tjZ06

NOT coil overs, but aftermarket leaf springs.

Which ones are you running?

Do you street drive the car still, if so how is the ride?

What shock did you pair them with?

AutoX or Road Race (or both)?

Any feedback is greatly appreciated.

-TJ

Bink

VBPs - Front~ 1200#
Rear~ 900#
(roughly...I can never remember the exact #s)

Bilstein Shocks revalved by Bilstein for the VBP springs

T1 swaybars.
Solid, tight ride. Not a daily driver but fun to drive. I sit in a Sparco Evo seat sans padding...so the ride can't be too bad.

I've done a little Autox and HPDE. No racing.

LehmanZ06

I actually don't think the stock springs (I have an 04, Run in ASP), should be changed---

But if you go to a much bigger front tire than stock, say 315 on a 10.5" wheel---then you should upgrade shocks IMHO----I got Koni singles from Sam Strano stranparts.com----

Eventhough I run the highest Z06 in the land---it's pretty quick, and getting quicker all the time.

Team "Itchy *****"

John Shiels

same here I could drive NY to CA no problem in my Kirkey seat.

AU N EGL

Lots of guys run the T1 springs

vms4evr

Have you looked at the spec for the spring rate for the C5 Z06 then the C5 T1 springs. It's like 75lb/front and 50lbs/rear more for the T1. Almost seems like it is not worth the effort of swapping on a Z06. Then again I could be way off base...

gkmccready

More interesting is that VBP recommends rates with front > rear, but Chevys springs are all front < rear.

* C5 Z06: 526# Front, 714# Rear
* T1 (C5): 582# Front, 793# Rear
* C6 Base: 420# Front, 657# Rear (VBP: 400-420 F / 600-620 R)
* C6 Z51: 526# Front, 645# Rear
* C6 Z06: 531# Front, 782# Rear
* T1 (C6): 582# Front, 850# Rear
* Hyperco HPS (Street): 565# Front (12405HPS), #765 Rear (12406HPS) $521ea
* Hyperco HPT (Track/Solo): 625# Front (12407HPT), #850 Rear (12408HPT) $521ea
* VBP Sport 990# Front, 650# Rear $500ea
* VBP Extreme 1050# Front, 855# Rear $500ea

AU N EGL

Many ppl just put on the T1 sway bars with 04 Z06 shocks and springs and go from there.

If I was going to change springs, I would just go to coil overs like LG has or Pfadft has and be done with it.

vms4evr

That's my present setup and I like it a lot. And really easy to convert back if I want to. Not bad on the street either, other than the rattling of the end links...

I agree. If I was going to go to that much trouble I'd forgo the transverse leaf springs and put on Pfadts. For the price it is hard to resist.

tjZ06

FWIW I run 315/30-18 and 335/30-18 Hoosier A6s and run on a VERY grippy, large (maybe huge is correct) concrete lot.

I always did wonder about VBP switching the spring bias. Hmm.

-TJ

Diesel68

It is interesting you say that. I have a feeling that VBP measures their front spring rates differently than GM. I had a set of their springs for my C4, and I loved them. Front rates measured 1366# and rear at 435#, but I could not tell that they were that stiff on the street. They actually worked very well for the street and autocross. I had Koni singles and with soft rear rebound adjustment, it handled road imperfections very nicely. It was a very fast set up as well, and had very little body roll.

Obviously C4 and C5 rates do not correspond well. For an autocross car, I am not sold that different springs are needed. Especially considering that most surfaces are slick asphalt locations. For an open track though, I think springs would probably help a lot. I only have a 35mm front bar with stock 04 shocks, and I felt my Z06 had a lot of roll on the faster sweepers. With new springs, I would be able to get the car lower with out bottoming out, and reduce body roll at the same time. A lowered car can typically also dial in more negative camber. I am not sure what shocks to run, but there is a solution out there to help damping, but also maintain ride comfort. I would stay away from Bilsteins or any non adjustable shock as I have found that they typically sacrifice comfort for performance.

I am not sold on coilovers. I am sure they perform well, but I have not had any problems with leaf springs, and I like to work with a system as close to OEM as possible to eliminate any unexpected problems. VBP has a proven system and can make any custom rate spring you want, and at a decent price. I am just just throwing something out there to think about.

tjZ06

Right now I'm on factory '04s (car is an '02 though). I'm not sold on C/O's yet either... hense this thread. If I stay leaf spring I'll probably go VBP, just not sure how "extreme" yet. I'll put Penskes on the car, again just not sure how extreme (single, double, tripple adj, remote reservoir or not etc) for those either. So many options.... so much $ to spend. Haha.

-TJ

Diesel68

I started my reply before you posted yours. :o

One of the sites I run on is also a grippy concrete surface. A surface like that can really use the spring. But that is a local event, and I am thinking about being competitive on a national level. The Solo Nationals and most tours are on slick asphalt.

When I finally upgrade springs, I am probably going to go fairly heavy with the front spring, but try to get a rear spring that is just soft enough that the rear end won't bottom out when lowered. It's a combo that worked really well for the C4 and I don't see why it wouldn't with the C5. I will probably go Koni's for shocks. I would rather get close enough and depend more on the driver than spend every nickel I have to get that extra tenth of performance.

gkmccready

The VBP numbers in the brackets are what VBP measured the stock springs at on their machines. So you can see the variation and get some idea of how the rates compare.

Bink

I followed John Shiels' advice on my setup (see above ). I researched what others had said in various threads- here. There were many who had moved up to greater and greater rates for the front springs especially. I don't regret it.
After I get the polys installed (and see how this improves feedback) I might try a stiffer front spring?

Bink

Wouldn't turn-in (autox) be better with VBP bias....?......seems like it would be easier to rotate?

Just asking..I'm a (relative) newbie.

John Shiels

My friend Alan did the same setup and loves it. Can't believe how easy it is to drive the car now and he has near 600 RWHP.

Oyishdog

I run the full T1 setup and love it...Honestly, I cannot imagine the car being any more balanced and flat feeling. I guess coil overs could be better, but a stiffer suspension might not lead to better performance. As it was sold to me, GM has dollars and hours spent in developing the T1 suspension for the c5, so the question really is, what not use it??

tjZ06

Which setup?

But is that road race or AutoX? AutoX is my goal, I'll still track day the car but that's for fun, not tenths of a second and points. RR is soooooooooo different. I've RRed and AXed my car... and it loves BOTH T1 bars for RR, but using the back T1 bar for AX makes it terrible. GM didn't test the T1 stuff for AX on super sticky concrete on 315 front and 335 rear Hoosier A6s.

-TJ

John Shiels

near the same as Bink and I for RR not AX.