Ok so i was doing some maths and am trying to figure out how fast i'm supposed to be able to go in each gear and compare this to how fast I actually do..
Now i'm fully familiar with the math and how this is done. rpm * wheelcircumference / (gear ratio * final drive) then convert minutes to hours and inches to miles.. so for 1st gear, 8800rpm/60 * PI * 24in/(12*5280) / 3.133*4.1 = 49mph
But for some reason my fuel cutout is happening at 41 mph. Now i really dont run it up to the limit very often for obvious reasons but i know that i can only make it to 41mph in first gear. Also by the same calculation i should make it to 75 in 2nd but only get 60..

Any ideas? am i missing something really big?
My tires would have to be only 20 inches tall in order to make 1st end at 41.

Thanks for any help.

 

There is an extra reduction in the gearbox apart from the final drive... That is part of it... but I am not sure why you only hit 41... my AP1 gets into the mid 45+mph range in first (on the rev limiter)

 

i dont know about 1st gear but second is about 62

 

there is also a secondary gear ratio that you left out.

 

Oh!! yea secondary reduction. Ok that fixed it.
8800rpm/60 * PI * 24in/(12*5280) / 3.133*4.1*1.16 = 42mph
and for second... = 64mph

Thanks guys. Peace of mind is so nice.

 

http://www.turnzero.com/technical_re...ear_calculator

 

What is the secondary reduction? Output shaft?

 

wait a minute........how come I can only hit 38mph before the rev limiter flashes in first gear?? Also I hit 88mph in 3rd instead of 90mph or so b4 the rev limiter flashes

 

I'm not sure if you have an ap2 or not but i dont have a indicator light. but maybe that light is coming on a couple hundred rpm before the fuel cutout..