What is the correct pinion angle for dirt track racing? Another question is my driveshaft is not flat in the car it runs downhill from the tranny to the rear about 2 1/2" so do i have to take that angle into consideration also or just the pinion? Thanks steve
246 people looked at this and nobody can even give me there opinion?
well 247 offers this, though I'm new to dirt tracking:It seems to me, unless the driveshaft is really short, 2 1/2" drop isn't real excessive. With that in mind, I believe you would want to try to match the angle at the trans end to the axle end, in other words having the trans and axle yokes parrallel. I think this is how most vehicles are set up.If you end up pointing the pinion up too much, you run the risk of not enough lube on the pinion bearing. I am told though that in dirt tracking, you want to "overfill" the axle anyway to ensure lube to the inside bearings. I read somewhere once about using a gallon of fluid in the axle.Again, I am new myself to dirt tracking in anything other than Bomber classes, so I am learning myself. Hope this helps!
Thanks so much i'll keep that in mind.
i find that you can not measure drop and get an accurate pinion angle as it changes from car to car. unless built on a very solid jig each car will have variances, no matter how much you think you every thing exactly like the last one that worked. an inexpensive angle finder works very well placed right on top of the third member housing. i have run as little as 6 degrees and as great as 14 degrees.i run a 4 cyl toyota with a 22re putting out around 250 horses through a 2 bbl carbeurator, on dirt. with about 10 degrees in can pull the left front wheel off the ground about a foot in a full bodie ministock and a fairly heavy track
Thanks alot for takeing the time to reply
correct pinon angle depeneds on the car use an angle finder. i would not go passed 8 degrees or you will start eating u-joints 5-7 works well.
My driveshaft is at -10 degrees from the transmission to the rear so i set the pinion angle at +10 degrees also.I read in circle track that the u-joints should be at the same angle at one end as the other? Don't know if it will work but were going to try it. Thanks Steve
Both ends of the driveshaft need to be same angle if you expected u-joints to last any time at all. I'd run no more than 6 degrees angle at either end, (and pinion should be tilted downward for bear lube). An old fashion protractor will do the job of angle degree finding, and remember car should be checked at curb weight not jackstands.
OK, Pinion angle. I figure your running a gm product.Pinion angle above 0 (zero) is bad. in forward, the pinion gears tries to climb the ring gear. That energy is transferred to the diff housing, which tries to raise up. That energy is then tranfers to the tires and causes the rear tires to bite harder in the dirt. The best pinion angle is between 3 and 7. degrees. To much angle can break the u-jiont. There is alot more that plays into pinion angle. Example The type of bushing, Trailing arm's angle, rear spring rate, shocks etc. That why you always make little changes at one time.
Thanks alot for all the information!