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Ron Stygar Carl Buckland Dale Beuning Forums Help
From digest.v6.n860 Tue Jul 8 19:37:17 1997 I just have one warning about springs. Don't buy unknown, cheap springs, such as Intrax. I have used a set on an E30 M3 and they did more lowering than stiffening. The rear springs were too soft, and the car would bottom with four people and anything in the trunk. Any stiffening in the front was the result of the Bilstein Sports. Buy from a reputable company that knows what your car is and is supposed to do. From my experiences, the rear needs both more rate and more damping than Racing Dynamics, Intrax, or stock springs and Bilstein sports offer. However, if you only want a more stable, aggressive feel on the street, any of the better known spring companies sell excellent products. The added performance comes from _both_ the stiffer rates (mostly) and the lower center of gravity (CG) (to a lesser extent). Many cars also get added negative camber by lowering the suspension. For track _racing_ purposes, talk to the companies that have done it for years. Experimenting by youself, even if you do know what you are doing, is more expensive than paying a premium price at a well known company for their kits. You not only pay for the parts, you also pay for the development time that they spent putting the package together. A couple of things, though: Don't compensate for weaker springs with a bigger anti-roll bar. Granted, the stock anti-roll twig on the M3 is a little small. I'm using the 19mm from the Suspension Techniques kit. Too much anti-roll creates unwanted excess weight transfer to the outside wheels. Believe it or not, in racecars anti-roll rates are often used to balance the car versus counteract body roll; they are not as stiff as one would think. Also, it is not a good idea to mix different brands or types of dampers, e.g. Konis and Bilstiens/KYB/Carrera, etc. Do not mix gas-charged dampers with non-gas charged, e.g. Koni (non-gas) with Bilstein (gas). The M3 is currently getting a coil-over conversion in the rear with custom vavled Bilsteins F and R for better balance on any type of track.
James Muskopf |
