Originally Posted by radar
Originally Posted by BSB67
Have you done the mph/tire dia/gear ratio math to determine rpm?

The reason the power is climbing at the claimed 5500 rpm is because I don't think 75 mph = 5500 rpm. I get something more like 4600 rpm.


If I hadn’t heard him bounce off my limiters I would be asking the same question. The first time I was majorly freaked out because it sounded hreat then broke up a little and he let off.

After making this post I had the same thought- looking at the sheet again. I had figured that the difference in 5000 and 5500 would be how wide 500 rpm was on the X axis. But no- that’s not time it’s mph so things happen faster on the right side of the paper. So all the dyno sheet tells me is that my torque curve was vastly increased by tuning the spark map. I also pulled up an internet gear, ratio axle ratio, & rpm to mph. Even if my 27.25ish tall tires grew to 28” the numbers don’t make sense unless the B&M converter is just mush and only spins the trans 75% of engine speed? Like I said it’s my first hotrod with two pedals.


Here is my conclusion, one or more of your data are simply wrong, and your power curve is not what you think it is when you think it is.

If you tuned for improvement, fine. But you're on here asking about making sense of bad data.

Your buddy needs to fix his stuff, or you need to go to a different dyno that is working properly.

I will bet your peak power is below 5500, and best et shift rpm 6000 or less.