Perfromance, real, not so real, balance in the middle?

[03whitegsr]

If you aren't going way up on spring rate, the seperate rear spring is less of an issue. It's when you start using a spring rate of like 900lb/in where the weight of the car only compresses the spring 3/4" or so. Now all you have is ~1.5" of droop travel at the tire before the spring is rattling around.

My issue with the lowering springs, the rates are too soft and they lower the front a lot more then the back. I do not like the high rake look that is common on this particular car.

[wolferj-RIP]

Ok, I am going to wander into this discussion with a question...

I am running a D2 coilover setup with a 6 cyl swap. (Don't ask the spring rates, IDK)

When I have had the rear height adusters removed (springs only), I have had understeer issues on the track, while running 255/40/17 R1's all around. I decided to raise the rear some (about 1") for my next HPDE which is a 5 mile course with 25+ corners and multiple elevation changes (Thunderhill with the new addition).

Understanding that I have gone from a basic lowering spring/'Bilstein combo (way to soft all around) with "Trackable" tires to my current configuration (coilovers & BFG R1's), what do you think I can expect?

[AnuketTi]

Originally Posted by wolferj

Ok, I am going to wander into this discussion with a question...

I am running a D2 coilover setup with a 6 cyl swap. (Don't ask the spring rates, IDK)

When I have had the rear height adusters removed (springs only), I have had understeer issues on the track, while running 255/40/17 R1's all around. I decided to raise the rear some (about 1") for my next HPDE which is a 5 mile course with 25+ corners and multiple elevation changes (Thunderhill with the new addition).

Understanding that I have gone from a basic lowering spring/'Bilstein combo (way to soft all around) with "Trackable" tires to my current configuration (coilovers & BFG R1's), what do you think I can expect?

James - I'm chiming in with my limited knowledge. I would imagine that with the height adjusters removed on the rear - you may have created two scenarios:

1. The rear was softer? Thus in turns your car would squat on the outside wheel pretty much causing the front to ride higher than the rear and also cause the car to push creating under steer.

2. With the rear adjusters gone, could there have been some degree of reverse rake going on? I doubt that though as I have seen your car. If the theory of reverse rake were in play, then that means again the front end was sitting slightly higher than the rear and would induce under steer.

Have you raised the rear using / replacing the rear adjusters? Whichever way you have done it, I would think you would cut down or eliminate the under steer issue. From my days or racing bikes (May not apply to cars), I know that we would lower the front end to get faster turning and eliminate understeer or the tendency for the bike to "wash out" on the front end on maximum lean turns. The downside was that you had a very twitchy front end.

Just sharing my thoughts - I will probably get corrected shortly.

[wolferj-RIP]

Michael;

I put the adjustable rear spring perches back on the car. I also adjusted them up some, so I ended up raising the rear about 1" total. I doubt I actually had "reverse rake", but I do now have a minor forward rake. Hopefully this will give me a more neutral steer, but it may be too much. I plan to actually adjust the height once or twice during my track day to fine tune the ride, so this will be a day of experimenting.