I have a 91 Formula TPI 5 Speed... From what this board says, it's got 3.08 gears...

I understand that higher number gears will improve take off speeds but lower top end speed... and vice versa...

My question... I would like to see what differences someone that had a 3.08 got when they switched to a 3.73 or 4.11

Numbers, timeslips, etc...

Gotta beat a few mustangs

Raf

I went from 3.23 to 3.73 when I was an auto and I gained 3mph and cut .5 seconds from my ET. Was still able to exceed 140mph.

Now that I have a T5, the car is faster but I haven't taken it to the track. It has lost top speed though, I can only hit 130-135mph at 5K in 5th gear.

Cool, thanks for your input...
I have a 10 bold... I see another number associated with these rear end gears (besides the 3.73) what does that refer to and which do I need? Thanks,

Raf

That is probably the carrier. There are 2 and 3 series carriers, basically you get a gear set depending on the carrier that you have, 3.08 and lower numbers are 2 series and 3.23 and higher numbers are 3 series.