Dyno Questions
 

Had my 8 dynoed yesterday, made two pulls, on both pulls the horsepower dropped aprox 10 h.p. @ 6200 rpm then then began to climb until it reached aprox. 7500 rpm then fell about 12 to 15 hp then began to climb until it slowly tappered off. both graphs were almost identical and this happened at the same rpm's on both pulls. We did nothing except turn the dsc off. Is this proper procedure? What would cause this? Is this normal? Made 171 at the wheels. Car is stock w/ m flash. any help would be appreciated. Thanks.

is yours AT or MT?

considering it dropped at 7500 and then climbed again we can conclude that this is a high power car.

what you are seeing is the result of the car's PCM curbing power because it detects the front wheels not moving when the back wheels are. just turning off the dsc completly (10 second hold until the car with squiggly lines appears on the dash) is not enough to get a "correct" reading. you must unbolt the sensor on each back wheel and tie them up out of the way. so that it appears to the dsc/tcs/abs system that neither the front nor back wheels are moving. one sensor on each wheel. you need a 10mm wrench. even then it seems that on long runs the car will still notice something is wrong. so try to keep the runs as short as possible. having said all of that, 170ish is a normal number with the sensors in place. also if you are dynoing for tuning. make sure you do the runs the same way each time, the number is not as important as the percentage change with what ever mods you are intending to do. did you get a/f readings? what kind of dyno?

someone needs to post a DYI with pics on how to dyno this car

Thanks zoom 44 for the info.No we did not get a/f readings, we were just trying to get a base line before any mods.I believe it was a dyno jet dyno. Jercs it is a MT.

yep 170 is a good, not "wow that's amazing hp but correct and normal, number on a dynojet.

This post: https://www.rx8club.com/showthread.p...5&pagenumber=5 (2nd post down)... has a lot of info on the dyno I've found strange. It's agood read though. Has those power jumps you were talking about on his graphs too i think.