midwestjunk

iTrader: (2)

currently i have a 12 bolt with 4.10 gears and a T-56 6-speed. I'm looking at putting a th400 trans in it soon and i want to install a spool. should I keep the 4.10 with the auto trans or change the gear ratio while i'm in there?

heres the specs:

3460 race weight.
650hp @ the wheels with t56
this is a nitrous car
prolly shifting around 7,000rpm
28x10.50 hoosier slick

not sure what else is a factor in selecting the correct gear ratio.


should i keep the 4.10?

Alex41

iTrader: (14)

No more than 3.70 with the nitrous. Otherwise you may run out of gear.

LS1RedZ

iTrader: (19)

I think a 3:73 gear would be perfect.

midwestjunk

iTrader: (2)

what info do i need to figure out an exact gear that would be perfect. is there a chart or something that i can use with tire size and what rpm i'd want to cross the traps at or something? say i shift at 7k rpm, when i'm goin thru the traps im sure i could hold it thru at like like 7,200 if i had to.

Bob@BruteSpeed

iTrader: (16)

http://www.richmondgear.com/112901.html

There are a lot of gear ratio calculators on the internet. The one here might help you out. Bob

midwestjunk

iTrader: (2)

according to that It says with 650hp at 3460 race weight and 28" tall tire crossing at 6,600 rpm with a 4.10 gear. If i spray the car more and made 750hp it would go through the traps at 6,900rpm. that seems fine to me. I'm gonna keep the 4.10 gear.

Bob@BruteSpeed

iTrader: (16)

Sounds like a good plan. Bob