C5_Z06

Hi,

First of all im new to the forum but I've been hanging around here searching all old old threas for a while. Great information source. especially since the Z06 is quite a rare animal where I live (Scandinavia). Unfortunately I haven't found the answers to all my suspension questions, hence this thread. I hope you all can guide me in the right direction.

My car ia an 2002 Z06. For now all stock with 29000 miles. I bought tha car a while back to have it as a weekend car / track day car. I.e it's not a daily driver. Up til now I've attended some track events, that is road corse tracks, and I'm quite surprised that the car handled that well being all stock. My impression of the car was that the grip was quite good but the chassis felt soft and unresponsive compared to my previous cars (European cars). The stock Good Year Supercar tires was ok for a while until they overheated and became slippery. Power was quite good though, having all that torque makes it easy to drive and modulate the power. I'm more than happy with the power train.

My goal is to make the car more responsive and direct in it's behavior. E.g I wan't to have a better feel of the car, it feels to soft/sluggish now, and that makes it hard to drive it on the limit. I've looked into what's available and would like to keep the mono springs and not go to coil overs. Mainaly because I don't want to "slam" the car and I'm a bit concerned that the shock mounting are not designed to take also the weight of the car. Some tracks I attend have uneven surface (e.g like Nürburgring) so I like to have proper suspension travel retained and a decent ground clearance. I have no problem with the suspension being hard and uncomfortable.

The obvious choice is the complete T1 kit.
Pros: GM-enginered. Made to work together.
Cons: Made for SCCA T1 class, that is being limited by their rules. A bit old, but perhaps that's not a bad thing. A bit expensive. No adjustments possible.

Other alternativre would be for instance Koni FSD shocks, Hyperco or VBP springs with track spring rates, Pfadt swaybars. VBP poly bushings.
Pros: A bir cheaper compared to the T1 kit. Newer design. Shocks adjustable, swaybar adjustable. Shocks rebuildable.

It would be great to get some input to the chocies above. I found some info here: http://forums.corvetteforum.com/c5-g...or-the-c5.html

Some questions then:

* How do the FSD's compare to the T1 shocks, high (damper)speed vs low speed performance? Compression and return damping? Quality? Koni also make Sport shocks, how do they compare to the FSD? Are the FSD comfort oriented?

* T1 vs VBP vs Hyperco springs. The spring rates are mentioned in the link above so they can be compared. How do the FSD work with the higher rate springs? Obviosly the T1 shocks are tailored to the T1 springs so that shouldn't be an issue I guess.

* Ride height, T1 seems to be about 1" lower on the highest setting based on the info I gather here. that's about as low I want to go. How about the VBP and Hyperco springs?

* I'm most concerned how the parts work together as a kit. Any specifc combo that works well?

* Spring rates are available, but I couldn't find any specs on the shocks. Anybody got some info there?

* Hyperco and T1 have a higher rear spring rate compared to the front spring. The VBP are the other way around, any input on the reason for that?

Many questions, I hope to get some feedback from useres who have pratical experience from the parts above. Any input appreciated, good or bad. Shoud I aim for somethign else or are the kits above the cure for the chassis in the C5. As of now I'm not interested in going to a full race setup, e.g move suspension mounting points and such, tailor made spring rates and so on.

joemoia

You'll probably get a lot more responses if you post this in the autocross/roadracing section of the forum. There have been many threads discussing suspension set-ups

http://forums.corvetteforum.com/auto...roadracing-23/

C5_Z06

Ok, thanks. Made a thread there as well. Maybe that was my first mistake as a beginer here, that is making two threads.

Bill Curlee

Call Gene Culley. (www.gmpartshouse.com ) Get his C6 ZO6 sway bars for the C5 (direct OEM bolt in pieces) and get a set of C6 ZO6 shocks. They are also 100%OEM bolt in. The shocks are $250 USD new.

Those C6 ZO6 shocks made my 02 ZO6 a LOT more predictable and smooth on rough sweeping turns. They eliminated that side step feeling on washboard turns.

Order an ABS of Steel or ABS of aluminum tunnel plate and install it in place of the stamped steel thin flimsy plate thats in there now.

I have purchased but have yet to install poly urethane bushings. Those baby's with a good performance 4 wheel alignment will surely firm it up!


Those pieces should make a big difference in the way your car feels and handles. Just the shocks and ABS of aluminum made mine a different car.

BC

C5_Z06

Thanks for the input Bill. It doesn't feel as it's the chassis it self that is weak or flexing. I'm pretty sure it's the setting of the shocks/springs. I've read many posts about C6-Z06 parts being very competive priced compared to aftermarket stuff, but in my case I simply want to take one step further, hence the T1 stuff.

Greg_E

If your on a buget, Addco make some nonadjustable sway bars that are very reasonably priced, and fall between the Z06 and T1 bars. They make a 35mm and 32mm hollow front bar. and the rear bar is 25.4mm. If I recall correctly, most of the road racers prefer the 32mm front bar. Addco also offers a solid bar.

Edit: Apparrently, I recall incorrectly. Here is a quote from Raftracer
"If you are autocrossing the 32mm will be a choice piece. If you run on roadcourses the 35mm bar will be best. I have used Addco bars and you will be happy with the performance to value ratio..."


As mentioned you can find more info in the road racing section.

Check with this sponsor. They don't advertise brands, but I'm pretty sure they sell the Addco bars, and can reccommend all the parts that will work together.
http://www.vbandp.com/

Here's some info I collected. As far as I know it's accurate.

Swaybars:
C5 Base Suspension: 23 mm-front / 19.1 mm-rear / 3.81mm/2.0mm thickness
C5 Z51 (97-99): 25.4 mm-front / 21.7 mm-rear
C5 Z51 (00-04): 28.6 mm-front / 23.6 mm-rear / 4.15mm/3mm thickness
C5 Z06: 30.0 mm-front / 23.6 mm-rear / 4.5mm/3.5mm thickness
C6 Base: ?? mm-front / 22.0 mm (7/8")-rear
C6 Z51: 31 mm-front / 25.4 mm (1")-rear
C6 Z06: 31 mm-front / 28.8 mm-rear
C5 Hotchkis: 31.75 mm-front / 25.4 mm-rear / 4mm/4mm thickness
C5/C6 Addco: 32 mm-front / 25.4 mm-rear
C5/C6 Addco: 35 mm-front / 25.4 mm-rear
C5 Pfadt (Adjustables): 32 mm-front / 26 mm-rear
C5 Pfadt (Adjustables): 35 mm-front / 28.5 mm-rear (Pfatty)
C5 T1 (GM Racing): 38.4 mm-front / 27.5 mm-rear / 6.35/6.35 thickness
C6 T1 (GM Racing): 38.4 mm-front / 27.5 mm-rear / 6mm/?? thick