1RevvinFC3S

I've been thinking about alot of **** I haven't heard about for FC's (mainly N/A's since I'm sadly without forced induction) and thought about carbon composite driveshafts. Well, I don't believe anyone makes a carbon driveshaft for the FC. But then I remembered that the RX-8 has a carbon composite driveshaft. Do you guys think it would work?

ForsakenRX7

No. the shaft would seem to me to be the wrong length. And then theres the issue with the splines even being the same. And I doubt that highly too. But why worry about a driveshaft. You shouldnt even be thinking about that until your puttin down enough power to snap stock ones.

Ryde _Or_Die

Think hes looking for lightweight? If thats what your looking for and your willing to buy a DS as expensive as I assume the RX8's is then look here:

http://acpt.com/driveshaft/index.html


They had a CF DS for sale on ebay a while ago so I assume they can make them for NAs.

Evil88rx7

anyone in the VA/DC/MD AREA have a FC driveshaft???

TURBO FC

the rx-8 driveshaft is almost twice as long as an fc driveshaft

1RevvinFC3S

INFIDEL!!!

BlackR1

There is no way the rx8 driveshaft is twice as long as the fcs. that would make it an almost 7 foot driveshaft.

They should be similar lengths, but the splines would be different, as well as the connector to the differential.

Many hot rod shops have custom driveshafts made and balanced to order. They can use a variety of materials...simple old tech but with newer materials.

88GT

Lets back up a bit here.. why do you want an 8 or custom CF drive shaft? In other words.. what is your goal here?

Parastie

Light weight is his goal. You'll lose less HP between the crank in the wheels using lighter parts, including a drive shaft.

Of course, it probably wouldn't be enough to make a difference, but it would be cool.

1RevvinFC3S

I'm trying to find anything I can to put my N/A FC into the 14's (and possibly even 13's with slicks) with nothing more than an agressive streetport or a half bridge. Of course it won't be easy so I've been looking for lighter driveshafts and flywheels as well as some other things to put me at roughly 200-250rwhp but remain streetable. Don't get me wrong though. I do realize that at this point it is a pipe dream, but I do intend on having something along these lines.

Kenteth

too much f&f and gt3... Its an interesting idea. When you can afford a RX-8 carbon fibre driveshaft, let me know.

1RevvinFC3S

Hmm, how this relevant to F&F? If you are refering to the second one, I never wanted to see it due to the bitter taste the first one left in my mouth. And GT3=Vidieo Game. I'm just using a few licks of common sense to put 2 and 2 together and say "Reducing drivetrain rotational mass will transfer power to the wheels more easily and much quicker" and said "well ****, the RX-8 has a CC driveshaft so why don't I get on the forum and see whether or not I can get some much needed info on whether or not I can use one on my FC because, for the most part, all of its members are helpful and supportive when needed and should spare me if I'm wrong and admit I'm wrong. But seeing that I don't know wheter I'm wrong or not, I'll see whats up". Thats just not very professional for somebody 4 years elder than I to steriotype me so damn quickly as yet another mindless drone that I so unfortunately share the same age group/air with. I'm not trying to come off as an *******, seriously Keneth. I'm just stating that I don't appreciate low blows to what little integrity I have in my unfunded, Turbo II-less, FD-less life especially when I'm stating legitamate possibilities.

cymfc3s

The RX-8 CF Driveshaft weighs almost exactly the same as the FC driveshaft. There is NO upgrade by swapping d-shafts.

Parastie

You should get the ultra light rotors and carbon apex seals from RB. That'll help you out.

carx7

iTrader: (31)

I second what Seth said. I don't know about the exact weights, but the weight savings on that would be negligable. The fact that the thing is less than 6" in diameter also is a good indication that any advantages in rotational inertia reduction would be neglidgable as well.

A light weight flywheel is a MUCH better option.

1RevvinFC3S

Okay, what about the CF driveshafts in that site that was linked by Ryde Or Die? That and a light flywheel would wake up muh powerless little mini-monster.

coldfire

iTrader: (1)

well...i think you would see more powergains through usual exhaust upgrades to tell you the truth. a good light flywheel is always good to have though, more so for responsiveness.

but if you have already spent your money on the usual, and have yet some more to burn, then go ahead with this CF driveshaft. it is actually probably the best way to increase driveline efficiency, but that said i doubt it will be an incredible amount.

as for getting into the 13s...well, that **** ain't going to be comfortably street drivable

incubuseva

iTrader: (13)

what about renesis rotors? they have higher compression... or are they still experimenting w that?

1RevvinFC3S

Hmmm, I also believe they are lighter as well.... I don't know (the hamster is starting to run).

Oh, coldfire, I was talking about 13's with slicks, like a 13.9 or something. I was hoping for 14.0-14.5 on street tires. Thats still enough to take some **** out. Of course I'll need a nice wide tire (like 255-275's) but not a drag radial. I want to keep it twistiable (if that is even a word).

Impreza2RX7

A CF driveshaft is one of the last things you would want to do.. It's not like a flywheel where the mass is spread out, driveshafts are smaller in diameter and any change in weight would be negligible..

coldfire

iTrader: (1)

agreed^

yeah, get a good flywheel first. it will just help the overall driveablity

First gen man

iTrader: (24)

Any body actually confirm it doesn't work? No way to shorten it? Change input shaft/diff flange?
And it seems everyone missed the fact that the carbon driveshafts twist more, reducing drive train shock. That's the sales pitch anyways.

iamsisyphus

The RX-8 driveshaft is noticeably lighter. It think it could be cut down and a replacement piece from the aluminum driveshaft offered by Mazdatrix glued in. Get it balanced and installed and the OP and me would be the envy of our club because it's cool.

Doug

rotary#10

iTrader: (38)

How did the modification and swap go ?

Dak

At this point I don't really see any reason to do what was discussed in this thread. Since it is confirmed the Rx-8 shaft is too long. Even though they are cheap on Ebay you still have to get a driveline shop involved to cut, reglue and balance the shaft. Which will only work if you are running a TII gearbox in a n/a car as the RX-8 shaft uses the same yoke diameter/ spline count as the TII/FD and rear flange pattern of a n/a FC. Not sure what they would charge for all that if they would do it and if they did you still have non-replaceable U-joints. If you have a TII or n/a with all matching driveline parts things just get more complicated and they may not be willing to deal with that. IMO if you want a carbon fiber driveshaft have one custom made by a reputable driveline shop. This also gives you the benefit of having replaceable U-joints which the Rx-8 shaft does not.
I used these people Precision Shaft Technologies - The Leader in Performance Driveshafts (pstds.com) when I had my custom aluminum shaft made for my RX-8 rear end conversion. IIRC I specified the conversion U-joint I needed and I supplied my own yoke and flange that I sourced from a company found in the information in this thread:
How to make your own aluminum or carbon driveshaft - RX7Club.com - Mazda RX7 Forum

Also what wasn't known when this thread was started but is now, is that the RX-8 uses the same diameter yoke and spline count as a TII or FD gearbox. It uses the same rear flange bolt pattern as the n/a FC.