hello , I had an auto-x yesterday.

and on hard turns I heard a hard clunk comming from the rear . I thought it might be the bumpstops ..



The car is on GAB 8 Shocks , with ground control coil overs 650f / 500 Rear .

They are set to 3/8 in the front , and 1/8 in the rears .

Running hankook rs-3's 245 f , 255 rear ( yes I know I wish i had a square setup trust me hah )

the car is at 13inches from center of wheel to fender all around .

the car is giving me a bit oversteer , But for the most part its not much , and if i harden the fronts it starts to push .

so My question is if I'm hitting the bumpstops would it be a better solution to harden the setup all around to stop the car from hitting the bump stops . it felt like it dives pretty hard on braking to . I do have a couple videos from the event But most of the issiues the car has in the videos are due to driver error LOL . but I will upload them if it will help also I dont hear the clunk in the videos But I heard it pretty clear when driving it

 

are you sure it isn't the springs getting loose on the collars?

 

honestly I'm not .. and thanks for the reply

here are a couple videos

 

After watching the first video it looks like it only happens in transitions like slaloms and stuff, I'd say that's exactly what's happening.

I would get some Hyperco helper springs (0 rate) to keep them in their perches.

Here are some on my FC:


Helper spring:
http://www.hrpworld.com/store/defaul...er-spring.html
spring guide:
http://www.hrpworld.com/store/defaul...ing-guide.html

 

Ohhh nicee that looks great! Thanks

 

I have had a similar situation on the rear using Koni yellow double adjustable coilovers, Hypercoils with the thin spring spacers. When hitting a substantial pot hole or other bump, there would be a loud bang from the rear, like metal on metal.What I found on taking off the suspension was that the back right shock had lost the compression valving and the spring was bottoming out. Note that you lose the stock rubber bottoming bumper when you convert to coilover on the back. Koni makes a "donut" rubber ring that goes over the shock rod to act as a bottoming bumper. You may want to add that to your setup so that there is some rubber to cushion the shock if it completely compresses.

 

What is your ride height measured from the ground to the middle of the fender lip?

What is the length of the springs?

If you are lower than 25", then you probably don't have enough shock travel. At 25" or better you should be OK - especially with such high spring rates. A bit of ride height helps suspension travel so, if you want to experiment as to whether you are hitting bump stops, raise the suspension 1/2"

It's hard to judge anything from your video besides driving technique. I don't hear anything that would 'sound' like you hitting bump stops. Then again, 'hitting' bump stops is not something that would normally generate noise. The bump stop is rubber so if/when the top of the shock body meets it, the noise is typically muffled or just simply not present. Unless your shock is blown. If it is, you may hear loud crashing sound if you hit a sharp bump that would cause the top of the shock body to make *sudden*, high speed contact with the bump stop. However, before that happens the spring will probably need to coil bind - hence my question on spring length. I don't see evidence of either scenario in your video.

The few instances of oversteer that I noticed where caused by your driving technique. So were the instances of understeer. Practice, practice, practice.

Besides shocks, worn pillowballs make a terrible racket and crashing sounds. Those tend to wear out on the FD so that would be the first thing I'd check if your complaint is about clunks and such.