I was browsing rotary extremes web site and came across this...
http://www.rotaryextreme.com/fddrivetrain.html
Seeing as the stock drive shaft weights approximatley 17lbs, and REs weights 11lbs; I would imagine a nice little gain in acceleration. I'd like to hear some of the more experianced forum members oppinions on this

-Dan

 

Nah, the diameter of a driveshaft is too small to really see any huge inertia type gains (unlike wheels for example)

 

A lighter driveshaft can be beneficial. However, the stock driveshaft is already very light and shaving off 6 pounds is not worth the time and expense in my opinion.

 

From what I gather, it is basically the same idea as the lightened flywheel. Less rotational mass makes for an engine that is easier to rev.

I know others may argue that it could gain horsepower. I don't believe this to be the case. It will however show up on a dyno sheet as an improvement but only because the wheels are now easier to spin. Actual engine horsepower will not be affected.

Carbon fiber and aluminum driveshafts are going to be commonplace on most new cars in the years to come. Examples of cars that make use of them already are the Nissan 350z and the Lexus IS300, respectively. The only vehicles that would ever want a heavy steel driveshaft would be off-road vehicles. The reason being is that they are strong.

Hope that helps.

 

here's a way to test it without actually buying it, if you have a PS2, and you know someone that has (or you own) GT4, take a completely stock FD, drive it in the 1/4 and on some tracks, and then add the lightweight driveshaft only, and re-drive everything. the physics engine in that game is extremely good (or so i've heard, i have GT3 and the driveshaft helps a ton on all of the cars), so it should give you a rough idea of how much it'll help out in real life

 

^^^^ that's the funniest thing I've ever heard!

The 6-speed RX-8 has a cabon fiber driveshaft, and I've seen one available for the FD as well

 

https://www.rx7club.com/3rd-generation-specific-1993-2002-16/carbon-fiber-driveshaft-downsides-239133/

 

You have to be joking

 

the funny thing is, i dont think he is joking.

 

Not really true. Flywheels spins rapidly with a very high rpm increase, which makes light f'wheels increase hp to the wheels in lower gears.

Driveshaft spins at 3 or 4x wheel speed, and slowy increases rpm during a 1/4 mile run, vs flywheel in 1st or 2nd. It's rotary inertia is also very low for stock d'shaft.

Bottom line, you save 6 lbs for about $900. Better to jog a few miles a few days.

If you have 1500 hp and 1000 ft-lbs to put down, there may be some advantage for the pro racers.

 

If you read the thread I posted, turbojeff weight the stock shaft and it was 14lbs. So, the savings are even less.

IMO, the only reason to upgrade the driveshaft on a FD is when it's either broke or you are doing an engine swap which can't use the stocker.

 

Yep. Not worth it unless you are racing at a national level, where a thousanth of a second matters.

 

i wrote that at like 3am, of course i was joking. dry, synical, sarcastic sense of humor, very few people, even in every day life can tell if i'm serious or joking

 

That's why we have those things called "smilies" to let people know you are joking.

 

at 3am, i didn't really wanna do the extra three keystrokes to make a smiley, but i guess i'll have to make the extra effort from now on to stop people from bustin a nut everytime i try and make a joke

 

In that case, don't make any at all.