Are you NUT'S or just stupid?!

[hpmaster]

Just got off the phone with a friend of mine who is an active LM racer in another part of the country. I thought it was common knowlege to NEVER run an aluminum drive shaft with a ballspline. Read this.....
He was telling me of a local racer in his area that believes that adding pinion angle to his car, in what direction I do not have a clue, will add drive off. Now that is only half the story he is doing this to a car with a Bert ballspline while using an aluminum drive shaft. So far this year he has broken a drive shaft yoke and just last week destroyed the Bert and then ripped out the X member out of his chassis. He said the guy was looking for a drive shaft earlier this year and was told NOT to run an aluminum drive shaft but did anyway's and now destroys the car and transmission. Ok how many guys run aluminum shafts with ballsplines? I sure have my own thoughts about this but what are your's???

[save the racers]

Our driver back in 03 ran one all season and he raced for a living. It was a shock to see him do that but never spit one out. I think the guys who have everything working good feel confident in them. Saw moyer Jr break one at Kankakee summer nats race one year and was suprised to see he had one. I'm wondering if some of the bigger name guys that run them dont get a sponsor kick back on them. I have a feeling our driver was and i can almost bet moyer jr was.

[phenom08]

I would sit out a few weeks before running aluminium or steel and I don't even run ball spline. Brinn here not worth the risk of life altering injury.

[Matt49]

I don't even run a ball spline but I still run CF drive shaft and it isn't because I have an endless budget. It's just the smart thing to do. If I were running a race track it would be a rule that if you have a ball spline tranny you, then you must have a CF drive shaft.

[hucktyson]

How many 10k plus races have been lost by carbon fiber driveshafts inexplicably failing ??? Simple don't run a ball spline and run an aluminum shaft and don't fall out of races ...

[fastford]

I have to agree with you hucktyson, to the original poster, your friend probably trying to run way to much downward pinion angle, a person will start by adding a little angle, say a couple degrees and bam, he feels traction gain in the slick, so he keeps adding and finally, no shaft will stand it, seen it happen a lot over the years...jmo

[drtrkr244]

That's an old school way of decreasing torque to the rear wheels. A lot of supers are running dual ignitions with one set at 4-6 degrees less timing.

[DLM06]

How does pinion angle increase or decrease torque or traction?

[LITE-INN]

Are you NUT'S or just stupid to some the answer would be yes

[drtrkr244]

Anytime you get front and rear driveline angles to far apart you lose driveline efficiency. Its been proven on chassis dynos many times. I seen dyno results where a crate car lost 10-14 hp.

[hpmaster]

Yes you can kill performance with stupid driveline adjustments. You can also kill ujoints, driveshafts, transmissions rearends and if you try hard enough you might just kill yourself, but we always need a few volunteers to prove Darwin correct.

[HuckleberryB4]

So 6-8* of pinion angle is recommended. How much is too much for a drive line to handle?

[hpmaster]

Ok the idea is that when under power the drive shaft and pinion are in a straight line. According to Spicer, the inventor I believe of the U joint, the max OPTIMUN working angle is less then 3 degrees of angle away from straight under power. Now here comes the argument, according to Spicer the total angle, 6 to 8 degrees, is the angle of the drive shaft ADDED to the angle of the pinion. So now I wait for the disagreements to begin. Here is the Spicer link.

http://spicerparts.com/anglemaster/measuring-angles

[Matt49]

It's fools gold.
Increasing the pinion angle decreases drive train efficiency which decreases the power to the rear wheels. This helps decrease wheel spin for a driver incapable of doing it with their right foot.
Run the proper pinion angle and learn how to drive is the best answer I could give anyone.
If that's still a challenge, disconnect your secondaries or change the motion ratio of your throttle linkage. Both better solutions than trashing u-joints and even some of the best do it.

[hpmaster]

It's fools gold.
Increasing the pinion angle decreases drive train efficiency which decreases the power to the rear wheels. This helps decrease wheel spin for a driver incapable of doing it with their right foot.
Run the proper pinion angle and learn how to drive is the best answer I could give anyone.
If that's still a challenge, disconnect your secondaries or change the motion ratio of your throttle linkage. Both better solutions than trashing u-joints and even some of the best do it.

All very true. Big motors and a wrong camshafts are guilty for all sorts of drivabilty problems too. Set the driveline correctly and then fix your other problems.

[drtrkr244]

It was explained to me that, under full rearend wrap-up, you wanted a small degree difference between front and rear u-joint angles. That keeps the needle bearings loaded so that they constantly are turning and not wearing in one spot.

Plain and simple.....the chassis mfgr's know this, that is why they tell you to run a certain pinion angle!

[fastford]

no one here is wrong with there thoughts on this, but there's a lot of other variables to consider, especially with the amount the lift bar or pull bar travels. I have ran 6 degrees of actual downward angle on the rear pinion with no problem, so I guess spicer would call that 12 degrees, of course this is static, under full load it might not be but 3 deg or 6 according to there formula, one thing to be careful of when playing with pinion angle and a lift bar type car is what happens when braking , you will gain angle with a 6th coil set up and if your on the ragged edge it don't take much.

[LM14]

The IMCA sanction does not allow anything but a steel or aluminum driveshaft. I don't have a problem running one with a standard style yoke like we did on Brinns but wouldn't even look at a ball spline if you couldn't run fiber.

SPark

[LITE-INN]

carbon fiber is sasafer correct so why not use one

[lovinlatemodels]

I have always run a steel drive shaft with a ball spline made from Wiles and never had any problems did this for 13 years of racing maybe it is wrong set up and in proper maintenance that's is causing the problems I know some people like to stretch there equipment longevity way to long.