excitid

If you dyno your car at 100hp how much would it really be making at the crank.

1stGenCRXer

Power loss breakdown to the wheels depends on the model and condition of the parts, but you have:

windage in the engine oil pan
clutch engagement losses
transmission bearing drag
oil viscosity losses in the transaxle housing
mechanical losses due to gear ratios and friction
friction losses in the drive axles
drive hub bearing losses
and finally the rotating inertia of the brakes and tire/wheel combinations

On a honda, you can expect about 12-15% of the power to be lost in the drivetrain. On some RWD cars you can expect higher losses, same with AWD cars. Race car builders go to great lengths to eliminate these losses without hurting reliability, so they may have less loss in the drive train.

jaje

normal fwd cars (without lsd) get 12-15%...the sentra spec v is 18% which calls in doubt whether it truly makes 175hp

normal mr cars get 14-16% due to the fact it's similar to a fwd setup

normal rwd cars get 18-20%

normal awd cars get 20-23%

it also depends on how high the hp application is...b/c more hp the more durable the tranny/drivetrain needs to be resulting in more loss...so high hp cars tend to lose more due to the heavier duty components

ronaldmcdonald

Hmmm..so what are some of the more affordable and reliable ways to get/not lose power to the wheels? I would think something like a Quiafe LSD (they advertise some 5% more power to the wheels iirc) should help, but is there other stuff I ought to check out or inspect? Since our CRX's are at least 11yrs old, what would be the parts to look out for in particular?

1stGenCRXer

If you're that concerned with it, new bearings in the transaxle housing will help remove excessive clearances, beyond that and a Limited Slip like you mentioned, lighter wheel/tire combinations [and brakes if you're really concerned] are about the only other thing you can change.

ISP James

lighten flywheel and tougher clutch :thumbup:

ronaldmcdonald

About unsprung weight, would it only matter in the earlier RPMs in termns of transferring power to the wheels, or does it effect the entire powerband. I would think unsprung weight probably wouldn't matter so much after there's intertia pushing the extra weight, but I'm just guessing.

brtecson

The engine is transferring power to the wheels through out the powerband, so yea, it does matter in the high rpms. Think about it, when the wheels are spinning faster, you are moving the wieght of the wheels faster, therefore more power is used in high-rpm to account for drivetrain losses.