Stiff springs: How stiff can I go?

[thechadzone]

I just finished replacing the sway bar bushings, control arm bushings, and upper/lower ball joints on my car, so next are its shocks & springs. I'm in the process of stripping my car down to street racer spec, and part of this preparation is a suspension system similar to those found on track day cars (600+ & 200+ between front & rear).

I'm wondering how stiff my springs can be before I'd have to reinforce the shock towers, and/or other areas of my cars chassis. Maybe none? How stiff should my shocks be to handle track car spring stiffness? The car's structure is sound, and free of rust. My daily driver is a Civic EX, and when I'm feeling sporty I drive the Alfa. When I'm feeling balls-out I take the Fiat, and it rarely goes anywhere except for dubious adventures around downtown, and local highway trips. I don't outright abuse the Spider, but I really enjoy driving it right at its limit.

Thanks for the responses.

[engineerted]

I'm wondering how stiff my springs can be before I'd have to reinforce the shock towers, and/or other areas of my cars chassis.

The Shock towers are plenty strong, no need to reinforce. The issue you will have is with the body itself, with out a full roll cage the spiders body is a wet noodle and the body will flex and twist itself into a scrap pile. Race tracks are flat and smoooooooth and don't see the impact of pot holes or miss match joint lines, so 600# is going to be a tad much for a street going car. ~400?

That being said: Koni Yellows on full hard for the front with 600-650#springs, Rear Koni or KYBs full soft with 175-250# springs, dont for get the rear bar and weld up the diff for some real fun!

Ted

[thechadzone]

Thanks, Ted. I was hoping that I'd get a reply from you. That was exactly what I was looking for.