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Installed Bilstein Sport Shocks. Driving Impressions.

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Old 06-30-2009, 11:53 AM
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PowerLabs
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Default Installed Bilstein Sport Shocks. Driving Impressions.

After hearing a lot of good things about Bilstein Sport Shock Absorbers I decided to give them a go. My setup is as follows:
2006 C6 Z-51 with a supercharger. The car weights 3180lbs minus fuel currently (weight reduction: Headers, lightweight flywheel, 18" rear wheels, non run flat tires).
Suspension mods: Stock C6 Z-51 springs, C6 Z06 Rear Swaybar agressive alignment (-1 Rear Camber, -1.5 Front Camber).
The car rides on Toyo Proxes R888 Road Racing tires. 265/35R18F, 305/35R18R. Those tires were good for 1.24"G" lateral force at an autocross once warm, so I really can't say there was anything lacking in the suspension in the first place. I originally wanted coilovers, but I was so impressed with the handling after doing the R-Compound tires, alignment, and the C6Z rear swaybar, that I couldn't justify the cost.

I removed the stock Z-51 shock absorbers with 52,000 miles on them. During that time, those shocks saw 2 coast-to-coast cross country trips and some driving in the worse roads this country has to offer (its a toss up between Detroit and Manhattan, IMHO). I've nailed potholes so violent that they bent rims and popped tires, and I've had the car airborne a couple of times.
To my surprize, the stock shocks were still in perfect condition. No leaks, no oil, no odd sounds, perfect return to original position, and a LOT of pressure.

Driving impressions:

After about 150 miles I must say the Bilsteins are really not much different from the stock Z-51 shocks. I've ridden in some very harsh cars (cars with race suspension and coilovers), I've owned some harsh cars (my 2005 Subaru STI was sprung WAY harder than any C6 I've sat in, and the car I had before that was on Coilovers), so I was expecting that the car would ride stiffer.
It really doesn't. If I try to imagine there is something different I can say that maybe its a little bit more solid when it hits bumps, but I would say the difference between the Bilsteins and the stock C6 Z-51 shocks is no greater than the difference between how the shocks feel when they are cold vs when they are warm.
Handling wise I did not notice much difference either. It does not exibit any more (or less for that matter) tendency to bump steer than it did before. On rapid transitions there might be a little bit less body roll, but again its hard to tell. Nothing dramatic.

The ONE advantage was that although going to 18" rears cured my wheelhop (which, at 600RWHP, had become intolerable on 19" Michelin PS2s!), the car still hopped when the road was wet. I purposely tried to make it wheelhop again after the Bilsteins under the same conditions that would do it before, and I found that the new shocks really DO help control wheelhop enormously; I can feel the tires try to hop, but they never manage to really do it; there is just a little shake from the rear when I try a low RPM clutch dump on wet tires (something that before would have the car hopping so bad I'd be forced to lift immediately).

Overall this is not a must if you already have Z-51 shocks and they are in good condition, but it is definitely something I would consider on a car that is having wheelhop issues. I can also attest that they are not too harsh for a daily driver.
Old 06-30-2009, 11:54 AM
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PowerLabs
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Default Installation Tips

For my install I relied mainly on the forum... I lifted the car and supported it on jackstands on all 4 corners:


Removing the rears:


The fronts:


Disassembling the front shocks:


New front in:


This bolt snapped at only around 100ft-lbs. Several other members have had this problem. Ordered a new one from the dealership and substituted with a 5/8 x 11 4.5" long grade 8 bolt:

