i dont think theyre worth the money on a daily driven car, maybe if you go to the track. the problem with our driveshafts are that theyre two piece, so you lose even more hp through the u joint. braille makes a 1 piece cf driveshaft, thats sells for around $1500 iirc. I eventually wanna get that when i am at the drag strip and especially road course more often

 

wow 1500 bucks...I wonder if you have other lightweight stuff if you shouldn't have a lightweight driveshaft...kinda like having a lightweight flywheel and lightweight pulleys can mess with your engine?

 

The driveshaft won't have enough effect to cause any engine problems. I'd like to have a one piece driveshaft. Anyone know why we have the two piece type? Maybe for ground clearance?

 

Are they any weaker? I mean, I know it's supposed to have a higher strength to weight ratio, but as far as where all the cars power is going, and into a small rotating rod, does carbon work that good? Ever heard of them failing?

 

Carbon fiber when laid correctly has an amazing amount of torsional resistance. They don't fail that often. I've never actually heard of it happening. If they do fail however it just turns into a big ass carbon brush vs. the pole vaulting effect when a joint fails on an aluminum driveshaft.

cheers

poorman

 

Cool, thanks for the info! You rock.

Also, bump for the question about why we have 2 piece driveshafts. I'm curious. And we can even replace it with a 1 piece? Seems like it would be much stronger.

 

http://www.sojdm.com/store/pc/viewPrd.asp?idcategory=0&idproduct=90

 

^That's cheap! I might buy it.

 

Haha, cheap. That costs more than my car is worth, lol. Good to see they actually make them for our cars

 

ACPT Carbon Fiber Driveshaft. Replace the OEM 31 lb. driveshaft with the 13.5 lb. bolt on ACPT Carbon Fiber Driveshaft.

mg:

 

ACPT Carbon Fiber Driveshaft. Replace the OEM 31 lb. driveshaft with the 13.5 lb. bolt on ACPT Carbon Fiber Driveshaft.

mg:

how much could it really free up tho? I mean a 28lbs flywheel vs an 8 lbs one only makes a little difference

 

i pondered this awhile ago...not for performance reasons though, but for fuel economy. less un sprung weight = better mpg

 

...and in like ten years it'll have paid for itself. haha. Might be a good justification to tell my girly though...hmm...

 

i pondered this awhile ago...not for performance reasons though, but for fuel economy. less un sprung weight = better mpg

I think you mean rotating weight? Because you're drifshaft doesn't qualify as unsprung weight.

 

whats the difference?

 

yea, theyre designed more for allowing the engine to rev easier and quicker due to last rotating mass. as for the one piece design it frees up horsepower since you dont have the middle u joint soaking up power.

 

the only thing I can think of for using a 2 piece is shock absorbsion. cause the rear diff is a solid mount so it doesnt drop like a trucks.

 

if i wanted a smooth ride id buy a caddy...

 

:rotflmao: I agree

 

So has anybody actually done this. It seems like a really good mod; less mass in the drive train should equate to lower power loss from the drive train, wouldn't this give you a nice boost to AWHP?

Does anybody have any dyno comparisons with the CF shaft? Or, does anyone have anecdotal experience they can speak from, I'd love to hear how it affects 1/4 miles / 0-60 times.

 

i'm really tempted to buy this too... I wonder what HP its rated to support...It'd suck to put this in, turbo your car and have it come apart because theres too much HP...1000 bucks down the crapper haha.

 

I'm curious of the last few questions too!

 

rotating mass has to do with drivetrain. the more rotating mass then the larger loss of hp through the drivetrain. unsprung weight has to do with your suspension.

I'm gonna be looking into getting the braille cf driveshaft prob in spring. If i end up doin it ill make sure to get dynos before/after as well as 1/4.

 

...ill make sure to get dynos before/after as well as 1/4.

I don't think it would affect dyno results as the drivetrain components will already be moving, and this would make any improvement negligible. You should notice an improvement in your 60ft times, though, since you start from a dig and can really tell if the product helped the car rev up easier than before.

 

has no one seen an aluminum one for our cars?

 

whats the difference?

It was already stated above, but I'll elaborate.

Rotational mass is mass that your engine has to start spinning when you accelerate. This means the extra mass means extra inertia in the drivetrain, which equates to more drivetrain loss and slower acceleration. Unsprung weight is anything that follows the road directly, meaning isn't riding on your suspension. The more of this, the harder your suspension has to work, which leads to a rougher ride and worse handling over bumps.

Unsprung weight: Wheels/Tires, control arms, lower shock parts, knuckls and a few other things

Rotational mass: Wheels/Tires, axles, driveshaft, flywheel, pullies, and lots of other little things in between and in the engine.

 

http://www.ultrarev.com/product.php?productid=45550


Couldnt get there site directly but its only $404. Yes it is alloy and carbon would be better if it breaks because it would just shatter. However alloy is much cheaper.

 

http://www.ultrarev.com/product.php?productid=45550


Couldnt get there site directly but its only $404. Yes it is alloy and carbon would be better if it breaks because it would just shatter. However alloy is much cheaper.

This one is also lighter than the CF one. It is 12.6lb compared to the CF 13.5

 

i def think im gonna buy the aluminum driveshaft shop driveshaft. good find!

what i find odd, is i called them a while ago about cv shafts for my car and they said they arnt available... hmmm

 

light weight cv shafts? or your sayign cv shafts in general. to my knowledge other then new ones from the dealler all others are reman units any more.

 

the alum one says rated for 750hp... more than ill ever have. If I can get people to buy my old stuff ill be able to buy this and let you all know how i feel about it. otherwise it wont be till spring.

 

You also cant go by just weight. Do you have the diameter of both DS? If the alloy is bigger any weight loss is detracked by the fact that it is farther out from the center. Which I would think it is because I didnt see any of the CF shafts needing to have anything pounded on for clearance or clearance being tight.


Bang for buck goes to alloy for sure. Didnt know they where so cheap. Might get one if they come down alittle more.

 

this will free up rotating weight and being the tube will torsionally twist more (steel twists about 5 degrees and the aluminum twists about 20 degrees)

Can someone explain what they are saying, because it doesn't make sense when they phrase it this way. I am interpreting it to mean that the side away from the engine on the steel driveshaft will be 5 degrees "behind" the side closer to the engine, due to torque, while the aluminum one will have a 20 degree difference between the two sides. How is this better? Doesn't that mean that the aluminum driveshaft is torsionally weaker than the steel one?

 

This doesnt mean the shaft is WEAKER...it simply means it is more flexible. Imagine it like a spring. There are springs rated to hold huge loads with both high and low deformation factors. So you can have a springy srping or a stiff spring that both hold the same amount. Hope that makes sense...

Now, imagine if at rest there were two vertical lines painted on the face of each shaft end. What they are stating is that under rated load, there will be a 20 degree difference between these lines as compared to the 5 degree on an alloy shaft. Again, this doesnt mean the shaft is weaker, its just more flexible.