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.

[hpmaster]

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.

Funny you mention a steel drive shaft because I was called by my friend in our weekly post racing call this morning and he said that guy has put a steel driveshaft in now.I was told this guy has broken 2 drivelines in one month. The first was a driveshaft the second was the yoke/output shaft of the transmission. This indicates to me a very likely improper driveline angle, as breaking a driveline twice in a month is most likely more than bad luck and at very least not inspecting all parts the first time in my mind. I hope that steel bad boy doesn't get loose and fly around.

[hucktyson]

I don't understand why people run ball splines ... Plenty of Crown Jewels are won without ball splines and the potential driveshaft tearing the car up issue .

[drtrkr244]

I have never broke a driveshaft in 25 years of dlm racing. I consider some of that is luck but the majority is good maintenance. Also, I only used Spicer u-joints not the el cheapos at the local auto part stores.

[fastford]

I don't understand why people run ball splines ... Plenty of Crown Jewels are won without ball splines and the potential driveshaft tearing the car up issue .

I never understood it either, I looked at them when they first came out and realized how much extra maintenance was involved compared to the little performance gain I could see and have always stayed with the regular trans and never had any problem....knock on wood....

[LimitedLM06]

What exactly is the safety benefit of a carbon fiber drive shaft? Is the strength? Of will it shatter if it comes out? I got one with my car but assumed it was more for rotating weight.

[LimitedLM06]

So what is the safety advantage of running a carbon fiber driveshaft? I got one when I bought my car, but thought it was for reciprocating weight.

[wisdirtfan]

If it breaks it will shatter instead of hitting your elbow and destroying the interior the x the loop etc. Basically tearing up everything in its path. We don't run a ballspline and broke a lift bar this year and it destroyed the deck the oil cooler the fifth coil and the shaft even managed to smash the oil tank on its way out so ya ballspline=carbon fiber shaft.

[AmickRacing]

Here's an interesting video. I knew about this a little bit, but watching the video helped it make a bit more sense...

https://www.facebook.com/photo.php?v=470937339716400

[keeks]

That video is serious voodoo that I never would have thought about. wow! Good info.

[7uptruckracer]

Carbon fiber is always a good idea. So what it breaks and you maybe lose a 10k race. This is a 10k hospital bill. Yoke broke, and the shaft became a can opener and propeller of destruction until I locked the rear brakes up. Tore everything out and apart from the battery in the back to the cables of the starter, to the wiring right out from the (not a nice word)(not a nice word)(not a nice word)(not a nice word)pit, It wraps anything up it snags and the only thing that saved my life was the battery cable tethered it so tight that the cable actually twisted and imprinted deep into the driveshaft tube

[powerslide]

I never understood it either, I looked at them when they first came out and realized how much extra maintenance was involved compared to the little performance gain I could see and have always stayed with the regular trans and never had any problem....knock on wood....

I'm not sure what you are saying is more maintence on them. We used them with an Alum shaft back in 03 and just cleaned greased them after 10-15 races. Not anymore work than a regular trans. But i agree i would never personally own one, looking back i'm suprised he did and it may of been because of a sponsorship deal not totally sure.

[fastford]

I have never ran one powerslide, but was told they really needed cleaning and checking more like every 2 to 3 races , which consisted of pulling shaft and taking the slip yoke apart, don't know for sure, just what Ive been told by several people.

[hpmaster]

Just got a pic sent to me of that broken ballspline. This is the second failure in less than a month, the first was a broken driveshaft yoke I am told. After looking at the picture I can't see how a steel driveshaft is going to solve anything? If you do not fix what is breaking the driveline all a steel shaft would do is have a bigger bat swinging around when it breaks again!

[hpmaster]

Just had a PIC of the first driveshaft that was broken sent to me. Seems the guy posted them on a FB page I am told.

[save the racers]

Probably broke the yoke because of the first failure. Didnt check it out just put a new shaft in

[zeroracing]

I made that mistake, broke a torque arm, broke the driveshaft, replaced it and promptly broke another, rear yoke had cracked and was destroying U-Joints. I finally learned my lesson...

[davis2902]

Ask Jeremy Clements about running a steel drive shaft!