Last edited by PowerLabs; 06-30-2009 at 12:38 PM.
Old 06-30-2009, 12:00 PM
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If you had gotten Koni FSD's you would have something to write about!
Old 06-30-2009, 12:01 PM
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on a base model the difference is night and day!! best mod so far on my base model was: Z51 sway bars, bilstein sport shocks!
Old 06-30-2009, 01:08 PM
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Nice write-up and pics. Thanks.
Old 06-30-2009, 01:16 PM
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Originally Posted by miami08VETTE
If you had gotten Koni FSD's you would have something to write about!
I installed FSD's this past winter. Night and day difference. The car now stays planted in corners with a rough surface, no more rear end side step..The best way to describe the difference is that the harshness is taken out of the ride with the Z51 shocks. Man those things have a lot of gas pressure..The car dropped between 1/2" and 3/4" with just the shock change..
Old 06-30-2009, 01:36 PM
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About how long did it take you to swap them?
Old 06-30-2009, 02:03 PM
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I ditched my z-51s at 2,000 miles on the odo. for a set of bilstien's.... no more wheel hop at the track, eliminated that "floating" feeling at 140+++ & that nasty steer bump
Old 06-30-2009, 02:31 PM
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Originally Posted by FloydSummerOf68
About how long did it take you to swap them?
I took me about 3 hrs total..Wheels up to wheels down. The first 45 minutes was on the first front shock..It took a bit to figure out how I was going to use the ratchet strap to compress the OEM shock..Once that was figured out, about 20 mins per shock.
Old 06-30-2009, 02:55 PM
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Originally Posted by PowerLabs
After hearing a lot of good things about Bilstein Sport Shock Absorbers I decided to give them a go. My setup is as follows:
2006 C6 Z-51 with a supercharger. The car weights 3180lbs minus fuel currently (weight reduction: Headers, lightweight flywheel, 18" rear wheels, non run flat tires).
Suspension mods: Stock C6 Z-51 springs, C6 Z06 Rear Swaybar agressive alignment (-1 Rear Camber, -1.5 Front Camber).
The car rides on Toyo Proxes R888 Road Racing tires. 265/35R18F, 305/35R18R. Those tires were good for 1.24"G" lateral force at an autocross once warm, so I really can't say there was anything lacking in the suspension in the first place. I originally wanted coilovers, but I was so impressed with the handling after doing the R-Compound tires, alignment, and the C6Z rear swaybar, that I couldn't justify the cost.

I removed the stock Z-51 shock absorbers with 52,000 miles on them. During that time, those shocks saw 2 coast-to-coast cross country trips and some driving in the worse roads this country has to offer (its a toss up between Detroit and Manhattan, IMHO). I've nailed potholes so violent that they bent rims and popped tires, and I've had the car airborne a couple of times.
To my surprize, the stock shocks were still in perfect condition. No leaks, no oil, no odd sounds, perfect return to original position, and a LOT of pressure.

Driving impressions:

After about 150 miles I must say the Bilsteins are really not much different from the stock Z-51 shocks. I've ridden in some very harsh cars (cars with race suspension and coilovers), I've owned some harsh cars (my 2005 Subaru STI was sprung WAY harder than any C6 I've sat in, and the car I had before that was on Coilovers), so I was expecting that the car would ride stiffer.
It really doesn't. If I try to imagine there is something different I can say that maybe its a little bit more solid when it hits bumps, but I would say the difference between the Bilsteins and the stock C6 Z-51 shocks is no greater than the difference between how the shocks feel when they are cold vs when they are warm.
Handling wise I did not notice much difference either. It does not exibit any more (or less for that matter) tendency to bump steer than it did before. On rapid transitions there might be a little bit less body roll, but again its hard to tell. Nothing dramatic.

The ONE advantage was that although going to 18" rears cured my wheelhop (which, at 600RWHP, had become intolerable on 19" Michelin PS2s!), the car still hopped when the road was wet. I purposely tried to make it wheelhop again after the Bilsteins under the same conditions that would do it before, and I found that the new shocks really DO help control wheelhop enormously; I can feel the tires try to hop, but they never manage to really do it; there is just a little shake from the rear when I try a low RPM clutch dump on wet tires (something that before would have the car hopping so bad I'd be forced to lift immediately).

Overall this is not a must if you already have Z-51 shocks and they are in good condition, but it is definitely something I would consider on a car that is having wheelhop issues. I can also attest that they are not too harsh for a daily driver.
Good info, you saved me some time and money, thanks!
Old 06-30-2009, 03:03 PM
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Originally Posted by miami08VETTE
If you had gotten Koni FSD's you would have something to write about!
Yes I would ... This:

Originally Posted by nwc6
I installed FSD's this past winter.
The car dropped between 1/2" and 3/4" with just the shock change..
See, for me that is inacceptable; my car is already too low for NJ roads and scrapes daily... That's wha kept me from the FSDs...
Old 06-30-2009, 03:07 PM
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Originally Posted by PowerLabs
After hearing a lot of good things about Bilstein Sport Shock Absorbers I decided to give them a go. My setup is as follows:
2006 C6 Z-51 with a supercharger. The car weights 3180lbs minus fuel currently (weight reduction: Headers, lightweight flywheel, 18" rear wheels, non run flat tires).
Suspension mods: Stock C6 Z-51 springs, C6 Z06 Rear Swaybar agressive alignment (-1 Rear Camber, -1.5 Front Camber).
The car rides on Toyo Proxes R888 Road Racing tires. 265/35R18F, 305/35R18R. Those tires were good for 1.24"G" lateral force at an autocross once warm, so I really can't say there was anything lacking in the suspension in the first place. I originally wanted coilovers, but I was so impressed with the handling after doing the R-Compound tires, alignment, and the C6Z rear swaybar, that I couldn't justify the cost.

