lexxs

iTrader: (8)

Hello I got a quick question about the differential i’m about to purchase over sea .The seller say is 43.11 gear ratio can i use this differential for my manual transmission?

DaleClark

iTrader: (55)

You have your gear ratio wrong.

Stock the manual trans cars had a 4:11 gear ratio, automatic cars had a 3:90.

There were a few special models that had a 4:30 gear ratio.

Dale

boostin13b

All of the RZ models had 4.30 IIRC and I believe the RS models from 96 and up did as well.

lexxs

iTrader: (8)

the ring gear had 43 teeth and the pinion gear got 11 I use 43 divided 11 it came out 3:90 the differential that i’m about to buy it’s from an automatic . Is this right?

j9fd3s

iTrader: (3)

yep, 43:11 is the 3.9, which is for the A/T cars

TeamRX8

iTrader: (2)

did the auto trans diff have a limited slip?

billyboy

No, a torsen!

lexxs

iTrader: (8)

So can i use AT differential 3.90 gear on a manual transmission? What kind of affect will it be 4.10 to 3.90 gear ratio?

tomsn16

iTrader: (283)

Auto 3.9 diff companion flange has different bolt pattern and will not fit manual drive shaft.
Also 3.9 will decrease acceleration....most folks prefer going other direction on final drive ratio ( either 4.3 or 4.4).

cewrx7r1

iTrader: (2)

If you you are making over 400whp, with non drag tires, the 3.909 would be better with the short Japanese 5th gear.
I run the 3.909 diff with the short 5th gear.
At 7500 RPM WITH .719 5TH GEAR AND 225/50-16 TIRES STOCK SETUP
DIFF 1st 2nd 3rd 4th 5th

4.10 37 65 94 131 182 24.3 mph per 1K rpm

3.909 39 68 99 137 191 25.5 mph per 1K rpm

At 7500 RPM WITH .806 5TH GEAR AND 285/35-18 TIRES
DIFF 1st 2nd 3rd 4th 5th

4.10 38 66 95 132 164 22.0 mph per 1K rpm

3.909 40 69 100 139 172 23 mph per 1K rpm

ptrhahn

iTrader: (9)

Yeah, when your power level is such that you're just spinning the tires above 5k in gears 1-2, I'm not sure harming the acceleration matters.