I searched for threads on C6 shocks and there is no defintitive answer on which are better for autocross/street use on a stock C6 Z51 suspension.

Choice 1: Bilstein Sports
Choice 2: C6 Z06 Shocks
Choice 3: C5 Z06 Shocks

Real world experiences on these would be helpful. There is a significant price difference between the C5 ($80) and C6 ($50) Z06 shocks, leading me to believe that the C5 Z06 shocks are better.

 

One of the parts vendors on this forum feels that the price difference between the 04 C5 Z06 and C6 Z06 shocks is only due to how much the supplier wants to charge and that he's seen certain OEM parts go up or down significantly over time. The C6 Z06 shocks are a big hit in the C5 sections. Overall they seem to be impressed, including a few C5 Z06 owners. Based on the posts I've read I'd guess that they are somewhat similar.

I put the C6 Z06 shocks on my C6 Z51 and see some improvement on the street. I did not autocross. I don't know how they would compare to Bilstein Sports, however.

I guess everyone has different opinions. Over the past few years I've read some C5ers say they prefer the Bilstein Sports and some prefer the 04 Z06 shocks for autocross. I havn't seen any posts from C6 owners talking about the performance of the Bilsteins or C6 Z06 shocks for autocross.

 

They are different part nos. between C5 and C6, but of course that is not a tell tale. I know a few of the C5 Z06 autocrossers who compete at SCCA nationals and they say the Z06 shocks don't need to be changed. Even Penske double adjustables are but a fraction better than the factory C5 Z06 shocks...and only in certain track conditions. Seems like those shocks are optimal for that suspension.

Thanks for sharing.

 

Someone questioned the wisdom of using any C5 shocks on the C6 because the latter has greater suspension travel, perhaps over-traveling a C5 shock. Opinions?

Does Bilstein make a C6 shock now? Last time I looked on the website I couldn't find one. I had Bilstein Sports on my Z51 C5 and they were a little stiff for street work (but i used it as a daily driver anyway) but perfect for autocross or road courses. Still perfect when I traded the car at 68,000 miles.

 

I have them on my C6 Z51, made a world of differance. I think they are on several websites now. Corvette Garage for sure.

 

The Bilstein Sports are a superior shock and work very well on the C6. I don't feel the ride is as harsh as the 51 shocks, and in multiple twistys the car feel much more stable. The metering is the shocks are different and having good shocks is huge. My C6 has been lower a bit. Very happy with bilstein shock.

RansRods

 

I have lived with the Bilstein sports for about 200 miles now and have the following observations. I do think the ride is a bit harsher on rough roads. The performance increase is as everyone says it is. The very controled rebounds are a welcome in that the bouce that is annoying on the Z51 shocks is completely gone. The handling is improved with less lean. The car is more stable at high speeds. I have only been to 115 but its enough to say it is more planted than the stock set-up. My car is lowered fully on the stock bolts and I think that may contribute to the harshness that I feel where others dont think it is objectionable. I sometimes find myself saying how smooth my new car was before I touched the motor and suspension but when I beat on the car to extract performance, I get a return of massive supercar level running that I wouldn't dream of ever giving up. For a lowered car, I would think the sports may be too much for most people. The HD's may be the better choice. As for Z06 c5/c6 or bilstein, I vote these everytime with attention paid to other varibles such as ride height and road conditions. E-shocks charged me 299 shipped and I'm not giving them up.

I hope this helps.

 

My car is lowered and I love them(Bilsteins). Rough roads are rougher but the ride has improved dramaticaly! I've also noticed that I don't scrape as much!!! Best mod yet!!!

BTY...I spoke to someone at bilstein and they don't intend on making a C6 specific shock as the previous model works just fine.

 

Z06 swaybars, and Z06 shocks on mine, ride feels the same but with more control, faster stability of the car, and easier to be stupid and power slide and whatnot. Only cost me $216 shipped to my door, and $30 for the wrench and socket big enough to change the shock out.

With aftermarket tires, non-runflat, and stiffer swaybars, and upgraded shocks, this car is sick on the handling. It down right scars the crap out of me on how fast and hard I can take a corner or do a lane change. With smoother ride, less noise, and supercar handling, I have seen over 1.08G on my G meter in tight corners, and 1.10 and higher on large sweepers. This is the level of handling that I have been dreeming of, and can't wait until our next autocross event, considering I just missed the one last Friday. I am sure with the new setup that I will drop about 8 to 10 seconds a lap.