[hpmaster]

Ask Jeremy Clements about running a steel drive shaft!

On July 24, 2004, Jeremy suffered an injury that threatened his racing career while running his No. 51 Late Model at 311 Speedway in Madison, NC. The torque arm broke under his car and sent a steel driveshaft piercing through his (not a nice word)(not a nice word)(not a nice word)(not a nice word)pit, almost removing his right hand. Initially doctors predicted that he would be lucky to have any movement at all in the hand. Jeremy underwent 8 surgeries and months of physical therapy to regain use of his right hand.

Just if you think it NEVER happens or only rare read on


(not a nice word)(not a nice word)(not a nice word)(not a nice word) Barton moved his foot. He felt no pain.

Then he touched his hip. He found no blood.

Except for a bruised hip, Barton survived the first broken driveshaft of his 36-year dirt racing career.

After breaking away from his Super Late Model, the steel driveshaft -- a mechanical device shaped like a long, thin tube that transfers engine power to the rear of the car -- broke through a protective aluminum plate and crashed into Barton's seat.

"All I felt was that thud," said Barton, of Ashville, N.Y.

But his injuries in that 2008 race at Stateline Speedway could have been much worse.

"The deadliest thing on the car is the driveshaft," said Late Model racer Scott Johnson, a Wattsburg native. "(The) most bodily injury that you're ever going to get is from the driveshaft unless it's a total disaster rollover. The only thing between you and that driveshaft is one (safety) hoop and that little bit of aluminum (and) steel that's supposed to stop it."

Racers consider that thought when they decide between steel, aluminum and carbon fiber driveshafts.

Then they answer one question. What's more important -- cost or safety?

Steel and aluminum driveshafts are cheaper -- $100-$275 compared to $650-$750 for carbon fiber.

Steel and aluminum driveshafts are more dangerous. A steel driveshaft broke Late Model veteran John Lobb's elbow and severed an artery in his arm during a 2004 race at Eriez Speedway.

He missed two months of the season while recovering from those injuries. Worse, he lost time and money at work.

Last season, he broke two carbon fiber driveshafts in consecutive races. They disintegrated instead of crashing into the (not a nice word)(not a nice word)(not a nice word)(not a nice word)pit. He wasn't hurt either time.

"It's a pretty good insurance policy," said Lobb, of Frewsburg, N.Y. "Yes, it's $500 more. But can you afford to be off from work for several weeks?"

North East native Terry Akerly, a Lake Erie Speedway veteran, has a heavy duty driveshaft -- similar to what are found in trucks -- in his SportMod.

No more regular steel for him, not after barely escaping injury in a 2007 Street Stock race.

The driveshaft twisted and broke before ripping a big hole in the floor.

"That one (isn't) breaking," he said of the heavy duty driveshaft.

Barton still uses a regular steel driveshaft.

"It's probably foolish," Barton said, since he isn't certain why his team hasn't changed to carbon fiber.

Perhaps it's a cost issue. Perhaps his team still believes driveshafts don't break because other faulty parts cause them to break. Another broken part caused his driveshaft-related mishap last season, he said.

Other drivers point to wear and tear as the cause.

Akerly's broken driveshaft was the original on his 1977 Street Stock.

"They can only take so much for so long," he said.

Driveshafts face a tremendous amount of horsepower and torque as they spin. Johnson's motor turns at 9,000 rpm in a race. Barton's motor surged from 8,500 rpm to 10,000 rpm once the driveshaft broke.

"I know it's wheeling," Johnson said.

Some drivers never discover the cause. But they all know "they're very dangerous," Barton said.

A week after Barton's incident, Johnson's team purchased a carbon fiber driveshaft. Two weeks ago at Eriez, Johnson remembered why he has one.

He watched Late Model racer Ron Bem, of Union City, suffer multiple leg bruises from a broken driveshaft. Afterwards, Johnson's team found it bent into a U-shape and snapped the safety hoop.

Driveshafts are a part of teams' weekly inspections. LES officials require thorough inspections, including driveshafts, before allowing cars on the track. But finding potential problems is challenging. Even with visual inspections, the smallest fractures that lead to breaks are difficult to detect.

