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Difference between power @ fly and @ wheels



  172 Credit crunch edition
Had my cup r/r a little while ago and it made 178.2bhp at the flywheel but only 148.0bhp at the wheels now that seems to me like an awful lot of power being lost through running gear?? (30.2 bhp) Does it or not??
 
  Clio 172 phase 2 cup
Yeh its a percentage loss so the more power you have the more power you loose too. The scooby we have looses 75 bhp through the transmission .
 
  vers le haut doigt milieu
its a machine, it never ever gonna run 100% efficient. If you figure out how to do it you will be very very rich...
 
  172 Credit crunch edition
Im just wondering as i saw a stand at a car show a while back and they had a product called activ8 friction reducer, It supposedly reduces losses through transmission. The guy done a few friction test and yeah it did seem to fair up an awful lot better than the likes of slick 50 etc etc. Just a thought.
 
  Clio 172 Cup
Im just wondering as i saw a stand at a car show a while back and they had a product called activ8 friction reducer, It supposedly reduces losses through transmission. The guy done a few friction test and yeah it did seem to fair up an awful lot better than the likes of slick 50 etc etc. Just a thought.

Looks like b**locks to me
 
^
never heard of anything like that before, if it was any good everyone on here would be running it.

- as he said, looks like b*llocks.
 
  172 Credit crunch edition
Nah it doesent look like b*llocks! It looks more like a bottle shaped thing with a spouty type-thing on the end. Hmmm the stuff inside well thats just flat really oh and really runny.
lol
 
  Lionel Richie
you car hasn't got 178.2 at the flywheel, no one's car has whatever power they "claim" at the flywheel its a CALCULTAION done to the power recorded at THE WHEELS

you can state you have 148 AT THE WHEELS as thats where the power being transmitted is recorded
 
To increase power at the wheels you need to remove/modify items which are strangling power from the engine.

Lighter flywheel
Thinner gearbox oil
Remove unnessary things from fan belt etc.. list goes on Probably loads more just cant think of them
 
  RSC 182 Cup
Here in Australia all the chassis dyno figures are usually quoted "at the wheels" - I've noticed it seems to be the total opposite for you guys?

My stock 182 Cup got 103kW at the wheels which works out to 138hp.

There are too many "fudge factors" involved with converting the measured wheel power to engine output IMHO.
 
  RenaultSport clio 172 mk2
They put it on the chassis dyno and they measure the power at the wheels, then estimate what it is at the flywheel. There are ways to get a good estimation, but it is only an estimation.

The only way to know for sure exactly what it is is to measure the same engine on the same dyno at the flywheel and at the wheels. That has been done, and the figures are available. Your dyno may have simply used the "standard" power loss estimate figure of 17%. That is about right for a rear-whhel drive car with a diff that has to turn the drive 90 degrees. Four-wheel drives usually have higher losses because there's two diffs. Front wheel drives usually have a bit less. Its probably about 15%, though all those numbers depend on the gear you're in.

Assuming its 15% your car which measures out at 148 bhp on that dyno would produce about 174 bhp at the flywheel on that dyno.

But, unfortunately, you can only compare that number to other cars dynoed on that particular dyno. It'll be similar number on other dynos, but dynos do vary.
 


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