 

Don't know what year you have, but in case:

1997-2005 Chevrolet Corvette 2004-05 Cadillac SLR Lower Rear Shock Attaching Bolt May Break After Torqued - kw suspension stud rear #PIC3359 - (Jan 28, 2005)

1997 - 2005 Chevrolet Corvette 2004 - 2005 Cadillac XLR Lower Rear Shock Attaching Bolt May Break After Torqued

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in the PI.

Condition/Concern:
The rear shock lower attaching bolt may break when tighten to the proper torque of 162 ft lbs (220 40 N/m) after being removed for service.

Recommendation/Instructions:
Anytime the rear lower shock bolt is removed for service. Replace the shock attaching bolt with part number: 14048990 and Nut with part number: 11516383. The bolts are torqued to yield and are one time use only. Torque the bolt to the new torque of 107 ft lbs (145 10 N/m) as opposed to the current released torque of 162 ft lbs (220 40 N/m) in SI2000.

Note: When tighten the new bolt to factory spec, The nut must be held secure and the torque should be applied to the bolt head only.

Please follow this diagnosis process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.

Models:
(97-05 Chevrolet Corvette) and (04-05 Cadillac XLR)

 

"Swell"

Harry Callahan

 

I have an 05 - thanks for the tip.

162 ft-lbs????? What are they thinking?

 

FYI, the 04 Z06 shocks and the C6 Z51 shock are basically the same part. There are minor differences to accomdate longer C6 travel, but damping rates and valving are the same. So you are just wasting money that route, IMO.

Not 100% relevant here, but switching to Bilsteins from stockers on my C5 Z51 was like night and day.

The C6 Z51 shocks on my new baby are a major improvement, but there is some slop remaining, especially on rebound. I have driven cars on Sachs, Boge (BMW) and Bilstein (Mercedes OEM and my Z51 Coupe) and nobody gets rebound control like Bilstein does.

In fact, if I had the choice between C6 Z06 shocks and Bilstein Sports, I'd still get the Bilsteins. You can always send them in and have valving firmed up if you like.

 

I am leaning towards the Bilstein Sports. They are only fractionally more $$$ than the Z06 shocks. Chevy used to put Bilsteins in the Corvettes, my C4 had factory Bilsteins. But they were not aggressively valved of course.

 

Bilsteins are BY FAR the best mod I've done to date. I'll know for sure when I hit the track next month.

 

I recently added 2006 Z06 shocks to my 2005 Z51 MN6. Rebound is considerably improved all around. The rear end feels more "planted" and the front end does not seem to bottom as easily. Did a 4 wheel alignment at the same time. Stability at highway speeds is improved, steering feels more responsive as well, with better on center feel and no wandering. Stock runflats are set at 32 PSI. A highly recommended mod. IMO, can't see the need for any suspension mods beyond the Z06 shocks for street use. Ride is quite acceptable, without the previous "float" on undulating roads or at cruising speed. Would do an alignment at the same time they are installed. Camber and toe were OK on mine, but caster was way off pre-alignment.


Can't comment on the Bilsteins as I have no experience with them. Went with the C6 Z06 shocks as they are specifically designed for that chassis and I didn't want to alter the balance. The rest is stock Z51. Don't change to the C6 Z06 rear bar, as it will make the car oversteer even more. If you do elect to go with the Z06 rear bar, I would also add the Z06 front spring, so the front/rear balance is kept more or less the same. Rember, stiffening up the rear alone will only increase oversteer. Try the shock mod first before doing anything else and evaluate it. I am quite pleased and believe it was money well spent.

 

I was going to change my shocks until I found out that they are made by Sach's, so I may get the Z06 shocks since they are made by Sach's also.

 

It feels like my c6z51 is way softer than my c5z. The springs must be diffferent as well.

 

8 - 10 seconds a lap? You must be running the Nurburgring.

 

Las Vegas Speedway Baby!

Just exagerating, maybe 2 to 3 seconds compared to my stock setup! That would be awesome, just saying that this is how much more confident I am with the car due to the better shocks, bigger tires, and stiffers swaybar setup!