2001 Red Coupe Bandit

I installed Bilsteins with my 2002 Z06 Sways 4 months ago and lowered as much as the stock bolts allow. Love the Bilsteins, but the rears are making my ride very rough! I put the fronts on 1st and then drove the car around. Then i installed the rears so I know how the car rides with each senario.

The fronts are great, but the rears are really getting to me on rough roads, they make my rear and Head go BAM everytime I hit a bump or a road Line. It is making my car feel a bit too harsh!

I am going to put the stock rears back on next week and leave the Front Bilsteins on and see how that feels. I was told a by my buddy (King Tut) that when he put his stock rears on and left the front Bilsteins, that there was no difference in handling charateristics, the only thing that happened is the Jarring over bumpsand the overall ride smoothed out.

Anyone do this? Or anyone feel the Bilsteins are a bit rough in the rear? That is where i feel it, the rear of the car. On smooth roads the Bilsteins are great, but I am getting tired of the harsh go cart like ride. I hope a mixed match combo on the shocks will solve this.

The Bandit................





[Modified by 2001 Red Coupe Bandit, 11:38 PM 8/31/2002]

MelloYellow

Not sure how low you are in the back. Are you bottoming out the shock and bouncing off the leafs? You could cut the bump stops in half. I did that to all 4 before install. If you are unhappy with the shock rate, nothing u can do about that.

What are your fender heights F/R?

2001 Red Coupe Bandit

I am not that low. I actually raised the back (from the lowest stock bolt point) slightly to keep the raked look.

The rear I don't think i have to worry about bottoming out, just the front.


[Modified by 2001 Red Coupe Bandit, 7:07 PM 9/1/2002]

EMDExpress

Are you running the runflats? If so, thats your problem. :smash: :yesnod: :lol: :seeya

Jim 47

Bandit:

It sounds to me that you are definately bottoming out on the Bilsitein shocks. You didn't say which Bilstein Shocks you installed. Are they the Sports or the Heavy Duties? The Sports should work OK on a lowered C5, if installed correctly, while the HD's won't.

Check to see if you have allowed the maximum in compression travel on the Bilsteins. It is possible to install them incorrectly and actually reduce the compression travel, which causes the problem that you are describing. :cool:

chuckster

I never understood how you guys bottom out. :confused:

I still have the stock Z51 Shocks, I lowered 1.5"by cutting front and rear bushings. I have NEVER Bottomed out. Even flying over railroad tracks.

:confused:

Z06 Mike

Lose the RunCraps!!

2001 Red Coupe Bandit

Thanks Guys, but let me better explain myself. I am Not bottoming Out my car at all!? At Least that I know of. It is just that the car feels really harsh (in the rear) when you get on a rough road.

I do Have RunFlats though,,,,,,,,,,,,,,,,hum?? maybe that is part of the problem? I installed them myself, but I am sure I installed them correctly.

I wonder how much the runflats make a difference on the feel of the shocks or the ride quality. The stock shocks felt pretty good in terms of a soft, not jarring ride. My car is lowered, but again, just an inch in the back and a little less than that in the front.


To test it out, I might just put the stock rears back on like I was saying and see what that does. I mean if bottoming out was a problem (which I don't think is the case) then the stock rear shocks would bottom out worse than my bilsteins since they are not as firm as the Bilsteins. Again, I suspect ride will be close to the same as before without the Jarring and harshness I feel over every bump.

Thanks

The Bandit...........


[Modified by 2001 Red Coupe Bandit, 7:16 PM 9/1/2002]

MelloYellow

Bottoming out is a bbbbBOUNCE type feel.
Hard thudding... ditch the runflats and/or lower your tire pressure a bit.

John Shiels

When I put the sports on my car I lowered it the max with the stock bolts and then raised it. It didn't handle worth a dam and did feel like it was bottming out as you say. The back looked lower than the front and did measure that way too going to the top of the wheel well. If you are looking to handle the botto to me is not the answer. :seeya

2001 Red Coupe Bandit

Yeah, the feel is a Hard Thud, not a bounce. On a well paved road they float and feel really smooth.

I did just air up my tires and was running 30 PSI col and when they are heated 32 PSI. i might lower a bit.

It also bothers me when I hit a long patch of rough road, the car almost feels like it is out of control, not like I am going to loose it, but it vibrates and shakes violently and feels like I am in a go cart. i have had them in for 4 months, but my car is a weekend car and the more I drive it lately the more I notice the thuds.

Bandit...........................

The Bandit

Jim 47

Bandit:

The "Hard Thud" you feel is the shock absorber being fully compressed. The shock absorber "is " the thing the limits the upward travel of the suspension. If the "compression" distance has been limited by lowering the car (which evectively is raising the wheel position relative to the car), or the shock absorber has been installed in a way that reduces the compression travel that the rear suspension needs to do its job, then you WILL FEEL A HARD THUD.

If the THUD goes away after you have installed the stoch shocks, and nothing else was changed, then you have provided the suspension more upward (or compression) movement with the stock shocks and nothing more. The difference in the "stiffness"of the shock is NOT what is causing the THUD. It is being caused by the lack of adequate upward movement (or compression) distance that the shockabsorbers will allow before becoming fully compressed.

It would be an easy thing to compair a stock shock with a Bilstein and measure the fully compressed dimention. If the stock shock is shorter between the bottom bolt holes to the top of the bottom rubber bushing on the top of the shock, then the stock shock has more compression room.

If it's a HARD THUD you are feeling, it NOT being caused by your tires or the compression or rebound stiffness or your shocks. Sure, these elements will affect handeling and ride but they won't cause Hard Thuds. :cool:

magnetic1

In regards to the rough roads and the car feeling like it is going all over the place.... you never did mention if you got your car aligned after you installed the shocks... This could be a cause for this if the settings changed during your numerous lowering/raising, and changing shocks in/out.

I had Bilsteins installed, front and rear with no issues after I got my alignment done. True, the car rode rougher.. but it never seemed out of control. I also do not have run-flats.

2001 Red Coupe Bandit

Anyone else have this Thud over hard Bumps?

I don't see how I could have installed the rears shocks wrong? They are pretty easy.

How can I tell if they are being compressed or if I am having a problem?

Thanks

Jim 47

Bandit:

I have lowered the rear and the front of my FRC as low as possible without cutting the bushings and using the stock bolts in the rear. I also have the Blistein Sport shocks installed and I have NO harsh ride or hard thuds over large or small bumps. Maybe you have the Bilstein Heavy Duty schocks which do not allow as much compression travel as the Sports.

Also, I remember when I ordered my Sport shocks, there was a hold on shipping them because they were getting complaints from Corvette owners who were experiencing this "bottoming/ Hard Thud" problem. It was determined that the problem was that the shocks were not installed correctly. Once this was determined, they started shipping the shocks again.

Also, I remember when I installed the Bilstein Sports, there were at least two ways, probably more, that the upper bushings/washers/spacers could be arrainged on the shaft, several of which reduces the compression travel of the shock. It appears from your statements that you either have the HD's on the car or they are not installed correctly. :cool:

Fahtrim

I did the same thing (kinda) with my Mustang. Put the lowering springs on the front only.

corvette_karl

Dude, Getting rid of the run-flats will be the best "mod" you ever make.

I have the Bilstein sports and the Hotchkis sway bars, with the base springs. My car is also lowered to the extent that yours is.

I actually feel that the rear is a little soft and want to increase the spring rate in the not too distant future.

I did think it was "rough" and "jarring" when I had the run flats, though. They are just too hard.

Karl