dynoed my stock mt 03 touring last friday and the operator asked what was the final gear ratio which at the time i didn't know. i just knew that he had to dyno the car in 5th gear for the 1:1 ratio. anyways he said he would just match mph with rpm to get the final gear. anyhow to make a long story short he figured the final gear to be 3.7 and the car dynoed max 229.6 hp with 221 torque. btw this was on a super flow dyno with 67 degree temp.

I know that my car has a final gear ratio of 3.54 now, so like the title ask, does it matter if it was 3.7 or not?

 

Yes it can/does...give this thread a read, there was a discussion on it yesterday in the FI section.

https://my350z.com/forum/forced-induction/306435-3-9-fd-with-greddy-tt.html

 

Yes. Dyno testing should be done in the gear with a 1:1 gear ratio. For the manual transmission this is 5th gear.

Transmission ratio x final drive ratio = total final drive ratio

or

1:1 x 3.538 = 3.538