So every weekend on the track, "There's always that thought in the back of your mind," Lobb said. "Nobody wants to get hurt."

[andy16]

i always ran a driveshaft loop that is round, not square half a.. ones that come in the car. i took a weight clamp and a 2 inch by 1/4 aluminum strap drilled a hole in one end of the strap bent it over a 5 gallon bucket and did some hand-vise massaging then when u got a nice circle put a 1/2 bolt thru both holes and mount it on the x member near the front of the driveshaft so if it does come apart it dropd in the circle and just sits there and spins. no more tor up x members no more tore up drivers and it maybe weighed 3 lbs and cost 25 bucks a 1hr of time. i never had a d/s fail but i always ran that. dont know if it woulda held up or not but i felt better anyway

[hpmaster]

Take a look.

[Lizardracing]

One thing that Andy hit on is an absolute. No one seems to like to talk about the stupid cheesy worthless loops put into cars these days. With two loops or better yet a tunnel including and not limited too, extra support on the drivers tub near the DS like 1/8 aluminum for example, DS injuries could be dramatically reduced to almost never instead of common.

I don't want to hear anything about the weight penalty either. It's centrally located and has the least effect on handling.

[grt74]

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.

you sir are a very lucky man playing with your life,and please don't take this wrong,I'm not dogging you in any way,
guys heres the facts as i know them,we run carbon fiber drive shafts in all of our late models,crates and supers,we haven't had any and i mean zero failures with all having ballspline trans,now as far as any ballsplines failing,everyone that I've seen fail has been from lack of maintenance PERIOD,
TOO EVERYONE OUT THERE PLEASE AS A RACER, OWNER, AND DRIVER,PLEASE AS YOUR FRIEND FROM EXPERIENCE USE A CABON FIBER DRIVE SHAFT FOR ANY AND ALL BALLSPLINE TYPE TRANS,YOUR LIFE IS WORTH 600-800 TO YOUR FAMILY AND FRIENDS,i have had a very good friend of mine that the drive shaft came in the (not a nice word)(not a nice word)(not a nice word)(not a nice word)pit,he was VERY lucky,it broke his pelvis,almost broke his leg,and took some time to get over,not to mention beat the hell out of the seat and how it didn't get his arm i don't know,GUYS THIS IS A HUGE SAFTEY FACTOR,too all good luck and PLEASE use common sense and be safe out there,all of the testing on the driveshaft(the oldest one)its been through 3 cars,a 430,a 415,and a 450,with plenty of power,all i can speak of is from my experience and there it is,ALL FACT,i forgot to mention,it was a standard trans but the tailshaft housing broke(rubbins racing)yoke fell out and the rear end was still hooked up and rotating,like i said HUGE SAFTEY FACTOR and should be mandatory for all ballspline type trans

[Kwhardage]

We had a chain of events destroy the (not a nice word)(not a nice word)(not a nice word)(not a nice word)pit of a car and nearly destroyed me. We were experimenting with a pull bar, and found out that we didn't have near enough braces to hold the mounts in. It pulled the cross tube that the mounts were attached to (factory installed tube) clean out of the car. In doing so, it pushed the driveshaft into the transmission and broke the bellhousing in half. The transmission came out and the driveshaft went to work on me and the car. Not 100% on what all hit me, but I got it in the shoulder, elbow, and even had a huge bruise on the back of my leg from the floorboard being pushed up into me. I wasn't hurt other than some scrapes and bruises, and probably got hit 10-15 times in a matter of seconds before the driveshaft caught the track and ripped itself out of the car. It completely destroyed the (not a nice word)(not a nice word)(not a nice word)(not a nice word)pit and floor board, ripped the hoop out, tore up the x bracing pretty good, broke the LR bell on the rearend, and knocked the rearend fill can off of the deck. I was lucky that this was a lightweight shaft and came apart quickly, but the cost of a Carbon Fiber shaft would have been much cheaper than everything else that had to be fixed.

2 Morals:
They don't run pullbars in 4-bar late models anymore for a reason.
And make sure your loop is in the right place. Take into consideration any movement due to something breaking and pulling back on the driveshaft.