Drag racing/Sled pulling drive shafts!!!!

[jktcummins]

Ok lets talk drive shafts. There is not decent info that i can find as to what works and what doesnt. On a ex cab long box truck you have around 70" from the yoke on the transmission to the yoke on the diff. From what I have gathered you cant get away with running a one piece shaft for drag racing being that long. But some people say its fine. I have heard of using 4" 1.34 and 1.80 tubing on the big one pieces shafts. And i have heard of people using 4" .093 in a two piece.

Is there any way we can get a list going of what others are using or have tried and how they are working either sled pulling or drag racing.

[Supershafts]

You can run a 1 pc shaft, i have been building 1 pc shafts longer then the big 3 have been using them, 70" is nothing nowadays with the new AL and CF material shafts available today . I have trucks up to 90"

The issues are these.....

Weight, hp, 1st gear, and your max rpm....

The length and diameter are dictated by the rpm and hp in 1st gear.

In the diesel world the hp figure can be a issue since 700 hp can lead to 1500 ft lbs, having a 3.55 1st gear can make the shaft see 5300+ ft lbs

So using your 70" shaft in 4" AL we have a rpm limit of 5600, and torque issue at 6500...

There are your answers.... now if you start bouncing the suspension...you'll have big issues...


In the drag racing world if you use a stl shaft in .134 or .180 wall you are just beating yourself...


For every pound in the driveline you can x that by 10 pounds of carrying weight....
So if you want to go fast, and run a 100 lb shaft over a 20 lb shaft.... the 20 lb shaft is = to carrying 200 lbs... the 100 lb shaft is = to carrying 1000 lbs....
So what happens to your truck when you lose 800 lbs of carrying weight...

[jpowel29]

Great info.

I am drag racing a 2wd RCLB DMax and have been wondering how to get rid of the stock 2pc steel shaft and carrier bearing.

Is there a number to call to get one started?