OcUK Rolling Road 9: Photos + Graphs

WE GET IT, you don't like the rollers. :rolleyes:

The_One said:
Powerstation are a good company the fault lies with the maha rolling road and how it calculates losses.

Freedom of speech and all that dont drop the dummy
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I haven't dropped a dummy, just it really narks me when someone comes into a thread, completely ignores everything that's said and goes on a power trip about how everything is incorrect, when it clearly isn't.
 
The_One said:
Powerstation are a good company the fault lies with the maha rolling road and how it calculates losses.

Freedom of speech and all that dont drop the dummy
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point is

that the at the wheels figure will be lower due to the increased drag created by the two contact patches.

BUT

the dyno measures the drag on the coastdown, and uses this to create a correct power at the fly figure.

Look at it this way, the power at the fly figure is corrected to account for the extra drag caused by two contact patches, the power at the wheels figure isnt.

Stock power for my car is 280 PS. Which equals 275.3bhp

mine had 276.5 bhp !!

so much for over optimistic dynos.

The_One said:
Its way out

S2000 should hit around 200 RWHP
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ignore the wheel horsepower figure. We dont use that here. Only figure worth looking at is the fly figure, for which the S2000 is about right.

Tim said:
whp figures look out on the S2000 too, please don't kill me:(
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WHP figures will be out due to the dyno. The figure you're looking for is the fly figure

heck, dyno dynamics dynos (which some tuners swear are the only accurate dynos) dont even show you WHP.
 
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MrLOL said:
WHP figures will be out due to the dyno. The figure you're looking for is the fly figure

heck, dyno dynamics dynos (which some tuners swear are the only accurate dynos) dont even show you WHP.
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Aye. To be fair the engine power figures for the EP3 and S2000 are bang on.
 
exactly thats what you need to be looking at

nobody quotes power at the wheels in this country

Lopéz said:
As opposed to what - FWHP?
Where's the recent obsession for stating which wheels are generating power come from? Is it an American thing?
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yes its an american thing. Nobody in the US quotes power at the fly, its all power at the wheels, and the americans liked their RWD so you'll find them quoting RWHP all over the place :)
 
The_One said:
No your missing the point all a rolling road does is measure WHEEL power.
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Wheel power with increased drag caused by 2 contact patches

you dont have 2 contact patches on the road. As ive already said, the power at the fly figure is corrected to account for this

the power at the wheels figure isnt.
 
The_One said:
Have a look on the net for how a rolling road works mate and what expected losses are for a fwd car.

Like i say if you want to think your st220 is 240bhp go ahead :)

Just never take it near a dyno dynamics rolling road because you will be gutted and walk away unhappy :)
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I'm not saying weather I believe it is or not, but I know it's more than 180, I can tell you that for sure, and that is what it would be based on the figures you have mentioned in this thread.

The_One said:
Powerstations rolling road calculates drivetrain losses too high. The wheel figures are correct. The fly figures are way overinflated.

Drivetrain losses on a fwd car is meant to be about 15%
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So what are you saying then, all of us that have put our cars on Power Stations RR, have cars making 'considerably' less power than they are supposed to at stock? ...that seems unlikely.
 
The_One said:
No your missing the point all a rolling road does is measure WHEEL power.
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explain this graph then ?

RemapGraph.jpg


it doesnt even mention the power at the wheels. If thats all a dyno does, where does it get its figures from ?

You're completely missing the point of the dyno, and why it does the coastdown after the run.
 
So the engine power looks ok, but is there an option on the Maha roller to give a more accurate whp figure? ie. simulate only 1 contact patch or something?
 
Tim said:
So the engine power looks ok, but is there an option on the Maha roller to give a more accurate whp figure? ie. simulate only 1 contact patch or something?
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No, not that I'm aware of, short of parking the car on top of one roller...but that would still be incorrect due to it being a small contact patch, although it'd be more accurate WHP figure than with the 2 contact patches.

EDIT: Tim, you've been many times before, surely you knew this before? :)
 
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thing is, that dyno is not designed to give out accurate at the wheels figure

nobody in europe quotes power at the wheels. Thats an american thing.

*edit*

here we go. American dyno with one roller

http://www.youtube.com/watch?v=p2cyb_XoSF8

As already said, american dynos will have one contact patch to quote an accurate at the wheels figure, as thats what they measure. The maha dyno is german, and in europe all the tuners work on power at the fly, and thus the maha is constructed to give accurate at the fly figures, not power at the wheels figures.
 
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InvaderGIR said:
No, not that I'm aware of, short of parking the car on top of one roller...but that would still be incorrect due to it being a small contact patch, although it'd be more accurate WHP figure than with the 2 contact patches.

EDIT: Tim, you've been many times before, surely you knew this before? :)
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I've never noticed how far off the whp figures are untill I ran on a Dynojet. Now I know it's the 1 vs 2 contact patch thing... As said though, the engine figures look spot on:)
 
thats all you need to look at. best way to think of it, is that the power at the fly figure is corrected to account for the 2 contact patches.

Power at the wheels isnt.
 
That's the thing Mike. It is low. On a Dynojet it makes 159whp.

dyno2.jpg


Engine power is bang on the money though:)
 
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