k wright

I've read many threads on the use of aftermarket leaf springs VS coil overs and would appreciate current recommendations for spring rates on a track car (VIR & NCM based). The car is also street driven.

I really like the design of the leaf springs that are on my '08 Z06 but they are very soft.

Also appreciate shock recommendations.

crimlwC6

I race on my stock leaf springs and drm bilsteins. I run faster than guys with 5k suspensions. I'm not saying I'm the cat's *** but that the stock system is extremely capable.

crimlwC6

Do you aftermarket sway bars?

CHJ In Virginia

Keep the stock springs unless you are going to go with coilovers. Get a good set of Bilstein HD shocks and take a step up in sway bar stiffness. With a proper alignment and tires, it will be a long time before you can drive up to the cars new capabilities.

JeremyGSU

This.

SouthernSon

The shifting of weight allowed by the stock suspension is not that bad. It also allows one to get a feel for the results of inputs to the vehicle in varying conditions. Once you have learned to get the results of the various inputs at speed that you desire, you may want to stiffen up the springs/sway bars and get better one way adjustable shocks to elevate to the next step in track day events. Of course, when you reach this point, you will, more than likely, be desiring a dedicated track car. It sort of comes together that way.

Bill Dearborn

My thoughts are that if I did anything to the springs on my 08Z I would soften the rear spring since it seems to be too stiff. In bumpy turns the stiff spring keeps the wheels bouncing which means you can't get to full power quick enough exiting a turn. The DRM tuned shocks helped but there can only do so much.

Bill

MUKAK

i think the DRM bilsteins make all the diff... was bored the other day and swapped my DRM shocks for stock 06 Z shocks and its nite and day

my next move would be LG coilovers

dp201

I have the DRM Bilsteins also, and they've made a good bit of difference. Everything else is stock. Trying now to determine if upgrading the sway bars would improve HPDE performance and what ones to mate with the DRMs.

JeremyGSU

Yes, it would. I started off with my '04 C5Z with Bilstein shocks (previous owner already had them on) and just lowered on bolts with a track alignment.

I then added the Johnny O'Connell stage 1 package. After awhile I felt that the O'Connell shocks were a bit soft so I switched to DRM. Definitely noticed an improvement.

If I were in your shoes I would get T1 bars. With sway bars you will notice increased performance for sure.

VGLNTE1

Coil overs are probably the best mod I've done. Guys that say they can destroy the world with their leaf springs are just out driving the others. If they had a better suspension, they would go even quicker.

lefrog

For me the big difference going with coilovers was to eliminate the crosstalk in the leaf springs on bumpy surfaces. It made a huge difference. If you want to go the leaf spring route, keep your stock one, it's plenty capable. As other mentioned, tweak your shocks and swaybar instead.
Otherwise grab a set of LG coilovers, they are great.

fatbillybob

I think part of the problem is no one really has tested verified the different leafspring rates. Who has that testor? Gm made compromises to give us the t1 springs etc. Then we listen to people who claim to know and like sheep buy coils etc. With little more than emperical testing. After paying 2000 bucks your mind tells you it was better even if it isn't. Then we have "felt" seat of the pants improvement rarely if ever back to back tested on track with a driver who can do consistent enough laptimes to show an improvement. Add in so many other driver and chassis setup variables and getting any real data would cost more than the coilovers! So we racers trust and hope and are often disappointed. Too many times a softer stock setup is faster than a stiff flat handling car that only feels faster. Mind your wallets. Spend your money on driver improvement and only on mods you can guarantee will shave seconds like a new set of tires.

fatbillybob

what does crosstalk feel like? Do you define it as the corvette hop?

hklvette

Leaf spring rates: Hyperco has or had a tester, but I don't think they have used it to compile a list of spring rates from various stock leaves.

As for stiffer-than-stock setups. I think the factory puts a lot of time in to make sure that all of the components work together well. I've observed that most people don't keep that in mind when mucking about with the suspension. For instance, changing just the spring rate also affects roll-rate. If you alter one without paying attention to the other, you may get unexpected results.

VGLNTE1

It means when one side reacts to an abrupt road surface, the opposite side will react as well. Eliminating the leafs and running independent coils cancels this out.

hklvette

so what does the sway bar do when this happens?

VGLNTE1

I think the end links absorb that talk between without upsetting the feel. That's what I experience anyway. I also use big T1 bars. When I had my coilovers made I also told LG what sways I had, aero, tires, tracks I run, ect....

SouthernSon

I'm following you here. I think the sways are probably 98% of the 'crosstalk', if not more.

fatbillybob

yeah corvette hop. ... i think that when what you describe happens their is too much wheel rate. You have to soften up and or control that with something else like sway and shock. There is no question co is easier but T1 racers have proven the capability of near stock corvettes with leaf springs. The leaf is a good design. That's why you hear so many running great laptimes on leafs. Both are just springs. The wheel rate is either right of wrong for the application. Even if there is uncomfortable hop that does not always equal poorer laptime. If fact you could easily have the reverse.