Join Date: Jan 2005
Location: North Jersey
Motorcycle: 2005 GSXR-1000 (track), 2006 GSXR-600 (track/race)
Re: Low HP Reading, or bad dyno?
Comparing numbers from different dynos is not an effective practice.
You should have asked him what other 750's have turned on his dyno in similar conditions. When he said it was 130 degrees in the dyno room that for one thing indicates to me that he doesn't have a very well setup dyno room as it should have some better ventilation, but the point of him saying that is because an engine is going to make less power. Cold/dense air makes more power.....hot/less dense air is going to make less. 130 degree air is VERY hot for the engine to be ingesting.
He also should have been able to apply some correction factors to the dyno results to normalize them. To be honest, depending on the dyno a 750 is doing to make in the neighborhood of about 120hp give or take. A mid pipe is not really going to make much of a huge difference to that. Couple that with the far less than favorable conditions it was tuned under and I'd say 117hp sounds reasonable. Again, also depends on the type of dyno. If he was using a Factory Pro Eddy Current dyno for instance, those read noticeably lower than a typical Dynojet dyno.
The curve looks nice and smooth but you should have asked for a printout that showed torque and A/F ratio through the range, unless he didn't have the proper hookups connected.
"I never drive faster than I can see...besides that it's all in the reflexes."
CCS AM #478