ACPT Carbon Fiber Driveshaft GP, This thing's a GO!!!! Options

[johns68]

I just hung up with the tech guys at ACPT. The info you seek is this.

The 3" version (3 1/4") broke the yoke ears off at 2500 ft lbs of actual applied torque (in a test fixture), they've never been able to break the actual shaft, the U-joint or yokes break before the carbon tube. It weights about 11 lbs

The 3 3/4 inch version handled 6000 ft lbs applied to the actual driveshaft and something (besides the shaft) broke in that case also. It weights about 13-14 lbs.

He said they set the limits based on the limits of the U-joints that fit these shafts. It's not so much a function of the actual shaft, but the attaching hardware. Meaning, if you're u-joints fit it, and you haven't broken them, you won't break it.

All better?

(IMG:http://www.frrax.com/rrforum/style_emoticons/default/beerchug.gif)

Based on this, I have a question: The main benefit here seems to be the safety involved in a catastrophic failure, but the testing indicates that the u-joints or yoke ears will fail long before the shaft. So in a real world failure, you will not broom the shaft, but break a u-joint or yoke ear and drop the driveline just like with a metal unit. Assuming a driveshaft loop, it seems to me a cf tube rattling around in the tunnel will wreak as much havoc as an aluminum one. Assuming no loop, and a broken front joint, wouldn't you now have a better and stronger lever hitting the asphalt and lifting the car? One with a lot more flex and rebound potential so it is less likely to bend or break and therefore more likely to lift the car?

I'm not a materials science guy , so don't know if the linear force from an impact will effect the cf differently than the torsional force it is (well) designed to resist, but it seems any safety benefits would be non-existent over aluminum or steel.

So how far off base am I?

[trackbird]

As I understand it, CF doesn't take impacts well. Meaning, once it starts banging around, it should come apart instead of just beating things up (like a metallic shaft). It's very strong when loaded in the direction of its intended load, but not in other directions. You can build a part with strength only where you need it.

That should be the difference.

[Blainefab]

Kevin is right - the CF would not survive the first sideways hit on the loop without coming apart. Makes it very important to keep it clear of exhaust clamps, TQ arm, etc.

[johns68]

Make it strong in the right direction, but come apart in the wrong direction. Sounds too good to be true. One of these days I'll grow out of my 80's drag race mentality ... maybe.

If I can recover (financially) from this weekend's trip to Alan's shop quickly enough, I may be in. Sgarnett's February date sounds good to me!!

An earlier post indicated it would come complete with u-joints and trans yoke? Posible to get one with a TKO600 yoke instead of T56?

[Blainefab]

An earlier post indicated it would come complete with u-joints and trans yoke? Posible to get one with a TKO600 yoke instead of T56?

John - Double check the length you need for the TKO600 vs T56 - can't just run down to the ds shop and have these things shortened for $20 like a metal one.

[CJ-TA]

Alright, is anyone ready for this GP?

I just blew my second DS in ~12 months and I'm ready to quit messing around with stock ones. Blew the ears off... front and rear!

I'm in, need it ASAP (IMG:http://www.frrax.com/rrforum/style_emoticons/default/tongue.gif)


Kevin, can we still get the hookup on this?

This post has been edited by CJ-TA: Feb 11 2007, 01:15 PM

[trackbird]

I can call and verify prices (it is a new year) and see what the scoop is.

[AndyJ]

I can call and verify prices (it is a new year) and see what the scoop is.

I am still in

[V6RSR]

I currently own two different ACPT CF driveshafts on two different vehicles of mine- They are both daily drivers and the lightweight driveshafts made a remarkable difference in high speed smoothness AND (not a huge difference- but) a noticible difference in acceleration, and mostly a big noticcible difference in RPM's attained. It upped my shift rpms by about 300-500 rpms in each lower gear because of increased spinup speed and lack of vibration (on both vehicles).

