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New shocks / springs for street track setup?

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Tried to order H&R coilovers from tire rack. They quoted me about 3 weeks from Germany. A bit too long for me. I ordered koni sports instead and I already received them. I went with the gt500 style as I got a good deal on a steeda upper mount for that style. After speaking to the rep with Steeda, I went with boss comp springs. He said they were pretty close to the reg comp springs. Maybe less lowering overall. They were the last s197 spring they developed. Def recommended a stiffer shock package than stock GT.
There are other resellers of the H&R RSS package. Kenny Brown Performance, Lethal Performance, Maximum Motorsports and others.
 
109
25
Exp. Type
HPDE
Exp. Level
5-10 Years
New England
Figured I would report on my setup. I went with Steeda Boss comp springs, Koni yellows and steeda uppers.

The steeda upper mounts (I went with 05-10 style) seem to work well for a street based car. Zero NVH, and easy to set adjustments. They don't offer a ton of camber adj, but enough for what I am doing.

Koni yellows are what they are. I have had 4 sets on various cars and they all exhibit the same characteristics. Low response, soft compression with endless rebound control. They struggle to both maintain ride and control at the same time. However they are a low cost damper, and for what they are offer a very good return. They are a big step over stock and can control very aggressive spring rates.

The Steeda Boss springs provided close to the expected drop on my car. .5" front and 1.75" rear. My car had a pretty big rake to start, but on the boss springs the rear ended up a little lower. My target was slightly higher in the rear so I had to add a thicker spring isolator in the rear. Ride height is now perfect.

Spring rates overall are surprisingly soft. With the Koni's at the lowest settings, there is zero ride penalty when compared to stock. However with that setting once you hustle the car, the handling becomes sloppy. Turning up the konis tames that. But then the suspension starts to fall and crash. This occurs at around .5 turns out from full soft. This plus my experience with konis, tells me the spring rates are too soft. Maybe not the total rate, but at least the initial rate.

At the track I can be more aggressive with the damping, but then the suspension has a tendency to pack down. I think the real solution is a stiffer spring with a straight rate. Not sure what else is out there that wont drop the car more. I am at about 15-15.5" fender to hub and want to stay there.

Overall this is a decent street setup and will see what it can do at the track. I think it can even be better without too much investment.
 

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