I removed the stock Z-51 shock absorbers with 52,000 miles on them. During that time, those shocks saw 2 coast-to-coast cross country trips and some driving in the worse roads this country has to offer (its a toss up between Detroit and Manhattan, IMHO). I've nailed potholes so violent that they bent rims and popped tires, and I've had the car airborne a couple of times.
To my surprize, the stock shocks were still in perfect condition. No leaks, no oil, no odd sounds, perfect return to original position, and a LOT of pressure.

Driving impressions:

After about 150 miles I must say the Bilsteins are really not much different from the stock Z-51 shocks. I've ridden in some very harsh cars (cars with race suspension and coilovers), I've owned some harsh cars (my 2005 Subaru STI was sprung WAY harder than any C6 I've sat in, and the car I had before that was on Coilovers), so I was expecting that the car would ride stiffer.
It really doesn't. If I try to imagine there is something different I can say that maybe its a little bit more solid when it hits bumps, but I would say the difference between the Bilsteins and the stock C6 Z-51 shocks is no greater than the difference between how the shocks feel when they are cold vs when they are warm.
Handling wise I did not notice much difference either. It does not exibit any more (or less for that matter) tendency to bump steer than it did before. On rapid transitions there might be a little bit less body roll, but again its hard to tell. Nothing dramatic.

The ONE advantage was that although going to 18" rears cured my wheelhop (which, at 600RWHP, had become intolerable on 19" Michelin PS2s!), the car still hopped when the road was wet. I purposely tried to make it wheelhop again after the Bilsteins under the same conditions that would do it before, and I found that the new shocks really DO help control wheelhop enormously; I can feel the tires try to hop, but they never manage to really do it; there is just a little shake from the rear when I try a low RPM clutch dump on wet tires (something that before would have the car hopping so bad I'd be forced to lift immediately).

Overall this is not a must if you already have Z-51 shocks and they are in good condition, but it is definitely something I would consider on a car that is having wheelhop issues. I can also attest that they are not too harsh for a daily driver.
Just getting ready to get a set of these, I'm doing a spring change at the same time. Base to z-51! I have 7k on a set of z-51 shocks.
Old 06-30-2009, 04:52 PM
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Originally Posted by CMY SIX
on a base model the difference is night and day!! best mod so far on my base model was: Z51 sway bars, bilstein sport shocks!
I installed the sports on my base car with stock sway bars (Z51 sways on order). After putting a few hundred miles on them I can honestly say it has transformed the car. Before, it would "float", though it had an excellent ride. Now, it's BMW "Sport Package" in feel and ride. I pushed the car so hard in one corner the active handling was intervening as the car was overpowering the tires and I felt confident, were before the car was way too loose and I was having trouble finding the edge. The stock base shocks are incredibly puny and are now resting in some landfill.

The sports are stiffer than the stock base shocks, but you won't really notice it after a few miles. The ride remains excellent. But, if you are really worried and don't ever plan on pushing the car go the with HD version. Same shock just valved a little softer. Also, don't worry about what bilstein recommends on which shock to use, that is just general guidance. The F55 suspension uses the same spring rate but a shock that can switch between dampening settings at any moment. And, there are plenty of high dollar aftermarket shocks that are adjustable without having to match spring rates.

Install tip: You can use plastic tie wraps to hold the shock. Tie one in a small loop around the top, then use one or two more to connect to the bottom (suspension under load). At this point I just grabbed the front shock and compressed it about an inch by hand while taking out the slack in the tie wrap. Without uncompressing the suspension the shock fell out. In the rear you'll probably have to unload the suspension to get the shock out after you have tied it up.

Installing the new shocks is even easier as you can compress by hand on the work bench then tie the shock up tight. Use wire cutters to cut the plastic tie wraps once the shock is in place.
Old 07-01-2009, 04:10 AM
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Originally Posted by PowerLabs
Yes I would ... This:



See, for me that is inacceptable; my car is already too low for NJ roads and scrapes daily... That's wha kept me from the FSDs...
....Did I just see you on the science channel????
Old 07-01-2009, 05:55 AM
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Originally Posted by nwc6
I took me about 3 hrs total..Wheels up to wheels down. The first 45 minutes was on the first front shock..It took a bit to figure out how I was going to use the ratchet strap to compress the OEM shock..Once that was figured out, about 20 mins per shock.
I found it easier to remove the two upper control arm bolts to install the fronts.

