Custom Aluminum Driveshaft

[SonySC]

I just picked up my NEW custom aluminum driveshaft that Driveline Services of Concord made up for me. $300 out the door with new super duty U joints and flange and yoke. One heck of a deal. I have all the info if anyone wants one made...

George Clarke aka the SonySC@hotmail.com 925-984-3785 cell

[rivlee]

I'll e:mail you.

Lee

[plev72]

I'm sure this has been covered... but what kind of weight is recovered by going with the aluminum? Is there also an increase in durability? I'm assuming lighter drive shaft = less parasitic loss due to rotational mass? Also assuming that it would multiply the advantages of an aluminum flywheel?

[Aaron Pedroza]

It may be off a little but I have heard as much as .1 for every 10 lbs off of rotating mass.

[Coast to Coast SC]

The power increse of removing rotating mass is a function of two things...1.The amount of weight removed 2.The reduced weight's distance from the point of rotation (centerline of the output shaft of the tranny to center of pinion on rear in this case). While no driveshaft material is far away from this point, the run of the shaft is considerable and therefore significant weight could be lost. I believe that greater gains could be had from a lightened flywheel as the mass removed and the distance from point of rotation (center line of crank) to point of removal is greater. However, the driveshaft would certainly compliment any other lightening. Any significant driveline lightening for $300 is great. What is the actual weight loss? It is balanced right?

Anthony

I'm tired, can I go back to sleep?

[mannysc]

having had ywo alluminum driveshafts on my explorer Id say watch out for debree on road , the first one became history


after a crocodile hit it it made a small ding in it then it wobbled and tore out within ten miles.

the second i messed up working on rear end I dinged it didnt look bad maybe 1/8 deep and 1/2 inch id it ran good then one day week later it bended and tore out taking exh with it .

dont know if stock are like after market but the stock alluminum shafts suck.

ive installed a steel one and have no problems and notice no hp loss.

the alluminum flywheels now thats a noticable change.
so good luck and keep us informed on its performance.

ive just had a bad taste of aluminum maybe its just my bad luck.

[Aaron Pedroza]

Even though there can be significant weight reduction with a aluminum flywheel I wouldn't do it with our beasts. The rotating mass of the flywheel helps a ton to get our cars moving. I know when I had a 10" converter compared to the 11" I have now the short time went from a 1.86 with stock down to a 1.98. Even though it was less weight and higher stall the car just didn't want to get going. You would have thought it would have made it up on the back end but I actually lost 2 mph on the top too. The stall was the same with my new 11" too.

[mannysc]

good point .
maybe I should put my stock flywheel back on .
I noticed I have to rev more to get going on my 5 spd .
and burnouts got shorter. also second gear used to fry tires about 20 feet now only about ten feet it lost torque.
I just thought it was the summer heat. car dont seem as torquey.

[Rob Noth]

The main advantage of an aluminum driveshaft is the higher RPM capability, or critical speed. It becomes important if you like to go fast, and especially if you have changed to a shorter rear gears (3.55's, 3.73's etc).

There really isn't as much of a weight advantage with an aluminum driveshaft vs. steel, because it's rotating. The moment of inertia is (mass x radius^2)/2. Aluminum driveshafts are lighter but larger in radius. The MOI decreases linearly with the mass but increases with the square of the radius, so the difference between the steel and aluminum shafts is not as much as you would expect.

Manny - sounds like you did have some bad luck there. BTW stock aluminum shafts are nothing like aftermarket ones, not even close in terms of strength and quality. But that doesn't matter if it gets dinged, it's gonna break anyway...

[rivlee]

It sounds like the gains are small and the downside nasty. :eek:

Lee

[al35thsc]

Originally posted by mannysc
after a crocodile hit it it made a small ding in it then it wobbled and tore out within ten miles.

Not that I'm saying this didnt happen (honestly, I'm not, I dont care what u bastards think of me the way I've been with Manny, it's NOT what I'm saying) I'm curious to know where u were driving that you hit a croc?

On a side note, anyone know a good carbon fiber guy???

Alex

[mannysc]

by crocodile I meant the calif highway type diesel truck tires when they shred their tread they leave those crocodile s on the highway so get off Al,s back you b sturds.lol dont sweat it Al I used a term not used much anymore, sort of a 70,s 80,s term for tire tread

[Rob Noth]

Lee, somehow this did end up sounding pretty bad for aluminum driveshafts, but really it's not that way. It is a safer option if you plan to go fast or have lower (numerically higher) rear gears.

Alex, if you're thinking about a CF shaft, don't waste your money. PST in Florida (where I got my aluminum shaft) made two CF shafts for a couple other guys in SCCOA, and both those shafts broke at the track. Apparently these were like the only CF shafts they've ever made that broke like this. If I remember correctly it was related to the fact that our IRS allows the diff housing to move around in all directions, and combine that with some wheel hop and the CF shafts just break up.

[al35thsc]

:(