Opel Speedster on the rollers z22se
I found this while looking through the internet, VX220 Z22SE
Click below to watch video:
http://www.verboom.net//images/speedste ... ynorun.mpg

So the values are:
126HP at around 5500rpm (factory 147HP at 5800rpm)
183NM at around 4000rpm (factory 203NM at 4000rpm)
So roughtly that would translate to 15% loss, which is quite acceptable. If you use the guidlines from the document on Puma Racing it would translate to around 151HP, which is feasable.
Next day, I did the more interesting experiment. How would my own measurements hold up to the rollingroad run. I wouldn't expect the figures to be exactly the same, but the shape of the graph should similar. The results were very encouraging:

So even the vaules compare pretty well to the rollingroad test. The problem is that the rpm values are a bit off, which is due to the way the measurement is done. But now that I know it curve form is the same, I can try and optimize this way of testing. Will be a lot cheaper and much more convienent than to do a rollingroad test after each modification.
