acroy

I love leaf springs. The clever suspension design is part of what makes C5-C7 interesting.

The jumping side to side etc is another matter entirely poor shocks + runflats etc. People blame the poor leaf, which is actually fully awesome.

Wonder if I can retrofit a C8 with a leaf spring haha

Though I will never own a C8 if it doesn't have a manual

Bill Dearborn

Maybe the lateral movement isn't due to the springs but due to how your car is set up. Take your car to an alignment shop and have the rear toe adjusted. Too much positive toe (toe in) in the rear will cause lateral movement on bumpy roads. Had a C6Z with a lot of rear toe in for track stability. Couldn't drive it down the bumpy street I lived on due to back end jumping back and forth but once the toe was corrected to just a shade of toe in the movement stopped and the car could be driven easily over the bumps.

As for the leaf springs they seem to work very well on the Corvette producing one of the best handling cars available and that is proven by how many amateur drivers can drive them fast on track and actually pass and run away from the cars mentioned in the thread. My C7Z handles like a dream.

Bill

vndkshn

The lack of a real aftermarket of different rate springs is a real valid point, probably because only Corvette (to my knowledge) uses the system. I remember years ago putting a system on a C3 car that had a bracket system where you could change the pivot point (for lack of a better term) and that would change the spring rate. The further out on each side, the stiffer the spring rate, the further in, the softer. Worked very well, surprised I never saw more systems like it.

The one thing I do like about DOHC cam engines is revving the hell out of them, something hard to do with a cam-in-block and pushrod/rocker design at a reasonable cost with longevity in mind.

Poor C4... the first to have it front and rear.....

Warp Factor

Fantastic-handling car.

jefnvk

It is almost as if even though race cars and street cars look similar, their suspension needs to be vastly different for two vastly different uses or something....

acroy

sure sure, but other things make it un-interesting... to me.

84 4+3

And the only one that doesn't axle hop on launch... (again, entirely different setup and arguably better depending on what your intended use of the vehicle is too. C5 and up is more advanced by far though.)

vndkshn

But your statement indicates that you believe it was the first with the setup, when it wasn't.

vndkshn

Yeah, I think the C4 launches better, and the later ones turn better. Although I really liked the turn-in of the C4 cars. But that has nothing to do with the leaf spring itself. :-)

Foosh

With proper set up on MSRC shocks, there is no axle hop in the C7. For example, the DSC MSRC controller has an automatic launch control setting which softens the rear MSRC shocks when it senses WOT from a standing start. Not only is there no axle hop, there is much better hookup because of the better weight transfer to the rear wheels.

None of this has anything to do with the transverse leaf springs.

acroy

Splitting hairs - I stated leafs are part of what makes C5-C7 suspension design interesting. C5 suspension was a big step forward over C4 imho; plenty of other factors other than the leafs

84 4+3

With 30 years of improvement, there sure as hell should be. it worked surprisingly well for what it is and is still a very decent setup even by today's standards. It was a quantum leap from the C3.

But agreed, back to the topic at hand. Again, it's the suspension design itself vs the leaf causing the real problem. That pretty much was stated within the first ten posts. Just another derailed thread waiting to happen lol.

patentcad

One can only hope.

Zaro Tundov

Why aren't transverse composite leaf springs used on any supercars?

RapidC84B

The CADs have already confirmed coil-overs. Both have pros/cons. Been racing Corvettes for years on transverse monoleafs w/o issue. I always chuckle when people compare them to truck leaf springs or talk about how they don't let the suspension be independent; what do you think your swaybar does?

RapidC84B

The C5/6/7 has a unique construction with a full perimeter frame and two cradle/subframes. Most "supercars" are carbon tubs these days. Transverse leafs are very light, low center of gravity, and load the chassis through the cradles so you don't have to have stabilizing structure up top on the shock towers.

ArmchairArchitect

They are- C7 ZR1 which holds track records. Not to mention C7 Z06, C6 Z06 and ZR1, C5 Z06 which squash many (not all) other supercars on the track.

There are many pioneering technologies unique to the Corvette, some of which have been adopted by other supercars (magnetic ride shocks and HUD for example) and some of which haven't due to a variety of reasons (not fitting the architecture of the car etc.).

TrackAire

Everybody mentions the anti roll bar effect of the leaf spring. Corvettes with factory leafs also have anti roll bars from the factory. But does anybody here actually understand the physics of a anti roll bar, whether it is an actual roll bar or the way the leaf springs work in anti roll? I'm willing to be educated but here is what I see when I put a anti roll bar into action. Everybody claims it "increases the spring rate" and that it keeps body roll to a minimum. But in my experiments, here is what I found.