As for any question of durability? One of these is in my daily personal work truck (lowered and built 89 Chev c1500 longbed) which happens to be 6 feet long X 4" dia with 1350 joints (the shaft with the yoke weights 7.8 lbs- the steel one was 28 lbs). This truck puts down a modest 340 hp and has a severely built 700r4 (5 planteries, the works- thump your head on the rear window every time it shifts, as well as a Currie 9" rearend with a Detriot Locker. I have the frame completely weled up on this truck and it can haul 4000lbs in the bed and weekly has an average 3000lb load in it for a delivery(last week was 3670). IPoint of this info is I beat the living crap out of this truck daily. This truck also does 140 mph and has been rumored to touch that weekly also although that can just be construde for legal purposes as an internet boast.

These CF driveshafts are strong and light- and will hold up
(ps- the 6 foot 1350 truck shaft cost me $1200 to have custom made (no shipping- I am local to them) Well worth it though considering I was breaking tailshaft yokes with the old steel unit every 6 months due to bad vibrations at critical speeds -had it rebalanced 3 diffenrent times by different shops and everyone said nothing else they could do- it was just too long and too heavy and was suffereing from critical speed vibration.

Camaro acpt shaft- 4.7 lbs: http://www.cardomain.com/member_pages/show...752_16_full.jpg

Truck ACPT shaft- 7.8 lbs: http://www.cardomain.com/member_pages/show...52_101_full.jpg

One of my broken tailshaft collection from the truck with the "prior custom made 1350 STEEL shaft": http://www.cardomain.com/member_pages/show...52_102_full.jpg

This post has been edited by V6RSR: Feb 11 2007, 05:52 PM

[Stang Killer]

Wow, under 5lbs!!!Damn thats light.

[CJ-TA]

Anyword or any interest from anyone else?

[Shortcutsleeping]

*raises hand*

Interested. Is this for a specific application or can it be full custom?


Costas
cars and such...

[jb442]

Didn't realize it before, but ACPT is just a few cities over from where I'm located. I've always liked the idea of a composite driveshaft with it's light weight, reduced vibration and potential for less damage upon u-joint failures (Do they preclude the need for a driveshaft loop? I would guess not, but I'd definitely not worry about it as much with a composite unit.) Anyway, I am interested in this GP if it does go through. So +1

[trackbird]

*raises hand*

Interested. Is this for a specific application or can it be full custom?


Costas
cars and such...

I'd have to verify, but I think it's going to be F-body (stock replacement, or heavy duty stock replacement) only. I'll try to call them this week sometime and get an update on prices and if we can do a custom on this order.

[Stang Killer]

Put me down as a maybe. I know its other stuff I should be buying in my situation, but its one of thoes things I know I will regrette if I pass it up.

[CJ-TA]

Any other interest....

Any pricing info TB?

I need to order one ASAP.. I'm using a borrowed DS right now and I'm affraid that the guy is going to want it back before my next event..

This post has been edited by CJ-TA: Feb 19 2007, 06:18 PM

[trackbird]

I got busy and didn't get them called. I'll do it tonight (if they are not closed for the holiday).

[Shortcutsleeping]

SLACKER!!!

(IMG:http://www.frrax.com/rrforum/style_emoticons/default/laugh.gif) (IMG:http://www.frrax.com/rrforum/style_emoticons/default/laugh.gif)


thanks!

Costas
cars and such...

[trackbird]

SLACKER!!!

(IMG:http://www.frrax.com/rrforum/style_emoticons/default/laugh.gif) (IMG:http://www.frrax.com/rrforum/style_emoticons/default/laugh.gif)


thanks!

Costas
cars and such...

(IMG:http://www.frrax.com/rrforum/style_emoticons/default/ph34r.gif)

I guess I'll send you that image tonight as well.

I knew I was forgetting something...... (IMG:http://www.frrax.com/rrforum/style_emoticons/default/unsure.gif)

[trackbird]

Just hung up the phone with ACPT. I missed my contact by a couple minutes. I left him a voicemail with my number, my questions and a mention that I'd try to call him tomorrow evening if I hadn't heard from him before then.

To be continued.....