Short Pullbar

[greenmod]

I am looking for some info on where to start spring rate wise on a short, bsb pullbar in a 602 crate mod on a flat 1/2 mile track. Thanks

[Team EERC]

The best way to go is to get the kit to convert it to the three way comes with a spring couple laser cut washers a spaced and bushing. If you want to stick with just a spring go with a 1200. All of that does depend on where it's mounted, rear end placement can change the reaction drastically.

[dirtrace09]

Why not run a progressive spring? Is it better to let the second stage act as the progressive part?

[Team EERC]

Progressive springs are have proven to be very inconstant in testing. Also they generally start off to soft and take to long to build rate due to the design process behind manufacturing progressive springs. Anytime on coil touches another coil (coil bound) it stresses the spring and a pull bar will do this many times per lap. That stress will change the characteristics of the spring. By using the two stage system you can tune the spring rate, preload, bushing and spacing more accurately. I have sold a lot of these and install them on all of our cars always had great feedback Feel free to give me a call to get a better explanation if you would like.