New range of carbon propshafts available soon.
http://www.rotaryart.uk.com/acatalog/TORQline_.html
http://www.rotaryart.uk.com/acatalog/CTG-TJuner.pdf
http://www.rotaryart.uk.com/acatalog...g_2drx7_2dprop

Has anyone on here use any carbon props?

 

$2000? Yeah....

The stock driveshaft is actually quite light. The only reason I could see running a CF driveshaft is if you were doing VERY high horsepower drag racing, and wanted a driveshaft that would splinter if it broke for safety reasons. Besides that, it's a waste of money.

It's neat that they have it, though.

Dale

 

I've seen them for 950 on some sites...

 

I have heard of cheaper ones but thought they were having breakage problems.
Anyone on here used them?
What makes are there out there?

 

Try PM'ing "ErnieT". I believe he will be using one on his new setup.

 

Didn't JimLab refute any claims that you will see a noticable increase in engine responsiveness/horsepower because the stock driveshaft is so light and not too large in diameter, and that the only purpose of having a light driveshaft is really to remove weight from the vehicle?

 

Probably, but the main goal of a CF driveshaft would be for high powered drag launches as it will flex and then retain it's original form better for those applications.

 

Does anyone make a carbon fiber ppf? Just curious.

 

Why would you want a C.F. PPF? That's probably the last place you would want C.F.

 

Here's the thread you're prob referring to where Jimlab spoke about 'em:

- https://www.rx7club.com/v-8-powered-rx-7s-299/custom-driveshafts-310681/

And here are two threads where some of the forum gurus (including Max Cooper) essentially said the same thing:

- https://www.rx7club.com/3rd-generation-specific-1993-2002-16/carbon-fiber-driveshaft-59057/
- https://www.rx7club.com/rotary-car-performance-77/carbon-driveshaft-180476/

~Ramy

 

I tend to agree. Thankfully I haven't seen any (custom or otherwise) in use.

Dave

 

Why? Isn't carbon fiber intended to replace structural steel? Seems like a better use than dashboards.

 

about the driveshafts, the main reason to replace the OEM with a CF one would be:
1) safety
2) weight
3) throttle response
but if the OEM driveshaft is already lightweight and 1-pc, then 1) and 2) are already taken care of. so the only other reason to get one (other than just "i have a CF driveshaft") would be for safetly. a lot of STi guys are going to a 1-pc CF driveshaft because the stock one is 2-pc and the CF is 11-13 lbs lighter. but for RX7's, unless you're building a high-power drag car, or a track car with lots of safety in mind, or just trying to blow money... there's no reason to get one. personally, some day i'd like to get one just for safety reasons, but to each their own.

btw, ACPT makes them for STi's and i'm pretty sure RX7's, too (they have a pic of a drag 3rd gen on their website). the ones for STi's are about $1200 retail, and i'd imagine RX7's are a little cheaper because they've been around a bit longer.

 

This is the only reason to replace one on an FD:

https://www.rx7club.com/showpost.php...0&postcount=24

 

It's not a drop-in replacement for any material. Carbon Fiber composite requires much more detailed design or prototyping, and in the case of a complex shape of a PPF it's going to make it tremendously expensive. Without that detailed design, it may actually be less strong and heavier than the welded steel part.

Another issue is that CF is more compliant (less rigid) than steel, which is one reason it's ideal for driveshafts. It's also one reason why it's not good for PPFs.

Dave

 

I have the ACPT CF driveshaft and didn't notice a difference like I did when I did the lighter flywheel. The weight of the stock is 14 and the ACPT was 11. Another reason would be the serviceable u-joints on the CF shaft since I don't think you can on the stock shaft. Not 100% sure about the stock shaft, I just remember a post or e-mail from the big list days that the stock shaft's u-joints are serviceable.

Tim

 

I was also told the stock joints are not serviceable by the shop that is making a custom short shaft for my 20b project.

 

CMonakar, are you having them make the shaft out of CF while you're at it? What company didja go w/?

 

I know that Vividracing have the CF for sale in USA

http://www.vividracing.com/catalog/p...oducts_id/9398

They claim that if you change the shaft you can get 5% more power.

 

Last part should have been

the stock shaft's u-joints are NOT serviceable. Sorry for the typo.

Tim

 

Yea I think we all realized what you were tryin to say Tim

~Ramy

 

Fitted the first prop yesterday and it was fine, just needed a small amount shaved off the joints as there is only 2-3mm clearence.
By fitting it we came up with version 2, which we are looking in to. Will make a big saving in wieght over version 1.
Version 2 could save up to 36% over stock prop.

Although even a 1kg saving dosnt sound much in terms of inertia, that equates to 50kg of wieght saving at launch. So you can the obvious advantage, especially if we end up with a 3kg saving.
You then have the added benfits of being kinder to you diffs, g/boxes, braking become better and safer if it were to break, metal ones have been known to come through the floor pan or dig in to the road/track and flip the car.

 

Shortened props can be made to order

 

Just spoken to them and version 2 looks like go.
Will be approx 37% lighter than stock, will be a smaller diameter than version 1, new ends are going to be purpose made as oppossed to what is available.
Will make it slightly dearer but worth the addition savings in size and weight.
http://www.rotaryart.uk.com/acatalog/TORQline.html

 

So are they out yet? What is the final weight? It would be interesting to see how it compares to the ACPT shaft.