This question is geared more towards the turbo crowd.

how many of you are running a 3.15 rear and are happy with it?

I have a good source for a solid 3.15 to replace my 3.38. should I go with it or go straight for a 2.91? Cost is an issue here since I am hesitant to blow another grand on a diff at this very moment.

thanks,
Ron

Personally I would go with the 3.15 diff. If price is a concern, it would be logical to save the 7-900 and give the 3.15 a shot. If you buy the diff used, there's a good chance that you'll be able to recoup a large majority of it if you do decide to sell it later on and upgrade to a 2.93.

Just my .02

Im still running the 3.15 diff....It makes for a difficult launch in first gear and still blows the tires in 2nd (255 40 17's). I do like the acceleration in 5th gear.
70-80 in < 3seconds. but Im considering going to a taller gear ratio.

thanks for the replies fellas.

bassmaster - is this a joke? Est..1001 rwhp!

2.79

It depends on how much power you plan on running and how responsive your turbo is. I ran a 3.15 with my 6 speed when I had my AA Stage 3 kit with 60-1/TD06 and it seemed to be a pretty nice match for my driving style. If I had a 5 speed I would have considered the 2.93 though because you don't have that nice tall overdrive gear to load the turbo on the highway.
When I went to a T61 turbo, I had a 2.93 installed from DiffsOnline. This diff was definately required as the T61 makes boost much higher up in the rpm range and needs the taller gearing to take advantage of the power (530+ rwhp). A 2.79 might have been a better choice for the way this turbo behaves, which is more like an On/Off switch.
I am now going with a GT35R which will make the same power but be significantly more responsive than the outdated T61, and I think the 2.93 will be a perfect match to it with the 6 speed.




This question is geared more towards the turbo crowd.

how many of you are running a 3.15 rear and are happy with it?

I have a good source for a solid 3.15 to replace my 3.38. should I go with it or go straight for a 2.91? Cost is an issue here since I am hesitant to blow another grand on a diff at this very moment.

thanks,
Ron

Josh,

thanks for the informative post.

if it helps to know, the setup would be a T3/T4 boosting a max of about 8psi.

the car will remain my daily beater and I'd like to keep around town driving as unhindered as possible.

Josh,

thanks for the informative post.

if it helps to know, the setup would be a T3/T4 boosting a max of about 8psi.

the car will remain my daily beater and I'd like to keep around town driving as unhindered as possible.

With that setup I suggest staying with a 3.23 or 3.15. With those ratios I think you are good to about 350rwhp.

You might be alright with the 3.15 as it sounds like you are going to be in the 300 rwhp range. My first turbo setup was an AA OBD2 stage 1 kit in that power range and I ran a 3.23. It was a little bit too short, but I think a 3.15 would have matched up with it pretty well.

i have the stock 3.43 on my 535 turbo, works well although some have recommended that i go with a 3.15 in the future. my turbo is a to4e 60 if that makes any difference.

cool, so from this consensus, the 3.15 should be a pretty good start.

thanks fellas.

thanks for the replies fellas.

bassmaster - is this a joke?

Of course its a joke...I dont have 1/2 that amt of HP :)

It depends on how much power you plan on running and how responsive your turbo is. I ran a 3.15 with my 6 speed when I had my AA Stage 3 kit with 60-1/TD06 and it seemed to be a pretty nice match for my driving style. If I had a 5 speed I would have considered the 2.93 though because you don't have that nice tall overdrive gear to load the turbo on the highway.
When I went to a T61 turbo, I had a 2.93 installed from DiffsOnline. This diff was definately required as the T61 makes boost much higher up in the rpm range and needs the taller gearing to take advantage of the power (530+ rwhp). A 2.79 might have been a better choice for the way this turbo behaves, which is more like an On/Off switch.
I am now going with a GT35R which will make the same power but be significantly more responsive than the outdated T61, and I think the 2.93 will be a perfect match to it with the 6 speed.


I have the same set-up 2.93 w/6speed should be perfect.