I've got KYB AGX shocks and Eibach Pro-Kit springs on my car. I personally feel that the rear of the car is too soft and would like to jack it up a little bit. I've seen the adjustable perches for the rear made my Ground Control and I think I'd like to try running these.

Anybody out there running these and if so what springs do you run? Could I still run my Eibach springs on these if I want to and just bring the car up some until I get money for more springs?

Car isn't autocrossed but I may start sometime soon. It's mostly a weekend warrior so it gets pushed when I drive it.

 

The Ground Control rear kit cannot use the Eibach rear spring. The spring is too long. But, the kit goes include springs for the adjustable height perches as part of the price. A rear set is $199, and you can pick your spring rate. Have you tried adjusting the shocks to firm the rear up? If not, try that first, as we want to stay with a softer spring if possible. I'd run a 125, but we can go higher if you really feel you need it. If you like it better with more shock damping, then going higher probably isn't necessary.

 

Excuse my ignorance, but I was told that these shocks are adjustable only on the slow rebound damping - is that correct?

Also, I have been told that increasing the slow rebound damping on the rear of the car will help transfer the weight faster to the loaded tire and make the car turn in better. It will increase the stiffness of the rear end quite a bit and make the overall ride harsher. If you have too much damping the car will start to lose its progressiveness and you get snap oversteer and at that point you need to back off the damping and start looking into different sway bars.

Do you sell Ground Control stuff Sam or do I have to go direct to them?

There's a guy on this board (don't recall the name) that is running these perches on the rear of his car with Bilstein HD shocks that he autocrosses and he's got 150 #/in springs on the rear - you think 125's are good enough for the rear? The Pro-Kit's I have in the rear are 94-160 #/in I was told.

Sorry to make this so long, but now I've gotten to thinking that maybe I should make the front adjustable ride height too. The fellow's website I'm looking at has Ground Control adjustable perches on the front of his car - 600 #/in springs on Bilstein shocks. Can I put those adjustable sleeves on my KYB's? If so where would I go about getting them and what's the cost?

 

All good questions.....

Whoever told you that about the KYB's is incorrect. They adjust the compression and the rebound (and not low and high speed separately). Generally as you turn shocks up, the end you make stiffer will then react more quickly. If you want the car to turn in better, you'd more want to monkey with front damping. I can't think of a situation that you'd want to run the rears stiffer than the front, I also wouldn't run the AGX's @ full soft in the rear. Shocks are IMHO the most critical component on the 4th gen's suspension. THe AGX's are ok, but not great. What we don't want to do is try and band-aid a shock issue with springs.

I do sell GC stuff. As for spring rate, I was under the impression you had stock springs. Oh well, that might change things a bit. Actually, I wouldn't dare try and give you specs online, for that reason..... I can't know what you have, and what you want to fix.. Best bet is to give a call so you can discuss what you have, and what you want to change about the car.

You can put the GC kit on the car, but not the same ones as the Bilstein shocks use. The kit is $425 (front and rear, including springs).

 

I don't want to talk about your setup much as some people just don't like that.

But I have used KYB AGX's. Bilsteins, and soon Konis. TRUST ME.....You would be much much happier with other shocks.

And like Sam mentioned they don't adjust low speed rebound. Good shocks do however.

No the Ground Control front setup will not work with those shocks. They are just way to big around. And PLEASE DO NOT BUY FROM GROUND CONTROL!

They make great quality parts. But I would like to knock some heads together over there. Save some hassles and just buy from Sam.