[1day]

I just talked with James at ACPT about the 2008 STi Carbon driveshaft and this is where they are at for us:

We are about 90% done with our R&D of the 08 STI driveshaft. The other years will not work since the 08 is a couple inches longer than the previous years. By the end of next week we should have everything completed for the
08 and we will start taking orders and start building shafts for the 08 STI.
If you have further questions, feel free to contact me.
James Martin
ACPT Inc.

Can't wait

[caveguru]

creepy- I just had almost the same conversation with him. The wait is killing me...

[EtoS]

What do the current stock ones have and what are the specs on it? What's the specs on this ACPT one and cost? I don't remember exactly what the older STi carbon driveshafts cost but I think it was 1-2k? Either way the stock one better be a god awefull pig to make getting a carbon driveshaft worth it.

[Digitalfiend]

I believe the ACPT CF driveshaft was $900-ish for the previous gen, so I expect an initial premium on the '08 (even if only because it is a couple inches more material).

As for performance, less rotating mass is always a good thing and the driveshaft is no exception. While it's not going to be like going to stage 2, the benefits are definitely there. Just do a search and read the reviews from previous model owners.

[sutter2k]

^^ also see many people have vibration issues.
Would like to know that will not occur.

[TheLastSTI]

Originally Posted by Digitalfiend

I believe the ACPT CF driveshaft was $900-ish for the previous gen, so I expect an initial premium on the '08 (even if only because it is a couple inches more material).

As for performance, less rotating mass is always a good thing and the driveshaft is no exception. While it's not going to be like going to stage 2, the benefits are definitely there. Just do a search and read the reviews from previous model owners.

A couple things I wanted to clear up, the d/s is about 1100-1200 retail (maybe less on g/b's) for the "previous gen," next, another person commented on vibration, I've never felt a thing, the driveshaft fit like a glove and has only performed like expected.

I'm sure James will get everything squared away with the 08's, they're a great sponsor of mine. Great people with a great product!!

-Chris

[caveguru]

Originally Posted by EtoS

What do the current stock ones have and what are the specs on it? What's the specs on this ACPT one and cost? I don't remember exactly what the older STi carbon driveshafts cost but I think it was 1-2k? Either way the stock one better be a god awefull pig to make getting a carbon driveshaft worth it.

I believe the stock one on a GD STI weighs around 25.5 lbs, so I would guess ours weigh ~26. The prototype that James has out for testing weighs under 14 pounds, so you're looking at around 12 pounds removed. That's like doing a triple-crank pulley mod , or a <10 lb race flywheel. But it goes further than that- read the threads on here and nasioc where people just love these things for the change in acceleration (0-60 times reduced by 0.4 s!), the additional low-end grunt, the smoother shifting, and to some, less NVH.

Some people describe the car's handling as feeling "lighter" as well, which might be the result of the reduced inertial moment. I'm not sure how large the effect is relative to the sti's weight, but remember the trick where you spin a bicycle wheel while holding it by the two ends of the axle, and then try to tip it sideways? The inertia from the wheel spinning tends to resist that. Since the driveshaft is in line with the direction the car is going, the inertia of the DS spinning would tend to resist the car's turn. Considering that in 5th and 6th gears the shaft is actually spinning faster than the engine, I would at least believe that the difference in inertia could be felt.

Frank

[VSGTS14]

gotta get a group buy together for it!

[tshrey]

I'm in for that the day they become available...

[1day]

Originally Posted by VSGTS14

gotta get a group buy together for it!

Count me in.

[MEXSTIMPREZA]

Me too!

[GilMikalian]

Okay, so I did some searchin' and I saw reports of gains of .4 sec's for 0-60 times and read numerous posts liken the bump in power as "another stage 2." Is this for real? Can we really expect this type of improvement? Seems for a grand, you're getting a lot of bang for the buck. This plus reported increases, significant increases of 5+ mpgs, seem like this is a mod I did not count on doing, but will do at some point.

Looking forward to getting some feedback on the 08s.

[darrenbt]

Here is a link with a number of reviews. Might answer some people's questions...

ACPT Carbon Fiber Driveshaft, Thread #2

After reading that it looks like Stage-2 w/ Driveshaft might be the new target...

[1day]

^ exactly. And you don't even need a tune!!

[MEXSTIMPREZA]

How safe and durable do you guys think this driveshalft is, especially at high speeds? I do not want to bash (or spend two hours reading posts from a different car), I really like this mod, but a broken shaft from the front at 120 mph...