree, I even posted this earlier. However I did propose to support the front pillar post with the front section of a roll cage going from the front bumper mount to the pillar post and then support the pillar itself with an additional verticle bar. Same in the rear except the Loop would catch the back kicker supports and then tie in the striker on the rear pillar post. But I do agree and was only trying to come up with something, and it did / does have a possibility of working.

Burners- A brace similar to clutchdust's at the bell housing with a spine that attaches to that brace and runs the length of the tunnel and ties into the rear end and frame. I think that would add quite a bit of stiffness.

I agree again, except I would not tie to the bellhousing unless absolutely necessary. If I did it would be with a Poly mount like I described earlier for the '55 style mount.

Ultimately a C-5 style reinforced center spine would be excellent, however, how the heck are we going to put one in a C-3?

Why not the same way as the '85? Why couldn't I run a 3x3 lightweight DOM Tube from the front frame dogleg all of the way to the bacK?

I believe I could make a transition from the front frame dogleg to just past the bellhousing that would allow my 3" exhaust run throuh it , then run the 3" square tube along side of the exhaust all the way to the rear crossmember.

I have no Clutch Linkage or Transmission Linkage to interfere. I could use about a 30" trans-member for the TKO to mount to with a passageway on the bottom to let the pipes go by or through. Then put two supports on each side between the original frame and the new spine. This putting a structural support about every two feet from the front crossmember to the rear.

Whew........................would it? JIM

 

PROSOUTH, I completely agree. I apologize for not fully comprehending your previous posts, things can get confusing at times. I can understand the concern about vibration from tying into the bell housing and agree with you and clutchdust that an isolator of some sort would be ideal. I think a spine could be designed to fit in the tunnel (similar to what you proposed). If a narrow truss arrangement could be built using 1" or 3/4" tubing it could extend to the top of the tunnel, even with a 4 spd or auto transmission. Then tie into the transmission cross member and, finally, back to the rear of the frame. The important thing is to get a greater section width than the frame rails and to get that with the least amount of weight penalty.