Bad day at the rollers

[Skywalker]

Also looking at the sheet my run ended at 7200rpm

 

[thebrasso]

Also looking at the sheet my run ended at 7200rpm

No wonder its a bit down then! On my car it was producing 169.3bhp at 8325rpm, but at 7200 rpm would have only produced 158 ish.

 

[Gaijin]

Here's the plot of mine - Whereas the power figures are definately on the low side i'm pleased with the linear power delivery and smoothed crests and peak compared to the other 5dr VTI's.

I think mine with modifications works out about 17bhp over stock which for a VTEC engine i'm fairly happy with.

Definately after a second opinion though.

Even after all that preaching, the nobster got my tyre pressures wrong.

 

[Gibbo]

Hi there

From looking at those figures they all seem to be 12-15% below what they should be.

Now I think its kinda strange that a FWD manual cars transmission are in the regions of 12% loss.

So all those figures your all getting seem pretty accurate for actual power at the wheels. If you add 12ish percent you will find your more or less at the correct crank power.

So my guess is either the rollers were reading low or the operator somehow manage to make it report crank readings which are clearly at the wheels readings?

 

[TomO]

its also odd that on the graph that you dont have a line for power @ wheels and power @ fly. makes me think gibbo may be right

 

[evilowl]

Now I think its kinda strange that a FWD manual cars transmission are in the regions of 12% loss.

So all those figures your all getting seem pretty accurate for actual power at the wheels. If you add 12ish percent you will find your more or less at the correct crank power.

So my guess is either the rollers were reading low or the operator somehow manage to make it report crank readings which are clearly at the wheels readings?

FWD transmission losses are closer to 18%, and the Dyno Dynamics plots show power at the wheels, not fly so that explains why you all appear to be down on power.

From my dealings with various RR's, I have found the Dyno Dynamics ones are the closest to real power figures compared to other RR manufacturers. You also cannot compare dyno figures between manufacturers or (in all honesty) dyno runs on the same dyno that were done on different days as the ambient temps will be different , also air pressure and tyre pressure come into the equation.

You also have to remember that not all cars are created equal (when comparing to stock) and how they have been run-in and looked after will also effect power output.

But at the end of the day, RR's are a tuning tool. No more, no less. You can't race a dyno

As long as the car feels good on the road that's all that matters. Your "butt dyno" is far more accurate

 

[Matt82]

the dyno runs ive done have been good at showing up irregularities in the power delivery, so in a sense a diagnosis tool.

the only reason i did it on the golf was to see how healthy it still was