Looking for more real world feedback on C4 conversions

[55 Rescue Dog]

I have no idea how many C4 tri fives are out there, but I would really love to hear more real world feed back as to how great, not so great of a set-up it is? So far I have committed to a $3000 55, and $2000 C4 suspension. Ready to move on step 3, getting a conversion chassis. CED first choice. Just need to hear more from people that have actually driven them, or any others. I realize every set-up, or expectation is different. I just want to do it right. I want the best driving, handling 55 possible with the least issues.

[WagonCrazy]

I have made the committment on my 57 Nomad, but (sadly) have not gotten it completely roadworthy just yet.
I think you'll be pleased with handling.
I have another 57 wagon with conventional suspension and it handles like....well...a 50's era tank.

On the Nomad build, I started out thinking I would use the stock Corvette batwing springs (front and rear) but changed my mind and went with a set of ViKing double adjustable coilovers. I wanted to be able to better tune the ride height, compression and rebound dampening, spring weight, etc.

I think you'll be pleased with yours. Keep going with the parts assembly...

[chevynut]

RD, there are literally hundreds of these cars running around so it's a popular conversion. I think Newman has done around 500 or more of them since he started, every one of them with the stock C4 springs. There's also been a ton of C1, C2, and C3 Corvettes outfitted with C4 suspensions, as well as first-gen Camaros.

Wish I could tell you where to go to drive one of mine, but they're all too far away from you as far as I know. I'll bet there's some C4 tri5s in your area though, if you asked around. The best I could do is give you some phone numbers as I've offered before. What I recommend is that you to go drive a couple of C4 Corvettes...one early and one late. A tri5 with a C4 suspension and stock springs is going to drive similarly. The CG may be a bit higher but it should feel close to the same as far as road feel. It will give you a good idea what to expect.

To be honest with you I think you're asking for something you're not going to get. How is someone going to convey their feedback to you other than to say "I love it" or "I hate it" or "it handles great"? What does that mean to you? The only way, imo, that you're going to get your question answered for yourself and what you're looking for in a car is to drive one yourself. BTW, I have yet to hear anyone say anything negative about their C4 conversions, no matter who built them.

Maybe you should fly to California and drive Newman's 57 wagon . I had a friend do that after sinking thousands into his 57 front end, and he was instantly sold on it...so we installed a C4 front suspension in his car.

[55 Rescue Dog]

I have convinced myself that the C4 is the way to go, but as you being a chassis builder, I can't help but wonder, and want to know...how many have you personally driven, and tested with all the different combinations, is what I'm looking for? HELP ME

[chevynut]

RD, I regret to admit that I have not yet driven a tri5 with a C4 suspension . I realize that having done over 60 projects now, that sounds kind of weird. However, I got into this hobby-turned-business quite by "accident" and demand from customers. I did the conversion design and built my frame jig solely to build my own conversion chassis for my Nomad. When I started showing my progress on forums years ago I got calls and e-mails from guys asking me to build them a frame, so I did. One after another I got requests to build them and I did it part-time along with my regular engineering job. I retired a little over 3 years ago and the orders were still coming in, so I decided to turn it into a "legit" part-time business. I set up my website and we're still building them. I honestly don't know how much longer I'm going to do it but for now I have no plans to stop anytime soon.

Even if my Nomad was running and driving, I don't know what I could tell you that would address your questions. If I had driven a dozen of them and tested BBCs versus SBSs, automatics versus manuals, coilovers versus stock shocks, sedans versus wagons, early versus late suspensions, what is it you'd want to know? What if I said all of them are great and a huge improvement over stock? Sorry but I really am struggling with what you're asking for as far as feedback.

All I can tell you is the feedback I've received from customers has been very positive. One guy built a 57 for his dad as a daily driver (in NJ) and he said the car "drives like it's on rails". Another (the blue Nomad in WV)) told me his drove like a modern car instead of a 50's car. Another (the silver and white 55 in Utah) told me his was "the funnest car I've ever driven". I thought I was going to get to ride/drive in the 55 a few years ago when I was at SEMA in Vegas, but we never got together. The owner was at a car show an hour or so out of Vegas. I don't know how many of my customers actually have running cars. Most of my customers are home-builders, not shops, though I have built a few for shops. I have seen several tri5s at local Goodguys events with C4 suspensions but have never asked the owners for a ride. Maybe I should.

