my dyno results.
- Thread starter dan_ep82
- Start date
white-ep82
Member +
that on the k24? 14.5 psi = 1 bar doesnt it? good results mate!!
speedvision
Member +
when u have a chance upload the dyno sheet
is this the k24 turbo ur running right?
sam
is this the k24 turbo ur running right?
sam
speedvision
Member +
i take it your car was standart, thats nearly 40% power loss
is there sand in your gearbox or something? 
ChrisGT
Member +
i take it your car was standart, thats nearly 40% power loss
Its not that standard no, was running 0.7Bar on the ct9. And I guess everyone had sand in their gearbox on the day!
Chris@CCM
Member +
i dont agree mate if its a good dyno the fly wheel power should be fine . as so many things can change the wheel hp . the guy at the dyno i go to told me all about it one day and said a few years ago he would have said the seam thing about wheel hp but now days its all changed .ill ask him more about it next day im up .
riko666
Member +
well I mean how much faith can you put into a figure that is by all means, calculated or "estimated" from a given figure (wheel horsepower)?? On a rolling road Dynamometer the "Drivetrain" loss is calculated by the remaining force of the wheels turning the drums when the car is stuck in neutral after the power run...Now think of the inconsistencies - you have internal friction resistance of the drum, you're going to have friction loss between the tyres and the drum as you cannot guarantee no slip whatsoever, and so on...
I mean, not to discredit the guy at your Dyno, but I very much doubt he would say something that would criticise the very device on which the business is based on. In my opinion, Flywheel Horsepower can only ACCURATELY be calculated when the engine is bolted to an engine dynamometer, as the power is being taken from the flywheel. In that respect, using a Rolling Road or Hub connected (much more accurate as it does away with insoncistencies of traction and mimimal losses through the flexing of the tyres etc...) Dynamometer, will give a more accurate reading of the power at the wheels as in effect, the wheels are driving the Dynamometer, not the flywheel.
It is also relative though...the calculated drivetrain loss would be the same level (well, depending on the car's ACTUAL drivetrain loss) for any car on the same dyno, so the inaccuracy of the flywheel horsepower will be the same for that particular dyno regardless of car.
There's lots of methods to calculate drivetrain loss...but each sort of continent has different "estimates" for Drivetrain loss - Australia for example claim about a 15% loss, USA about 20%, UK something silly like 30% and so on...I mean, I cannot say for sure, I'm just using my own theory to guesstimate the above, and I think it makes sense. Plus if you research, you will find the answers to this as well. It is why the States and Australasia SOLELY quote power figures, as WHP. Only manufacturers really have the right to quote Flywheel Horsepower, as they'll have it strapped to an Engine Dyno
I mean, not to discredit the guy at your Dyno, but I very much doubt he would say something that would criticise the very device on which the business is based on. In my opinion, Flywheel Horsepower can only ACCURATELY be calculated when the engine is bolted to an engine dynamometer, as the power is being taken from the flywheel. In that respect, using a Rolling Road or Hub connected (much more accurate as it does away with insoncistencies of traction and mimimal losses through the flexing of the tyres etc...) Dynamometer, will give a more accurate reading of the power at the wheels as in effect, the wheels are driving the Dynamometer, not the flywheel.
It is also relative though...the calculated drivetrain loss would be the same level (well, depending on the car's ACTUAL drivetrain loss) for any car on the same dyno, so the inaccuracy of the flywheel horsepower will be the same for that particular dyno regardless of car.
There's lots of methods to calculate drivetrain loss...but each sort of continent has different "estimates" for Drivetrain loss - Australia for example claim about a 15% loss, USA about 20%, UK something silly like 30% and so on...I mean, I cannot say for sure, I'm just using my own theory to guesstimate the above, and I think it makes sense. Plus if you research, you will find the answers to this as well. It is why the States and Australasia SOLELY quote power figures, as WHP. Only manufacturers really have the right to quote Flywheel Horsepower, as they'll have it strapped to an Engine Dyno
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jamesgtturbo
Member +
still surely whp is more accurate?