Pull bar spring preload

[washeduptoo]

Usually run biscuit pull bar but trying a spring pull bar during the heavy track conditions. Lets see if I got this preload down to what its doing. If its a 1200 # spring, that means it will take it 1200# to collapse it one inch? So if your preload it a 1/4 inch, what are you doing exactly. Seems as you compress spring more, the more pressure it would take to initially start it compress? Is this close or if someone has an article on this. Thanks for the help.

[dirttrackrocker]

Anybody??? I'm interested too... Went to a spring pull bar this year. Running a 600-2000 progressive spring. What effect does preload have on what the car does?

[racinjj]

I run a oneway pullbar with a 1200# spring on IMCA tires and start with 3/8" preload. You are on the right track that with more preload it will take more force to start compressing the spring. Basically you are delaying the spring compression and putting more power to the tires instead of absorbing it with the spring. You will want less preload or a softer spring as the track gets slick to avoid shocking the tires when you get on the gas.

[washeduptoo]

Thank you very much for the help.