BlackShelbyGt500

Hey guys so when i installed my eibach coilover, my car became bouncy is that normal? I did not slam it or anything, i bearly lowered it. Anyways what can i dp to make it not to bouncy?

MELLOWYELLOW06

Not sure if they have adjustments for firm or softer ride, but lowering in general coupled with 20's will make your ride rough.

Andy13186

what do you mean by bouncy? like you hit a bump and it keeps bouncing? if so, that sounds like you have to stiffen the dampers a bit.

BlackShelbyGt500

Eibach 35115.711 Pro-Street-S Coil-Over System this is the coilover that i got.
not just on the bumps but also on uneven road, specially the passengers in the back seat they start bouncy like crazy when ever i go 60 mph on uneven road(freeways). i will try to make a video of it. by the way the bouncing seem to be happening at the rear not so much in the front.

S197 650

Your rear coils have a spring rate of 274 lb/in (for comparison's sake, the Boss L/S rear spring rate is 191 lb/in; you're 43% stiffer in the rear than a Boss L/S).

Think of your car as an upside down, hanging jack-in-the-box. Push the jack up and a soft spring compresses. Replace the soft spring with a hard spring. If you push the jack up now, it also pushes up on the box. This is the extra vertical "bouncing" you're seeing in the back end.

BlackShelbyGt500

umm i dont really get it sorry, so what do i need to do to make the bouncing stop? change the springs? thanks

tr3flip

This ^. You have a Shelby with upgraded suspension. You will sacrafice comfort for performance. Everyone has their limits and you have to find that balance in between. The Eibach Pro Street-S isn't a harsh kit but if you live in an area with terrible road conditions you will feel them more. Can you explain more of the "bouncing" you're experiencing? Is it a slow up and down bounce or is it more of a stiffer, jarring bounce?

The Eibach rear spring on this coilover is progressive from 97-274lbs/in. The stock Shelby spring is linear so there should still be some comfort there.

Old Mustanger

What you are referring to as being "bouncy" is springs being too heavy of a spring rate, this beats the hell out of the car and occupants. Springs that are intended for racing will be stiffer than stock, that is good for the track, but not for the street. Roads are not smooth like a racing track. With stiff springs it is easy to lose control on a bumpy road, it is like a wash board effect.

The FRPP "B" springs are rated at 200# per inch if travel, this should be a good goal, stiffer than stock, but not too stiff.
Find replacement springs that are close to the 200#/in spring rate.

BlackShelbyGt500

i see, so can i still keep my eibach shocks and strut and just change the springs on the rear with a 200#? because i still want to keep the car at the height that it is right now. the coil over i have right now by the way is this http://www.amazon.com/Eibach-35115-7...2008&carId=002 so what spring should i go for at the rear? because thats basically where the bouncing is happening.

tr3flip

The Eibach rear springs that came with your coilover are progressive in spring rate. Meaning they get stiffer as you compress them more. They are rated 97lbs/in at their softest and max out at 274lbs/in. Depending on your load, road conditions, etc, the working rate is constantly changing. I can almost gaurentee the Eibach progressive spring will "feel" much better than a linear 200lb/in coilover spring.