I don't know what else to tell you. Kyle Newman was kicking butt in autocross against Camaros and Mustangs with his 55 and their 57 wagon when he was racing. To me that's proof of the performance aspects of the suspensions. Super Chevy did a test of Newman's 57 wagon a few years ago and it out-performed the 5th generation Camaro (2010). I still have that article somewhere. I don't know what else you're looking for, and as I said I don't think anyone can tell you. To me your question is kind of like asking for someone's feedback on a girl.....what's the question? Is it if she's cute? Sexy? Smart? Fat? Funny? And everyone has different tastes. There's nothing like first-hand experience, and I'd recommend you look for one to drive yourself.

If you have specific questions, I can try to answer them. But to just ask for "feedback" is pretty vague. I can give you technical specs if that helps.

[55 Rescue Dog]

I appreciate your responses, and sorry I can't be more specific. I realize that any chassis design will have different characteristics, and it is like trying to pick out shoes for someone else. Until you try them on, you just don't know. Just didn't know, other than making all the components fit, I was looking for what R & D testing was done on a chassis to make it handle the best, with nothing breaking. Oval track chassis builders never seem to build the same chassis twice. They are always tweaking something. Small changes in the design can make a big difference with testing. The tube frame Camaro I built, with no engineering drives/handles pretty good to me, but maybe no one else, and if I had to do it over, I would have made some changes, but had no idea how it was going to work until I drove it. I have been avoiding autocrossing it because I don't want to know what else I should have designed different that I can't redo. Just want a chassis that has been well sorted out, cost effective, and rock solid dependable.

[rockytopper R.I.P 5-13-2017]

Dog just about all trifives street driven that have competed in any form of Racing use C4 setups. In your budget range your not going to find anything better. I believe my bolt on setup is going to get me close to what the c4 cars are doing but certainly want better it. Even with C4 there are tons of tuning options if you want to get serious I guess. Think spring rates you choose may play into. Rat Rod Russell who offer the DIY C4 frame have competed in AX. You might pick his brain to see what seems to work best etc... The best racing rate might not be to friendly on the street all depends on what you want I guess.

[chevynut]

RD, as I have said before, my conversions maintain the stock C4 suspension geometry. I don't narrow anything unless requested by the customer and then only do it in the rear. That's why I suggested to go drive a C4 corvette if you can't find a C4 tri5. There's really nothing different between my conversion and Newman's or RR Russell's as far as geometry. I have noticed Russell's suspension installations in the past seem to make the car sit higher than it needs to, especially in the rear. I don't know what k-member height relative to the frame either one of them uses. When set up properly, the lower a-arm should be level or slightly down at the balljoint end, and the same with the halfshafts. I set the rear with halfshafts level in my jig and the batwing is as high as you can go without notching the frame.

Here's a recommendation for you. "Jims57" on the other site has a Newman chassis and he's been driving his car for a couple of years or more. You should ask him for his opinions and feedback on it. He's a self-proclaimed liberal so he doesn't like it here with all of us conservatives and racists. His k-member bolts into the frame and I don't know what ride height his is built to. Newman's frames don't allow for coilovers, at least in front, so he is using the stock C4 springs.

I don't think anyone here has ridden in or driven a C4 conversion tri5. Mick (bowtiedownunder), Steve (Bluegrasstrifive), and Brian (Custer55), Paul (wagoncrazy), Mike (Fladiver64), and Arend (Willawog) are all still building theirs as I am. The last 3 are my customers.

[chevynut]

Rocky, good post. I'm not sure what all you can do to "tune" the C4 suspension, but certainly spring rates and shock tuning can be done. The pickup points for the suspension could be changed by modifying the rear camber brackets to change rear roll center or designing the dogbone attachment so you have multiple holes to use for anti-squat. You could also further lengthen the front spindle with longer balljoints if you wanted to, I suppose. But none of those changes (except the dogbone adjustability) affect the construction of the frame.

I'm personally not a fan of bolt-in k-members in these chassis. If you look at the C4 Corvette chassis there are 4 diagonal braces from the k-member to the frame to support it, two in the front and two in the rear. None of the bolt-in k-member chassis for tri5s that I've seen use those braces or any other bracing. I think the weld-in k-member looks better and actually looks like part of the frame. Personal preference I guess.

[Custer55]

Rescue Dog, I have not driven mine yet (I hope to have it far enough along to test drive it by this spring) but we own a 90 Corvette which I drive a few times a year. The C4 Corvette has excellent handling and a nice tight feel. Like most people I'll probably never push it anywhere close to it limits. (maybe 75% to 85% of what it can do) It can go around a 30 mph off ramp at 65 to 70 mph without a problem. As far as ride quality it is pretty good on a smooth road, but you will feel every bump in the road. Tires also have a big impact on the ride. When we replaced the original Goodyears with a set of Falken FK 452's the ride was much better, night and day difference. I'm sure shocks can make a big difference also.
Hope this helps.
Brian