Last edited by timd38; 07-01-2009 at 07:46 PM.
Old 07-01-2009, 06:19 AM
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I did a Z51 vs Bilstein Sport shock thread on the swap in 2005 and thought it was a big difference. The wheel hop improvement alone was worth the difference although it took some time for this to manifest. At first there wasnt an improvement. The 18" wheels fixed that completely. The thing I recall as the biggest improvement was that the control improved at higher speeds and over rough roads. The Z51's seem to compress and get harder on subsequent bumps while the Bilsteins reset and handled each bump as an independent event vs one compression of the stockers until the road cleared. In other words, the sports reset fast enough to handle lots of little bumps while the stockers compressed until the road was smooth then reset.

300 bucks is well worth it. 14k miles and 3.5 years later it still rides controlled and refined.

Warning: Aintqik's car which was slammed really low caused the sports to leak. 2 were dead/oil leaked the year he put them on.

Last edited by SpinMonster; 07-01-2009 at 06:22 AM.
Old 07-01-2009, 06:37 AM
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Just a light-hearted moment here, but, from this thread:


Originally Posted by PowerLabs
The car rides on Toyo Proxes R888 Road Racing tires. 265/35R18F, 305/35R18R. Those tires were good for 1.24"G" lateral force at an autocross once warm, so I really can't say there was anything lacking in the suspension in the first place. I originally wanted coilovers, but I was so impressed with the handling after doing the R-Compound tires, alignment, and the C6Z rear swaybar, that I couldn't justify the cost.
and from my Tractionmonster thread nearly 2 years ago:

Originally Posted by SpinMonster
Although disenting opinions exist about the validity or accuracy of the car's onboard G-meter, it can be used to note a CHANGE in performance in that if you alwasy saw .98 with noises and discomfort in the confidence of the limits, then you see 1.15 to 1.2g's for short bursts, you have improved. Take it with a grain of salt that it isnt comparable to skid pad tests done by major magazines...


Originally Posted by PowerLabs
I'm not a big fan of generalizations...

ALSO... You keep posting arbitrary numbers you read off from your HUD peak hold display. While those numbers are no doubt very impressive, and I am sure your car handles much better than it did before, I will be the first one to call BS that your car, or any Corvette for that matter, can in fact pull 1.2Gs on the skid pad. For starters there is NOT ONE factory car in the world that can do that. A Formula 1 car will do 1.38 with downforce; anything else on street legal tires will be hovering right around 1G which is what gravitational downforce allows them to do. When I had a G-tech I found that I could generate very high side loads by jerking the wheel; that rapid transient will produce a big peak number, but it is by no means representative of what your car can do in a skidpad under sustained, constant conditions. Same goes for, say, taking a corner on a banked turn; it'll produce a big impressive number, but it is a useless number for comparison with the factory or magazine posted skidpad numbers of 0.96G stock, or .98 for the Z51, or 1.02 for the Z06.

Not saying this to bash you or anything; I'm just clarifying because most people that read a claim that your car can pull "1.2G" will think you have improved the factory grip by 0.6Gs, when in fact you have not. I'd be willing to bet that even though your car handles MUCH better with these new tires, it would still struggle to pull more than 1.05G on a proper, standartized skidpad test.
Come to think of it, that would be a good test for you to try if you ever have the time....
I guess I should have said my car reads 1.2g's lateral force on the HUD and G-tech.

Now Sam, while those numbers are no doubt very impressive, and I am sure your car handles much better than it did before, I will be the first one to call........

They say if you wait long enough.

Just messin with you bro.

Last edited by SpinMonster; 07-01-2009 at 07:03 AM.

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Old 07-01-2009, 07:57 AM
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I was told a c6 T1 car pulled 1.6 g running hoosiers a6. I am planning to install tracmate in my car so I will see what I can pull with a6 and my penske coilovers.

I know for a fact that on the track in right hand turns people are running more that 1.2g with r compound tires because this is when people are starting to see issues with oil pressures.

Amazing what good tires and some suspension changes gives you.
Old 07-01-2009, 08:34 AM
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Originally Posted by Wicked Weasel @ ECS
I was told a c6 T1 car pulled 1.6 g running hoosiers a6. I am planning to install tracmate in my car so I will see what I can pull with a6 and my penske coilovers.

I know for a fact that on the track in right hand turns people are running more that 1.2g with r compound tires because this is when people are starting to see issues with oil pressures.

Amazing what good tires and some suspension changes gives you.
Old 07-01-2009, 09:01 AM
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If trying to control wheel hop only would it be recommended to replace the rear shocks only? factory stock Z51 suspension MN6. I do not track the car and am running PS2 also. Do not really feel like running the 18 on the rear. Or is there a better alternative to control the wheel hop? This would be just for the occasional run down the drag strip. I do have the factory wheels sitting in the garage that I could use the 18" fronts for some DR if I really wanted to. Thanks.


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