Z06Fix

hey guys I am looking to start upgrading the 03 Z06. I use the car as a DD and run a few autox's with it. I am planning on running 1 or 2 HPDE's next year as well. Anyone have any advise on shock upgrade? I have been seeing that alot of people are very happy with the 04 Z06 shocks. I am coming from running an 03 cobra for OT/autox so this is kind of different waters for me. I was very happy with my Bilstein's on the cobra.

Car is a stock 03 Z06 lowered 15mm on the stock bolts. (not quite all the way down)

Thanks guys!!

JiminVirginia

All I can say, from running my car and reading encouraging posts about the Bilsteins, is you can't go wrong with either of these choices.

John Shiels

Bilstein rebuildable and you can revalve

0Randy@DRM

Bilsteins!!! Back in the day the 04 shocks were pretty cheap. Now the Bilsteins are cheaper and better, why not.

Randy

MungoZ06

MANY threads on this ... '04's, '06 ff Z shocks, Bilsteins ... and no definitive answer ... my take after reading all is that a car lowered more than stock bolts allow may be best on Bilsteins or '06Z or newer shocks, as they may be a bit shorter.
That said, on my street/autox/track time car lowered on stock bolts, I ended up putting '04 Z shocks on my '03 Z, as I felt they were most compatible with the Z06 spring rates and optimized for the Z. I'm happpy YMMV

Z06Fix

Thanks for the input guys. I will do some looking around and see what all I can find.

jbauch357

You can find the full set of Bilstein Sport's for right at $300, it'll be hard to find the same price for '04Z shocks.

FWIW I went with the Bilstein Sports and couldn't be happier, the biggest difference I noticed was stability at speeds ot 100+

briann510

My 03 z06 is lowered 3/4 front and back and while my stock 03 shocks very rarely bottomed out (not nearly as much as a lot of people say they do) they were night and day difference better than the Bilsteins in handling and even straight line tracking.

On the freeway the car bounces more to the point its more annoying than a stiffer riding stock shock and it also lane wanders on slight curves, but I really prefer the more solid feel of the stock shocks better even though the ride is harsher.

For the past week I've been hitting the back road twisties and some fast straight line runs and I am no where near the same handling or speeds through turns. The car is loose and rolls a lot more through the turns. I guess I expected a much better comparison between the 2 shocks but in my opinion Bilsteins suck in comparision vs 03 C5 Z06 shocks.

I will be removing the Bilsteins in short order and go back to really enjoying back road twisties. I wouldnt recommend swapping Bilsteins for Z06 shocks at all.

Jason

FWIW, NASA TT rules charge points for Bilsteins, but not for 04Z shocks. If you're looking down the road.

CHJ In Virginia

I used the Bilstein sport shocks on my 03Z06. Car is lowered to the max on stock bolts and has a track alignment. I like the Bilsteins very much - car is rock solid at speed and through the turns. I would recommend them especially if they are cheaper than the 04 Z06 shocks.

NavyVet

Strongly recommend the Bilstein Sports. Briann510 - if yours are Bilstein sports, I'll take them off your ahnds so I can get a spare set rebuilt.

Bilstein Sports are approximately 1/2" shorter (piston centered) than the stock shocks, so, IMHO, preferable on your lowered car. We use them on our '99 FRC and they are great, but it is mostly a track car. We had an '04 Z06 before the '07 and I think the Bilsteins react better and more consistent under severe cornering than the factory '04 shocks, but that's just one opinion. As noted, the Bilsteins can be rebuilt and anyone who has tried this with the (Tom) Moracca valving will vote for that setup. Good luck.

Z06Fix

This seems very odd. You think maybe you ended up getting the HD version Vs the sport? I know the stock 03 shocks should be better than the Bilstein HD's. Just a thought. I hate to hear you were dissapointed, everyone seems to be so happy with them on both track and street.

BADMFR

I put 06 C6Z shocks on my C5Z and love them. Much cheaper than the bilstein's too.

briann510

Yea part numbers were first thing I re-checked. I guess I have been so used to driving with stiffer shocks, maybe my driving style needs to adjust some. The Z06 shocks though are a lot stiffer compression and rebound and I could control the car easier.

The problem now is through turns the inside rear tire is lifting and losing traction where as before it was solid and planted.

B-ras

Did you change anything else when you swapped the shocks? Have you checked over the suspension to make sure there are no other issues? AFAIK, no shock would make a rear wheel lift (and I assume you mean "inside") under cornering on smooth road. That's more a matter of the other components and geometry.

I'm putting Sports on my FRC this weekend, and have only heard good things about them from those I trust.

0Randy@DRM

The Moracca valving was setup for the C4. I don't think you will be happy unless you have a C4.

Randy

0Randy@DRM

Brian,
This is very weird and very strange for the horrible change in handling. I think we sold you the shocks too. All you changed was the shocks? When the rear tire lifts, does it do it on both sides? or just one? Double check the swaybar too.

I will viewing this thread again!!!!!!
Randy

briann510

No I didn't buy them from you Randy....Yes only changed the shocks. I test my suspension changes on the same road each time so not to have any different road conditions before and after. I hit 16 miles of twisties very very hard and fast almost every afternoon. Before shock change the car was flat and planted like a train on tracks. I always have AH/TC turned off when I run so I know exactly what the car is doing and not letting the computer take over when I go through and come out of a corner faster than the computer says I can.

Never on this road has the rear end ever started to wander coming round a turn or curve or the front react with understeer. I knew before hand the Bilsteins were not going to be as stiff a shock as stock Z06 ones and it was evident right awaywhen I bounced my weight on the fender after swapping them the Bilsteins weren't anywhere near as stiff as the stockers..

Now when I hit same curves and turns the car rolls noticeably more as each shock compresses more easily and rebounds easier and makes the car less stable pitching through the turns. Understandably on a curve or tight turn the car rolls a little more with softer shocks to one side thus lifting inner tires and weight off the ground more. I actually swung the rearend out a few times at xxx speed around a few turns which has never happened before but still maintaining control through it.

I guess after driving 35+ years SCCA, GT-1,2 AND 3 I'm just not used to a softer suspension setup and it will take some getting used to not being able to hammer as hard through the twisties as I'm used to.. I will eventually get coilovers or 12 way adjustables and the Bilsteins were just a shock in between the changeover.

VetteDrmr

Brian,

I think you've got a shock failure of some kind. I've compared Bilstein Sports vs. stock C5 shocks, Z51 shocks, and my current '04 Z06 shocks. The Sports and the Z06 shocks are very, very similar in stiffness, with the Sports maybe a bit stiffer, but definitely, absolutely, certainly, NOT softer.

HTH, and have a good one,
Mike

briann510

4 shock failures? All 4 are the same stiffness. I compared the stiffness of them to my Z shocks off the car and the Bilstein sports were not as stiff. I went yesterday to a parts warehouse and tried compressing same Bilstein sports and they were the same stiffness as what went on my car.

I dont believe Bilsteins are advertised as being as stiff or stiffer than stock Z06 shocks.

Well.....Ill move on now and pass it on to the Mythbusters....