Aluminum drive shaft

[mjhockey155]

I cant seem to find any information that i was looking for on these. My situation is that i have a stock 240sx coupe se w/o ABS with a bad drive shaft. I want to replace it with a 1 peice aluminum drive shaft. My concern is that the 1 peice for the KA will not fit for my future SR swap.

[Signum Temporis]

it should fit... if u can run a stock driveshaft with the sr, then why not a new one? ur all good buddy :D

[levelgx]

yea, it fits on my SR fine

[shade]

Interchangeable. Get one from DSS or just get one thats balanced.

[Matej]

It fits.

Speaking of one-piece aluminum driveshafts, did you guys who run them notice a difference after installing it, did the motor feel more responsive?
I'm thinking about picking one up.

[clark]

projectRDM (formerly r240na) seems to be the most informed about things like this (driveshaft fitment issues/interchangeability). i suggest you PM him, maybe he will be nice enough to share the information with you.

but umm, the way i see it. the aluminum DS's are usuall ~10lbs. the steel one piece driveshafts are usually ~15lbs. the aluminum ones are more expensive than the steel ones. unless you are a D1 drifter or a richboy, there really won't be any need for the aluminum. you prob wouldn't see any noticable gains between a steel one piece and an aluminum 1 piece. i have 15lb steel DS and i noticed quicker revving and smoother drivetrain.

[Signum Temporis]

if u take weight off of ur powertrain ur definitaly 100% positively going to get SOME sort of power gain

[wangan_cruiser]

^^^ thats true. less stress to your motor by taking some of the weight from a rotating mass and heavy ass stock driveshaft

[Matej]

Definitely, I'm just curious if the difference is significant enough to justify spending the money on it.

[jinesz32]

i got 15 lb steel one piece on mine, i notice the difference alot, theres alot more response :D

[devnull]

An aluminum driveshaft will twist more than a steel driveshaft.

Basically a steel driveshaft will break the wheels loose faster than an aluminum one.

[g-via]

lighter driveshaft = smaller moment of inertia

With the smaller inertia, it will be able to spin at the same RPM as the previous one with less power. (therefore same amount of power = faster movement)

The myth about the aluminum driveshaft twisting is only true under certain situations. The shear modulus of the driveshaft (J) won't be a problem under normal acceleration (one direction of rotation)
It is when you are accelerating and braking frequently. The shear modulus is subjected to torsion because of the conflicting inner stresses. On top of that, if you are doing it frequently, the fatigue strength of aluminum is less than that of steel, so it will yield sooner.

Just my .02 from an engineering POV

[Signum Temporis]

An aluminum driveshaft will twist more than a steel driveshaft.

Basically a steel driveshaft will break the wheels loose faster than an aluminum one.
this isnt necesarily true... some aluminum alloys have a higher young's modulus to strength/density ratio than steel...

but on the vice versa, the "twisting" is such a decimal amount that there's no difference between driveshafts in that sence, unless it's made out of some rediculous material like rubber

just my .02 from an engineering standpoint (i basically just said what he did hahahahaha ^^^^)

[g-via]

^wow you picked the wrong thread to post...

Steel : E = 193 GPa

Al alloy : E = 69 GPa

...just think about it (if you know anything about Young's modulus of elasticity or anything about shear stresses....or anything.)

[Fries]

People can't read anymore? On paper it looks like it will make a huge difference, it's practically common sense. He is not looking for the technical aspects of this. He wants to know...

...I'm just curious if the difference is significant enough to justify spending the money on it....


P.s. Matej, I get my new KA for my drift s14 in 2 weeks, 1piece aluminum driveshaft is coming too. I'll let you test it, blah blah etc...

[g-via]

for my previous statement:
it does depend on the type of steel and aluminum used

but anyways, back on topic, sorry OP

[slim]

the ka and sr non abs driveshaft are the same length.
i noticed a small difference in acceleration. not as much as i thought it was going to be.

[Matej]

P.s. Matej, I get my new KA for my drift s14 in 2 weeks, 1piece aluminum driveshaft is coming too. I'll let you test it, blah blah etc...
Sweeet, thanks brororooo. Do you have two S14's now, or is your drift S14 your S14? Haha.

And I guess I will most likely have an aluminum driveshaft custom made, seems to be cheaper than what online stores are selling them for, I was quoted about 300$ by a couple local shops.

[MrChow]

Also if you think about it that way aluminum will absorb vibration more than steel.

To the OP: Here's the link to DSS for 240sx http://www.driveshaftshop.com/240parts.ivnu
As far to what your asking and to my knowledge there the same thing. Since the KA and the SR basically use the same tranny and diff there wouldn't any different in the drivetrain. So yes a the drive shaft your getting will work with your SR swap. I'm 99% sure of that basic on what I know and have seen.

[wangan_cruiser]

why would they sell an aluminum driveshaft that will break soon enough?

[flip3d]

Just get the steel. Its still better than stock and wont break the bank.

[a_ahmed]

What kind of noise increase can one see from either aluminum or steel 1 piece.

I heard the carbon 1 piece has great chance of shattering when hitting bumps on street roads. True or not how does it apply to the alum and steel ones too.

And what's up with the breaking and twisting shiznit :-/

[Signum Temporis]

for my previous statement:
it does depend on the type of steel and aluminum used

but anyways, back on topic, sorry OP

yeah, thanks for reading my post before trying to shoot it down

[g-via]

hey at least i was able to admit my mistake

[Signum Temporis]

true, its all good :D

dont mean to throw the main post off topic,

but do they make carbon fiber driveshafts for 240's?

[projectRDM]

Yes, ACPT makes one for like a grand. KA->SR driveshafts fit the same as long as they're the same chassis, IE S13 won't fit S14 and vice versa.

The aluminum driveshaft adds a noticeable reduction of loaded engine revving, meaning the engine revs easier/quicker just as a flywheel would do, but you're not increasing power at all, you're just freeing up a little of what you already have so it feels like there's more power.