Visit The Dirt Forum for More Information

Author Topic:   Spring Loaded Pull Bar Question?
12modracer
Dirt Full Roller

Total posts: 68
posted June 01, 2004 08:56 PM  
Bought a new outlaw ball bearing pullbar tonight with a 1000lb spring. How much preload should a guy start out with? The car is a three link. Am i in the ballpark by getting a 1000lb spring? Thanks.

udecide66
Dirt Freak

Total posts: 229
posted June 01, 2004 09:59 PM  
I bought the same pull bar from BSB I am using a progressive spring though, I would imagine an 1/8"-1/4" preload is good enough.
I have to advise you on that pull bar, I found this out by experience. The nut you use to adjust preload spins freely. I had my preload adjusted and went out to Hot lap, my brother said he could here a "clunking noise" from the rear end, I immediatley started to check stuff out, I seen the pull bar spring was loose.
apparently when the pull bar is "pulled back" under accleration the preload nut is sitting there able to spin back and fourth freely, without anything to hold it, the vibration alone caused it to loosen up.
I would advise you to put a jam nut against the preload adjusting nut so it don't move.
BSB puts 2 nuts on that end, one is the jam nut for the heim joint and the other is the preload adjuster.
I put 2 nuts on the preload and haven't had a problem since, I adjust preload and then tighten a jam nut against locking it into place. great pull bar, easy to adjust.
Hope this helps you out

udecide66
Dirt Freak

Total posts: 229
posted June 01, 2004 10:08 PM  
I forgot to tell you the pull spring rating greatly depends on the type of track you are running on, Dry Slick, Tacky, Heavy
Afco advised me to try a progressive 600/1050 or a straight 1050 for a dry slick track, it seems to work good, I have an 1/8" of preload and get 1- 1 1/2" of travel
I went from a biscuit type bar to a spring bar and seen a world of difference.
I also run a 3-link

12modracer
Dirt Full Roller

Total posts: 68
posted June 02, 2004 11:16 AM  
Thanks for the input. I was wondering about double nutting the preload nut last night because everything else is. So you made that decision easy. I wondered about trying the progressive spring myself i will try what i got and see how it does and go from there. How did you mount you pullbar with the biscuit toward the front of the car or to the rearend side? I've seen them mounted both ways what is the advantages? Thanks for the reply.

udecide66
Dirt Freak

Total posts: 229
posted June 02, 2004 11:25 AM  
Mine is mounted with the biscuit towards the front of car, BSB says it does not make any difference either way.

STICK01
Dirt Maniac

Total posts: 164
posted June 03, 2004 07:54 AM  
My BSB pull bar had increased its preload by about 10 turns over the course of four weeks...we set the preload and then kind of forgot about it because the car was so good, so i looked at it lastnight and had to take out like 2" of preload!!!

I defiinitely will check it from now on.


12modracer
Dirt Full Roller

Total posts: 68
posted June 05, 2004 07:04 AM  
The car hooked alot better, had more forward bite than i ever had. Only problem was the pullbar only was traveling around an 1". Was wondering what size spring to go to. I ran a 1050 last night. Thanks.

udecide66
Dirt Freak

Total posts: 229
posted June 06, 2004 11:15 PM  
mine only travels an 1" to 1 1/2", with a afco progressive spring, called afco and they said that is enough travel, if you want more go a liitle softer.

Back to the Archives