V8 driveshaft torque capacity (not fitment question)

[Gotta_gofast]

So, what are all you guys (with 400+ hp) using for a driveshaft? The factory 2.3L shaft in my '93 longbed held up to a mild 302. I am however concerned with the 331ci stroker and a built hard shifting C4 transmission. Anyone have any input? I'm considering having a custom aluminum shaft built, but I've never dealed with a driveshaft shop before so any recommendations would be welcome.

So, what driveshaft are you guys running and how much power is being put to it?

 

[wahlstrom1]

Well, guys using 4wd low are putting more then twice the torque a 2wd would be through their shafts without issue, especially those with an 4wd/v8 combo.

But, I've broke mine after belly dropping the truck on it so I had one built. The stock ranger 1 piece driveshaft is .065 wall tubing, and I had my parts shaft (lengthened from an explorer) retubed with .090 wall, and haven't had an issue yet. I'd think a higher quality U joint would be a better expenditure/failsafe then a custom built shaft.


*** Increasing diameter will also increase strength significantly.

 

[baddad457]

I ran the stock 2 pc shaft in mine for several years behind a manual transmission. Wasn't til the 331 came and I subjected it to a dry burnout on rough pavement that the middle cast yoke broke. That was the only part that broke too. I replaced it with a shortened (by 2") shaft from a 93 E150. Only drawback to it is it bumps the floor of my 89 Supercab when the truck has 2 people in it.

 

[847b]

Definitely upgrade the u-joints...

I will measure my steel drive shaft when I get a chance. Whatever mine is, it has stood up to 4 seasons of drag racing with a transbrake, 3500 stall converter and 350 hp to the wheels.

 

[Gotta_gofast]

Well the stock 2.3L longbed shaft I have is right around 4 inches in diameter (this is from a poorly calibrated eyeball). I remember first doing the swap thinking "this driveshaft is a little overkill for a 2.3L". I've already got top quality joints in it from when I put the first 302 in. I think I'll just run a driveshaft safety loop for added security against potential body damage. Then again, I might eventually have a custom shaft made because I've been tossing the idea of a centrifugal supercharger once I get the 331's issues straight.

Thanks for the input!

847b- what have you found to be a weak spot in the frame? I noticed with the 302 the chassis would flex by the bed a lot. I'm thinking some cross bracing and ladder bars.

 

[Mac]

Hope you're taking a lot of pictures to tease us with.! Would sure think that shaft would do. You've upgraded the joints and going to run a C-4, it's normally the shock load that takes the joints out. Don't see a problem even going with that charger.
Dave - Up Nord

 

[Gotta_gofast]

Hope you're taking a lot of pictures to tease us with.! Would sure think that shaft would do. You've upgraded the joints and going to run a C-4, it's normally the shock load that takes the joints out. Don't see a problem even going with that charger.
Dave - Up Nord

Easy big fella, no boost yet. I'll try to take some pictures. As a matter of fact, I'm going to be cutting up some long tube "in frame" headers to fit the ranger chassis (not a big fan of shorties and not going to pay $+400 for long tubes). Maybe I'll snap some pictures of that to satisfy your craving. Wait til spring when its warmer. I'll make more progess then.

 

[baddad457]

Well the stock 2.3L longbed shaft I have is right around 4 inches in diameter (this is from a poorly calibrated eyeball). I remember first doing the swap thinking "this driveshaft is a little overkill for a 2.3L". I've already got top quality joints in it from when I put the first 302 in. I think I'll just run a driveshaft safety loop for added security against potential body damage. Then again, I might eventually have a custom shaft made because I've been tossing the idea of a centrifugal supercharger once I get the 331's issues straight.

Thanks for the input!

847b- what have you found to be a weak spot in the frame? I noticed with the 302 the chassis would flex by the bed a lot. I'm thinking some cross bracing and ladder bars.

If the stock shaft is that big, then leave it be. It'll do.

 

[wahlstrom1]

My 98+ stock replacement was 3.5" dia, the one I replaced it with (same dia. as original 2 piece) is 2.75" dia.

 

[847b]

My drive shaft (1 piece) is 3" OD steel tube. Not sure on the wall thickness and I can't find the receipt.

Originally Posted by Gotta_gofast
847b- what have you found to be a weak spot in the frame? I noticed with the 302 the chassis would flex by the bed a lot. I'm thinking some cross bracing and ladder bars.

I have not found the weak spot yet. I have a four link rear suspension and to mount the front brackets I made a heavy duty cross member out of 2" x 6" x .188" steel tubing and 1/4" plate. In addition, I also added a cross member behind the rear axle to mount shocks to. These two items really stiffened up the back. While under construction I did notice (as you mention) how flexible the back half of the frame is. I think cross bracing would be a safe bet and get the truck to hook better. Hope this helps!

 

[Mac]

Don't get me wrong but you have a nice rear end! Some guys just cut and hack and make something fit, a lot of you guys take some pride in your work and it shows. --------------- Brain working. Seem to remember a narrowed 9" 31 spline sitting in the gargage. Came out of all things a Pinto.
Dave

 

[Iron Ranger]

I believe mine is either a 3 1/2" or a 3 3/4" one piece driveshaft I had custom made by a local driveline shop for $185. It's much better than the wimpy 2-piece(which I think was 2 3/4" dia.) Even spritzed for the Spicer joints.

This is definitly one area you don't want to cheap out on. I didn't have a lot of money at the time, but I knew that it would be well worth it.

 

[originalnitro]

I twisted a stock 1 piece into at the rear joint wth 462 rwhp. I would go custom when/if you supercharge it.

 

[doorgunner]

Get some .250 wall high-carbon seamless pipe.....then go to the Jon Deere store & pick up a couple 7" (cap to cap) u- joints.....give the U-Joint shop 400 $ and the dimensions.....problem solved 4-ever.....

now.....about the weak tranny & differential !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

 

[baddad457]

Get some .250 wall high-carbon seamless pipe.....then go to the Jon Deere store & pick up a couple 7" (cap to cap) u- joints.....give the U-Joint shop 400 $ and the dimensions.....problem solved 4-ever.....

now.....about the weak tranny & differential !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Are you off your meds again ?