Suspention issues, Advice needed

[Fatboy 18]

Hello, OK here's my problem

Car 2000 GTS, stock Koni suspension.
Wheels 18" CCW Classics.
Tires Michelin PS 2s 335 x30 x18

When I 'push on' in the car at the track or into a fast corner, My rear suspension compresses too much that the outside edge of the tire is getting slightly shaved by the top lip of the wheel arch The CCW Classics do stick out slightly more either side of the rear wheel arches so I know this is a factor

When the car is stationary with no Driver I have about 3 inches of clearance between the top of the tire and the wheel arch. Im not a heavy guy, I'm just over 6FT 1 and 190lbs.

What Im worried about is I'm in the process of fitting an Autoform Roll bar with dual side bars. Now this will also add weight towards the rear of the car. So what do I need to do to the suspension to stiffen the springs?

Ive tried reading through the workshop manual, but its a bit of a minefield for me, If Im right you can adjust the damper inside the spring but I think my problem is with the actual springs? How do you guys get on with spring lowering caps? Surely you must catch the tires?

 

[steve911]

The issue isnt necessarily ride height but spring rate and sway bar size. It sounds like there is quite alot of body roll/weight transfer to the outside rear corner of your car when tracking it. The only way to eliminate it is to up the spring rate and even upsize the bars.

Steve

 

[Fatboy 18]

Thanks Steve, I thought that might be the case

So does anyone else have this problem? If so, what Springs have you gone for?

 

[steve911]

Thanks Steve, I thought that might be the case

So does anyone else have this problem? If so, what Springs have you gone for?

I have a Gen 3 and I am running 1110 rears and 700 fronts with solid sway bars (stock configurations)

 

[GTS Bruce]

On a gen 2 like yours I use eibach's all around. They drop the car

You must be registered for see images attach

about an inch but are listed as 10 % stiffer. No rub problems. Hope this helps. GTS Bruce

 

[Fatboy 18]

Thanks Bruce, love the pic Your rear wheels are much further inside the arches than mine!

 

[mjorgensen Woodhouse]

If your shocks have nitrogen charged canisters you can up the pressure 20-25 psi and probably reduce the rubbing. If the car has regular off the shelf Eibachs then with the added aero you are probably not stiff enough for the added suspension compressing mid corner. As stated above time for stiffer springs.

 

[MTGTS]

The stock Koni's are rebound adjustable, not compression so that won't help you.

If you have 3" of static clearance and you are rubbing something is moving around to much or already broken. Check your control arm bushings, swaybar bushings, shock mount bushings, balls joints, wheel bearings, endlinks, toe links, everything. Make sure your shocks are good as well. Jack the car up and see if you can wiggle a rear wheel. Should have 0 play.

I would upgrade your springs anyways if you are doing so track stuff as it will make a difference. The stock rear spring rate is 450and is linear.The Eibachs start at 457 and go up to 800 progressively.

 

[Fatboy 18]

Thanks for the input guys. The car has just passed its annual MOT Government test where they look under the car test the brakes, check suspension, lights, seat belts ect ect.

The only thing that was noted on the rear suspension was one of the rear sway bar rubber boots was missing! I ordered 2 new Sway bar drop links later on the same day from VPA, They are being shipped at the moment


Now sorry to say but I cant afford thousands of dollars for new shocks, can I get upgraded rear springs for the stock Konis? If so could someone point me to the best Vendor for these?

Thanks Mark.

 

[MTGTS]

when you say stock Koni's do you mean the ACR Koni's or the Koni blues?

We don't have MOT over here so I don't really know how intelligent an MOT inspector is. I would jack my car up and get in there and have a look for myself.

Hyperco is a company that can make any spring you want. http://www.hypercoils.com/

 

[Fatboy 18]

The Koni Blues The MOT inspection is pretty tough on safety, they have a metal plate that you drive onto and its moved by hydraulics, left to right and backwards and forwards to check for worn bushings! Its ******* the suspension!

 

[MTGTS]

The Koni Blues

You should be able to find a set for pretty cheap if it turns out they are bad. I think I sold mine for like $400-$500.

 

[Fatboy 18]

Found this video which is part of out MOT test, its a bit cheesy but you get the idea

http://www.youtube.com/watch?v=JTrXzVxCjbs

 

[MTGTS]

Found this video which is part of out MOT test, its a bit cheesy but you get the idea

http://www.youtube.com/watch?v=JTrXzVxCjbs

Yes, but I doubt they do that on the rears

 

[Fatboy 18]

They do all 4 corners!