[Jelphree]

SoJDM,

PM'd you regarding the shipping labels.

[Kevin]

Originally Posted by OrangeDot3083

I'm sure it’s in one of these posts some where and I've looked for over the past 30min and could not find it.

So on with the question, what is the max whp these things can take? And if and that is a very big IF. If I was to break one, let’s say while launching it at the drag strip would it be replaced under warranty?

When I first got involved with ACPT, James told me that the driveshaft has been used routinely on 700+ hp drag applications. Are you running that kind of power?

Originally Posted by wrrrx

No contact anywhere...
... that I could see.

Unfortunately, when I drove it, there's a lot of vibration thru the shifter. I can' feel any vibration in the car itself, only the shifter. In fact, if I pull the shifter sideways towards me, the vibration/noise goes away. Also under load it seems to lessen.

I have Grp N eng/trans mounts, TiC short shift kit and TiC clunk killer rear "outrigger" bushings...

When coming to a stop, the noise/vibration seems to get worse, or at least be more noticeable.

Can you elaborate more? Can you provide more detail related to shifter vibration? Normally, there is an inherent about of noise/vibration that can be felt in the shifter with the mounts you have installed in your car. If the only vibration or noise you experience is in the shifter, it is likely not going to be an issue but I would like to hear more information.

When did you install your bushings? Did you notice any increase in noise/vibration?

Originally Posted by DCH

Hit up a road course and during 100+mph straights, my seat was vibrating like crazy. I even managed to hit 120+mph and my rear view mirror was just useless...it was so shaky.

Cruising on the highway from 70-80mph, there aren't any vibrations at all.

Do you have any other drivetrain mods? I would suggest following Jim's advice of checking your ACPT driveshaft flange center cast metal area to determine whether there are any signs of contact from the differential pinion nose (the central part). If so, I believe ACPT is willing to replace the shaft.

[bbong]

Drove the car for 200 miles last Saturday, sometimes reaching speeds of 100mph, not even a sound from the DS. Also looked under the car, and no visible scratches besides the one that when I had the protection plate on. Ebrake lines are clear of DS too.

DS has some mean pulls behind it, and 4 wheel smoking launch, holds up pretty well.

Good luck with your DS's guys.

[949]

how many mm or inches is your ds away from the ebrake cables?

[DCH]

Originally Posted by Kevin

Do you have any other drivetrain mods? I would suggest following Jim's advice of checking your ACPT driveshaft flange center cast metal area to determine whether there are any signs of contact from the differential pinion nose (the central part). If so, I believe ACPT is willing to replace the shaft.

I've got the TiC Super Shifter Set, Cusco Motor and Trans Mounts, TiC Klunk Killer, Outrigger Bushings, Tranny Crossmember bushings...pretty much everything from TiC and Kartboy.

Hopefully I can crawl under the car sometime soon and check cables.

[OrangeDot3083]

Originally Posted by Kevin

When I first got involved with ACPT, James told me that the driveshaft has been used routinely on 700+ hp drag applications. Are you running that kind of power?

O god no! However me and a buddy that does have up words of 500+ have been talking that would it be possible for a car at a drag strip with r-compounds on to break one in half. He would get one if he knew that he had a warranty to fall back on, should some thing happen to him like that.

[wrrrx]

Originally Posted by Kevin

Can you elaborate more? Can you provide more detail related to shifter vibration? Normally, there is an inherent about of noise/vibration that can be felt in the shifter with the mounts you have installed in your car. If the only vibration or noise you experience is in the shifter, it is likely not going to be an issue but I would like to hear more information.

When did you install your bushings? Did you notice any increase in noise/vibration?

ALL IS GOOD!!
It was the.. uhhh, whatever the black cable running fwd to the bellhousing is. It was TOTALLY laying on top of the driveshaft -which is why it felt like it came 100% from the front...
I mustered all my mechanical skilz (heh) and utilized the latest in clamping and constraint technology.
(In other words, two zip ties and problem solved!)

NO MORE VIBRATION at any speed really. Well, there's a bit more noise and vibration from the drivetrain itself, but it is NOT from the driveshaft being out-of-balance or anything.
"Tested" to 85mph, (on a closed course, natch ) no bad vibrations, Thank God- and thank ACPT and SoJDM.

WhoooHOOOO!!! (Where is my dancing monkey emoticon??)


PS- Kevin/Nivek, yes, the shifter bushings (installed 18 months ago) resulted in more vibration, as do all/most bushings. But it's all "Good Vibrations"!

