Originally Posted by SlowerOne
That's 75mm/rev - are you sure that's for 10.5? Looks more like a 13.5 ratio to me - can you confirm? Thanks.
In 13.5 I was at a 50 pinion.
It sounds high, but there isn't much total timing.
I ran 50-84 at my local track with ver. 200, max boost, 0 motor, 0 turbo with very good success. Only .3 drop off after 8 minutes.
You can bump the motor timing up and turbo with the 10.5 and drop the gear to 40-80, but it dropped off more at the end.