Hi there. I was just wondering if anyone has attempted to improve rear wheel power by increasing drivetrain efficiency, and if so how much improvement have they gained.

By efficiency I mean. Base drivetrain loss is 20% or there abouts (from what I've read on this board, I have no idea personally). Replacing things like, driveshaft, wheels, brakes and stuff like that to lighter and therefore more efficient components. I think the stock shaft is 20-22 pounds, and the 1LE one is 11, carbon fiber is 8 or less. Therefore replacing the stock steel shaft with either of the latter to would yield benifits. Less rotating mass = less power lost on the way to the wheels.

Thanks, Im tired, so sorry if this isn't too clear.

 

It's very clear and has been done for LONG TIME.

Aluminum wheels, aluminum driveshafts, carbon fiber driveshafts, smaller flywheels, etc., etc.

 

Acutally there is not that much difference in stock steel driveshaft vs. aluminum weight. When I put on my aluminum driveshaft I weighed them to see what the difference was and it was only like 4 pounds or so. But, since this is rotating mass it makes a much bigger difference by having less weight that the engine has to spin. I don't know why I am saying this but what ever.

 

Dont think i got my question across correctly. I was asking HOW much, % wise, did people gain from these mods? thanks

 

A good place to start is synthetic lubricants. Various people have measured that on a dyno and claim anywhere from 5 to 10 RWHP. Even at 5 RWHP on a 200 RWHP car, that's a 2.5% improvement, for almost free, doing something (regular fluid changes) that you should be doing anyway.

Other things that help without necessarily replacing parts: drive shaft alignment, make sure the brakes don't drag.

 

Your brakes will always drag. That just comes with the territory of disc brakes.

 

If your brakes are dragging to the point where the wheels won't spin freely, you've got some problems that need taking care of

 

Lightweight components won't make a difference.

Yes, less mass will mean that the components can be accelerated with less power, but once they are moving, mass has no relevance. A lightweight driveshaft may help acceleration, but won't affect peak HP or torque. It's just rudimentary physics. once a mass is moving, kinetics are in effect. It's the same with wheels, tires, axles, etc.

The areas of concentration should be drag and power transmission efficiency. Hypoid gears create more frictional losses than bevel or spur gears. Any gear arrangement has loss due to the sliding between gear teeth. Hypoid gears are among the worst. Not as bad as worm gears, but not as good as bevel gears.

Your transmission also has losses from gearing, clutches, pumps, and other parasitic loads. Reducing friction in these devices will liberate more power and efficiency than lightweight components. The lightweight parts will only allow faster acceleration.