[laueddy]

One Issue.

While I Don't have any vibration issues when going on hwy, at any speed. I can here my DS Binding when making greater than 90 degree slow turns..! Not sure about fast turns, as the car is too loud for me to hear it.

Anyone has the same issues?

[RexStage1]

I seem to have a binding sound coming from my right rear during sharp turning as well. Not sure yet either though.

[jermdeez]

Originally Posted by RexStage1

I seem to have a binding sound coming from my right rear during sharp turning as well. Not sure yet either though.

how bad is it? I mean the stock drivetrain/susp binds a fair amm on turns like you described.

[949]

post up pics

[wrrrx]

Originally Posted by laueddy

One Issue.

While I Don't have any vibration issues when going on hwy, at any speed. I can here my DS Binding when making greater than 90 degree slow turns..! Not sure about fast turns, as the car is too loud for me to hear it.

Anyone has the same issues?

Binding?? Really? Wow... I am trying to picture how that's possible.
Well, in any case, I can't offer any opinion as my brake ducting prohibits very tight turns -now I have the (relatively) poor turning radius of an Evo!!

[wrrrx]

Well, I thought about starting a whole new thread, but the last ACPT thread was like a hundred thousand pages, so who am I to quibble?

My review of the ACPT carbon fiber driveshaft for street driving;

Having installed the driveshaft with no real problems (other than my own lack of thoroughness in tying things up), I was really looking forward to using it in my daily driver.
I am happy to report that it is a very nice upgrade. While I may not have experienced some of the fantastic gains that others have reported, it does make the car feel "lighter" and quite a bit more nimble. The car revs faster and has much reduced drivetrain "lash" -which was my real impetus for the purchase.

I had reservations that there may be a downside to the quicker revs, but I have not experienced any. Also, I feared that it might not work well in concert with my finicky binary-switch of a clutch, the Exedy Hyper-Twin. (Despite what others say, IMO it's still a PITA in a street car!) Not to fear, it actually has made the Hyper-Twinkie BETTER!! Considerably so, in fact.

[wrrrx]

My review of the ACPT carbon fiber driveshaft for open track/HPDE events;

My next worry (I worry a lot- what can I say?) was how it would perform at open track events that I love doing.
Well, it's perhaps more of a mixed bag than street driving -or more likely I just need more getting used to it.
I'll start with the "Cons", as it were;
I admit that I'm not stellar at rev-matching (but suspect this is key to perfecting my use of the d/s at HPDE's), but I've never had problems with missed shifts or balky shifting -but I did yesterday at PIR. I had noticed that the shifting seemed less sure than without the d/s, due to the loss of rotating mass, perhaps?
Whatever the reason, I had, oh, 5 (five!?!) mis-shifts (very exciting 5th to 2nd! "Oh isht!!!") and at least 2 times where I couldn't "find" 6th, and fitted it back to 5th. This has never happened before and I'm sure it's the driveshaft. The difference in revving is VERY noticeable at the track, where you're running high RPM's constantly.
Hopefully this is just something I need to practice and I think I'll try "Uncle Scotty's" transmission ****tail to see if that helps.
(I have the TiC super shifter set and Kartboy short shifter, btw)

For the "Pros", the faster revving means you can use the AWD even better than before and really really REALLY launch out of the corners. (It also negates the lag from my FMIC and bigger turbo)
The car feels extremely fast (well, to be honest it was already extremely fast w/ 380whp! ) and "quick". It is a joy to really hammer on the car and have it respond SO quickly!! No sign of the mechanical "lash" that used to bug the crap out of me...

You do have to pay a lot more attention to the revs now -when upshifting from 5th to 6th on the front and back straights, I'm frequently at 7000 rpms already. When I wasn't paying atttn, it would shoot up to almost 8000 rpms, yikes!
I noticed a time or two when there were different vibrations coming from the driveshaft, mainly in the extremely tight LH turn (perhaps this is the binding laueddy and Rexstage1 mentioned?) It wasn't bad- although it made me nervous at first. Enough so that at lunch, I lifted the car and double-checked the bolts. All was good, wahooo! And that gave me enough confidence to REALLY hammer in the 3rd and 4th sessions.

So, as I said, it's not quite as positive as my "street" review, but hopefully I can adjust (my driving and possibly trans fluids) and reduce the downsides to running this at the track.

[VSGTS14]

def gonna be my next investment.