When you have an anti roll bar on the vehicle (lets say the front) and you turn "left", the right side of the car does not compress so one would assume that is increased spring rate. But what is actually happening is the anti roll bar is lifting the left inside tire to keep the car level. So while your vehicle isn't leaning over with body roll, you are essentially lifting the left front tire off the ground to counter act the upward movement of the right tire and the anti roll bar moving upward. This does have some positive effects....steering feels crisper, camber curves might be better, car doesn't feel like it will tip over, etc. But you've now removed your left wheel from the traction equation and putting a ton of weight on the right front tire, often overloading it and causing it to slide (or push which would technically be understeer). The same happens in the rear.....the anti roll bar effect overloads the outside tire, lifting the inside tire so you end up with oversteer.

The problem is you're removing some of your available traction, braking and acceleration from the inside tire since you're lifting it up lessening its traction potential....on a constant radius corner where you are under high G loads, you're now depending on only two tires instead of four to help keep the car on the road. The other poster said the car moves out laterally....I don't think he means that the parts are moving but the the car is skittish and literally slides off the road under load. This makes for a car that is very sketchy and unpredictable....not confidence inspiring at all. The other issue with the anti roll effect is it makes putting power down coming out of a corner much harder since you've essentially turned a rear wheel drive car with two tires into a one tire wonder. Ever notice all the complaints by pro drivers in magazine articles when testing the C7 Z06 and ZR1 platform that they can't put the power down coming out of corners or the car is twitchy at the limit? Again, not confidence inspiring.

Another issue with the anti roll bar is brake dive and squat under acceleration. I do not believe an anti roll bar helps in either of these important performance parameters. So the important question is, everybody claims that the leaf springs have an anti roll effect.....does it do this anti roll effect like a anti roll bar and does it create the issues I've listed above?? IMO, anti roll bars are used for final tuning of the suspension, to handle specific track conditions, etc. The only spring rate I want holding up my car is the coil, leaf or torsion (how every your car is set up).....With coilovers it is very easy to change and adjust the spring rate to match your requirements.

Regarding the cost difference of leafs versus coilovers, I'll bet that in quantities of 2500 plus leaf springs, I doubt if GM is paying more than $25.00 per leaf spring.

Caveat to reality: Lets face it, 99% of the people on this forum aren't fast race car drivers, rarely push their Vettes to the limit on the track and think a "spirited drive" on some canyon is high performance and maxing the car out. Most of us here would suck as professional race car drivers (me included). Any modern sports car that is now being made is above the capability of the 99% of Corvette owners as mentioned above.

So I'm all ears and willing to learn on why leaf springs and big anti roll bars are a plus under very high performance applications. I own cars with coilovers and a Vette that had leaf springs and now coilovers. My Vette is now 99% track toy for track days. I know I prefer the track performance of the coilovers over the leaf springs. Saying that leaf springs are superior to coilovers in every respect except cost is pure bullcrap. If anybody wants a ride in a Corvette C5 on coilovers with full monoball A-arms and compare them back to back with their stock Corvette, let me know. Drive my car then drive yours and tell me how dramatically different (better or worse or about the same) the ride is. Putting out a blatant statement that all coilovers will ride worse than leaf springs really is fake news. There is a very good reason why every high performance car manufacturer uses coilovers and none uses leafs. Facts are facts.

RapidC84B

A roll bar is just a torsion spring. You twist it in opposite directions and it increases your wheel rate. You move it same direction, like over a bump, it doesn't twist and has no effect on wheel rate. Leaf springs are great... light, low CG, and they load the chassis through the cradles removing the need for any shock tower reinforcement.

Leafs have no anti-roll effect... they're springs. The one side does not affect the other in a material fashion.

vndkshn

Well, I'd say in your example, really the anti-roll bars are doing BOTH at the same time. They are preventing the right from compressing (increasing spring rate) AND lifting the left side to reduce roll.

Your example is very correct however and highlights why anti-roll bars are generally the last/final tuning piece of the puzzle in the suspension (as you pointed out). I think the mistake many people make is sticking big bars on softly sprung (and weakly dampened) cars and that makes the lift you describe that much worse. I chuckle at the ones that brag about carrying the inside tire around a corner as some sort of badge of honor, I just see it as lost grip and speed.

I also don't correlate the leaf springs on Corvettes to anti-roll bars. The way they are mounted, there should be no transfer of energy from one side of the car to the other.

I'd also say that comparing just about any aftermarket suspension to a stock one (maybe with the exception of the mag ride stuff) in terms of just ride is a bit unfair, even if it is just swapping the leafs and stock shocks for coilovers. That said, are the shock mounts in a Corvette reinforced to handle the weight of the car (especially over bounces, etc)? I don't know, I've just seen several other cars swap to coils and then wonder why their shocks blow through the shock mount. But back to aftermarket versus stock, ride wise, just about any decent aftermarket coil setup will ride better just due to better valving in the shock (of course, some cheap setups could be worse). Factoring in mag ride setups, that could change of course.