NEHA

I know what we do is a little different than most other road sports so i was curious....When building something new, how do you know what spring rates to use? Does anyone have any good books to suggest for suspension setups? Then add on personal opinion for the hillclimbs. It seems that maybe super stiff isnt the way to go at the hills. Comments, suggestions?

I know if you drink too much beer and don't exercise you may need stiffer springs to prevent bottom out.

Even the legendary Carroll Smith was vague on spring rates. In his "Engineer To Win" (some of the best books available on racing are the "____To Win" series by him) he simply says picking spring rates is to complex for a book...

Not much help, huh?

My advice based on my experience with the GTI: Firmer than stock and softer than road racers like. I ended up with what I use almost by accident. When I was building the GTI as a rally car I went looking for advice and ended up at Shine Racing. They are mostly road racers but they did rally Rabbits. The springs they suggested for me and rally were about 3/5 what a road racing GTI would use. e.g. road racing the second gen Golf they ran around 500 front and they suggested 300 front to me. Turned out to be too stiff (and too short) for gravel rally where around 225F was better, but the 300F/200R they sold me does work quite well for hilllcimbs. BTW I have no clue what a stock GTI uses for front springs but I think they are between the 225 and 300.

so i think someone arready suggested spring rates are your last concern. build the car first. it's gonna be fun watching you ride a set of springs up the hill.

First, you need to measure your suspension geometry, to determine the factor between spring rates and actual wheel rates (which also include swaybar rates) Then look at your ride height, bump stops, etc, to determine desired travel.

Sum of wheel rates=curb weight/desired travel, with 75% of roll stiffness apportioned t0 the front. (assuming little banking in corners and approximately 1 G cornering, no wing load) - And this is only a starting figure, to be tuned for driver prefrence!

Does what you have now seem too much-or too little?
Put a wire tie on you shock shaft-see how much travel you get. 3/4 to 7/8 of travel is good.

I did extensive research on what to run on my old Rabbit.... spend countless hours. Then I called Bill Rutan and got an answer that worked for me. My point is talking to someone with the same car and seeing what works for them. Of course, that means that someone would have to do the trial and error thing to figure it out for everyone else.

John R. seems to have a good start on setup, naturally followed by tweeking. But, I'm not the technically minded sort.... either it feels right or it doesn't.