F1Fan

Hi GTRacing,

You can do much better with a little bit of work on your part. For a street and road course driven car look at Eibach Pro-Kit springs, Tokico Spec-D struts and rear dampers, Steeda's or BMR's adjustable Panhard bar and the H.D. PB bar support brace to locate the PB mounting point better and Steeda's G-Trac brace or something like it from BMR. If you are on the 10" Roush wheels with 275 GS-D3's you can also use a good anti-roll bar kit. I like Eibach's anti-roll bar kit the best, it's the most like an OEM design and is large enough to work without being to big and hurting corner grip and ride much on rough roads and surfaces. Steeda's AR kit is also O.K. but the bracketry is crude, shiney and well finished but a crude design none the less.

That's the basic stuff you'll need to keep it shiney side up. This setup will cost you just a little bit more than the straight bolt-on Roush parts but it will out perform the Roush kit on the track any day and you can adjust the dampening rates to suit the conditions and track type. This is a superior suspension setup to the Roush suspension and you can tune the struts and dampers for excellent comfort on the street or tighten them down for road course use. You cannot do this with any other complete suspension "kit" available.

If you want to get more serious most of the following suspension upgrades are going to improve handling refinement, increase feedback and improve chassis reliability. The way to do this is with better location of the suspension and firmer bushings and joints. Next up is to install BMR's weld-in LCA (lower control arm), relocation brackets to correct the LCA's geometry that was altered when you lowered the car with shorter springs. This improves rear wheel steering caused by the LCAs following their natural arc during cornering and makes the car more predicable in transitions from side to side. It also puts the roll center closer to where it was before lowering and improves your ability to launch hard from a standing start by moving your IC (instant center), back. While you're working on the rear suspension you should also add fixed tubular LCAs and an adjustable UCA (upper control arm with poly bushings or rod ends), to improve axle location for improved grip and handling and more confidance on corner exit. The adjustable UCA give you the ability to correct the pinion angle that was altered when the car was lowered. Don't bother with rear shock tie bars, they are ineffective, add unnecessary weight and cost money better spent else where. The S197 chassis is more than stiff enough to handle these relatively small increases in spring and dampening rates.

The front end is much easier, you've already resolved the biggest issues with the spring and strut upgrades. All you need to do up front is correct the suspension geometry that was altered when the car was lowered and check your bump steer and correct if it's excessive. To correct the front LCA geometry you need Steeda's LCA relocation kit and a good performance shop with a qualified fabricator who can weld and drill very accurately. While you are installing the LCA relocation kit you will have the LCA's out of the car and this is a good time to replace the very soft liquid filled bushings with firmer poly bushings for better wheel location and steering wheel feedback. Check the bumpsteer once you have the LCAs back in the car. It's not an expensive item but it's also not really necessary as the bumpsteer should be minmal. You could also replace the stock anti-roll bar links with the non-comp adjustable links from Steeda to restore the anti-roll bar angles that were altered when the chassis was lowered but this is a minor issue. The adjustability will help if you need to preload the anti-roll bar to tune for a road course. IMO based on the measurements I took with the car loading up the suspension I don't think you need a strut tie bar at the front. There is almost no tower movement under typical cornering loads. A lot of people buy strut tie bars because they are racey looking but on the S197 I think all they do is add 10lbs. to the front-end very high up and and don't do anything usefull. I'd rather spend the $200 on performance parts that make a difference on the track and save the 10lbs.

I hope this helps!


Cheers