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Author Topic:   spring loaded pull bar Q?
madnik18
Dirt Full Roller

Total posts: 40
posted September 08, 2005 11:16 AM  
i dont know anything about these.. how does the angel effect the car?
what does preloading it do and how do ya do it?
thanks in advance,

FlyNLoIMCA17
Dirt Forum Champ
Total posts: 753
posted September 08, 2005 07:12 PM  
You preload the spring by tightening the nut that is against the spring plate. What that does is compress the spring and increases the rate slightly and removes any "slack" in the pull-bar assembly.

Increasing Pull-bar spring rate will provide more "instant" traction but can lose its bite on down the straights. You can go too far on the spring and have almost NO traction anywhere. The basic starting point is a 1050 spring or a progressive spring like Afco sells.

The downward angle of the car does basically the same as the spring rate. The more downhill angle in the bar the more instant traction, but just like a spring you can go too far and the car will lose bit on down the straights. The basic starting point for say a 1/4 mile track is around 15 degrees downhill.

Hope that helps!

FlyNLoIMCA17
Dirt Forum Champ
Total posts: 753
posted September 08, 2005 07:18 PM  
I forgot something else LOL!

The basic starting point on spring preload is 1/4"

Also when finding the right pull-bar spring always check how much travel the bar is getting. Most bars have a slide type travel indicator with and o-ring on it. Now as for how much travel you need?? This has been discussed on here many times. Some say they run good with 1-1.5" of travel. I'll tell you my experience. I run an Afco progressive spring and I get 2.5" to 3" of travel. At one time I was getting 1.5" I made some changes and started getting around 3" and I could really tell a big difference in traction. The car bit a lot harder with 3" of travel. So you just have to make your own choice on that LOL!!!

madnik18
Dirt Full Roller

Total posts: 40
posted September 08, 2005 08:44 PM  
thanks for the info.

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