Driveshaft has me worried

[Sal Lubrano]

Do you think I am pushing the drivesahaft to its max. I have a loop but there is too much talk of people snaping thier stock drive shaft and taking out thier transmissions, floorboards, exhaust, ect.... With my mods should I be worried??

 

[1fastgn86]

Do u have a transbrake? What are your times in the 1/4?

 

[Sal Lubrano]

no trans brake. Actually never had the car to the track but will be going soon.

 

[GNTIM]

From what I have read/ heard/ seen I think you are o/k as long as the u-joints are good, replace them with h/d units if they are original. The trans brake is the big factor or high hp motor, but you never know. I have a Dynotech shaft with loop and Moser axles but I rarely go to the track. Just paranoid I guess.

 

[RUQWKNF]

I agree with what GNTIM just said with this to add.
In all the years I've been racing Turbo Buicks and had friends race these cars, the stock driveshafts with upgraded u-joints will live on foot braked cars that are running in the mid 10's or 60ftin in the mid to high 1.50s. Even the stock wheel studs will live, eventho it is recommended to change them to larger, and required at NHRA and IHRA legal tracks once you get into the 11.50 range. It's once you start getting your 60fts lower than mid 1.50s or you throw in a trans brake that they tend to do south. When I was running a trans brake on my Turbo 400 in the grey car, I was running a Dennys drive shaft that they warrantied not to break and would replace for free if I ever did. Now, don't know how good that warranty really is cause anything can happen but we did alot of homework before deciding on Dennys.
HTH

Patrick

 

[WLDWST]

I see our combos are very similar ( GT67P, 60's FMIC etc ). I am more of a proactive person than a reactive one. I am installing an Eaton posi, 30 spline axles ( with c-clips eliminator kit ), and 1/2 studs. Also a custom driveshaft with the upgraded u-joints. I hate not having confidence in my parts. I have never regretted overbuilding, and it may save a bundle in the end. If you are concerned enough to post this thread, beef it up a little and have some piece of mind. The stock stuff was never designed to take the mods you and I have. I don't want to debate the strength of the stock components with anyone. I am sure they will take alot, I am just not convinced that it's worth the risk at this horsepower level. Regardless of the sixty foot. The torque of these engines can do damage over time.

 

[Alky V6]

I see our combos are very similar ( GT67P, 60's FMIC etc ). I am more of a proactive person than a reactive one. I am installing an Eaton posi, 30 spline axles ( with c-clips eliminator kit ), and 1/2 studs. Also a custom driveshaft with the upgraded u-joints. I hate not having confidence in my parts. I have never regretted overbuilding, and it may save a bundle in the end. If you are concerned enough to post this thread, beef it up a little and have some piece of mind. The stock stuff was never designed to take the mods you and I have. I don't want to debate the strength of the stock components with anyone. I am sure they will take alot, I am just not convinced that it's worth the risk at this horsepower level. Regardless of the sixty foot. The torque of these engines can do damage over time.

I whole heartedly agree. You're a smart thinker.

 

[chopped39]

I was looking at strange catalog i didn,t know they sold drive shafts. chrome-moly. they offer ends also. the shafts with out trans yoke are 339.00. is this any good for price. I called suburban drive line in ill and they told me 350.00 and said it was good to 900 hp. that was with 1350 u-joints and .090 steel tube. strange does not say what level of power it will take. but if a good drive shaft is under 400.00 it well worth it. cheap insurance from over revving your motor or any other damage that will occur during the breaking process just my 2 cents:biggrin:

 

[Alky V6]

Make sure you get the Mark Williams billet front yoke also.

 

[tom h]

is the stock rear yoke considered "strong enough" , once the drive shaft and front yoke have been upgraded ??

 

[chopped39]

I would update to 1350 joint with yoke. cheap insurance

 

[Alky V6]

I've never seen a problem with the rear yoke. Maybe others have identified a problem.

 

[V6POWER]

Where do you buy a Mark Williams yoke?

 

[YouLikeThat]

I'm going to get an aluminum drive shaft from dynotech they rate it at 1000 HP and it runs $369. They also sell crome moly shafts for 379 that are rated at 1500 HP.
I havn't done business with them yet but they seem very helpful on the phone.
FYI, they told me the stock yoke would break before their aluminum shaft would.
Dynotech Driveshaft Custom Driveshafts, High Speed Balanced built to your specifications in Steel, Aluminum and Composite Materials
Good Luck,
Scott

 

[V6POWER]

Thanks for the link.

 

[Turbo1dr]

After twisting 2 driveshafts in two and twisting the yoke on an aluminum shaft I upgraded to a carbon fiber shaft with 1350 joints and yokes on both ends. Light weight and strong.

 

[YouLikeThat]

After twisting 2 driveshafts in two and twisting the yoke on an aluminum shaft I upgraded to a carbon fiber shaft with 1350 joints and yokes on both ends. Light weight and strong.

What did the carbon fiber shaft run and how much HP is it rated for and where did you get it?
Thanks,
Scott

 

[Alky V6]

Carbon fiber baby! That is the ticket. If it does go bad, I hear it just shreds and doesn't do nearly as much body work damage as a steel. That will be my next shaft for sure.

 

[Turbo1dr]

What did the carbon fiber shaft run and how much HP is it rated for and where did you get it?
Thanks,
Scott

$1000 It's not cheap. I figured buying exhaust systems and floorboards were just as expensive too. This is the shaft I bought...

Taken directly from their site....


Precision Shaft Technologies, Critical Link™ Driveshafts

Carbon Fiber Driveshafts

The finest driveshaft available anywhere. Each driveshaft is specifically designed by our Engineering Department to optimize the characteristics of Carbon Fiber required in your special application. Passed SFI test at 2800 Ft/lbs torque. Prices range from $500.00 to $950.00.

"Our newest "Critical Link" Carbon Fiber Driveshaft for Drag Racing application is 3 3/4" diameter, a 50" driveshaft weighs only 6LBS - with 1350 series solid U-Joints add 3LBS and Slip Yoke add approx 2 1/2LBS."

Advantages of Carbon Fiber

Lighter than steel or aluminum.
Three times torsional strength of steel.
Torsional spring rate allows better tire hook-up.
Torsional spring rate allows smoother shifting.
Less shock load to the differential.
Eliminates or dampens high speed vibrations.
Reduces transmission and differential breakage.
Characteristics can be varied by changing the wind, angles or diameter. PST offers both steel and 7075 Billet Aluminum yokes.
In drag racing applications - a better 60 Ft. time.
ET's have been lowered in some cases by as much as .120.
In stock car racing better control out of corners is the result of the torsional spring rate.
In road racing smoother shifting and better durability of transmission and differential have been reported.
Tested on Cobra's at 180 MPH on Dyno with no vibrations.
A much greater safety factor - carbon fiber will return to a fiber and not create shrapnel under the car, as would aluminum or steel shafts.

 

[Alky V6]

Don't forget the highest critical speed/length and diameter limit of any shaft available. Overall, a safer driveshaft that helps put more power to the ground. Man, I should have layed out the bucks for one instead of my 3.5" steel.

Just don't put a knick on a carbon fiber shaft though.