Does it give you more rwhp (5%) as they claim??

LMK

I have a 1le (non aluminum).

 

TTT

 

no one gets a carbon fiber driveshaft for weight reduction (ACPT is CF guys right?)

thats $800 better spent on real mods

 

Mmmm don't think so. Here's a dyno, of the same thing you've got - http://ws6.com/mod-10.htm and it looks like a couple HP.

By the way, the 1LE DS is aluminum, and already gets you back a HP or two from stock.

Dave

 

i think that $800 in weight reduction would be better spent on like a $300 fiberglass hood and K members or something. A lot to lose there- and its great to lose weight off the front end.

 

Not just mass, but rotating mass. less rotating mass = more useable hp

 

yea, but i think its like a 3:1 ratio. 1 lb of rotating mass = 3 lbs of normal mass.

 

You're talking a couple HP here... it is NOT worth $800.

I had an ACPT CF extra heavy duty (3.89" diameter) DS, and the d@mn thing broke when the car was being driven less than 1 mile at minimum power between the shop that installed the motor and the shop that was going to install the SLP hood. The front yoke seperated from the CF tube. ACPT said it was all my fault, that obviously I had installed too long a DS. With the assistance of T. Byrne (where I bought it) I managed to prove the shaft was exactly the correct length (identical to the 3" Mark Williams chrome moly shaft I installed in place of the POS ACPT shaft). After MONTHS of arguing with ACPT, they agreed to give me my money back, but refused to pay the shipping or the labor for R&R on the defective shaft.

If ACPT has been honest and fair, I might have considered a replacement, but after seeing how totally dihonest they were in dealing with me, I swore I would never even consider one of their products. I would suggest you look elsewhere if you feel that a CF DS is in some way worth it. I know Mark Williams makes a VERY good CF shaft. But to me, it is definitely not worth it. And the huge diameter makes it difficult to fit everything under the car....

 

I would just keep the 1LE driveshaft. It is a very strong driveshaft. If you are worried about twisting the driveshaft then invest in a loop. As stated above spend the 800.00 on real mods that will make a difference.

 

i have one mainly because the stocker had survived tons of 1.4 60fts, and I think i was pushing my luck, and a AL unit would break just looking at it.

*shrug*

hopefully this one doesn't break.

 

I got a used one in good shape for $400. That's only $100 more than an aftermarket aluminum one. Will it hold up? I don't know, since it's the proper length for a Moster 1350 Yoke 12 bolt, which I don't have. Yet. Point being, I can easily see dropping an extra buck on a used one, but 800 new is insane unless you're pushing an insane car and need every ounce saved.

 

Don't bother trying to save weight or rotational masses on a driveshaft. For a driveshaft you should be looking at strength. A 1LE driveshaft weighs about 10 lbs and my Spohn steel driveshaft with 1350 yoke and u joints weighs 19. (both weighed by me) Much stronger, but only 9 lbs more. The back seat rest weighs 14 lbs, so no big deal! As for rotating masses, the driveshaft is only 3" in diameter, so it's not saving much there. To really reduce rotating masses, look at the heavy, large diameter spinning parts such as the wheels, tires, and flywheels!

 

I am in the fence of what pump gas can hold in total power... I am over 600s now and I would like just a few more.. if the claim was right and 5% to the wheels could mean, being conservative 20more rwhp without more engine power... This is not a track car, I hate the track... I have Al Flywheel and stock rear end... That was my concern.. Anyone had power increase like this?

 

You are NOT going to save 20HP on a lighter weight driveshaft.... several people have explained that.

Power loss in the DS is NOT proportional to power levels.... it is rigidly defined by the energy required to accelerate the mass of the DS (and considering the radius at which the mass is effectively centered) from rest to max RPM. It is one of the FIXED components of driveline loss.... it does not vary with power transmitted. The FIXED rotational losses are IN TOTAL less than 20HP.... and that includes the clutch, tranny, DS, rearend components, axles and wheels/tires. I have verified that with comparison of engine and chassis dyno pulls on my car. Go to WS6.com and look at his "coastdown" dyno test. He is losing less than 20HP for the entire drivetrain.

Also look at the WS6.com comparison of the stock DS to an aluminum one.... nowhere near 20HP.

One more time... you will not gain 5% = 20HP with a CF driveshaft.