3.73 or 4.10?

[BlackGT01]

Just bought a 2008 GT with an auto after being out of the mustang market for the last 6 years. I am happy to be back. This car will be a sunny day car and spend it's weekends at the track. What are you running for gears in your auto's? Am I going to see a big difference at the strip between 3.73's and 4.10's. I am not worried about fuel economy. That being said, I don't want anything bigger than 4.10's. Are they good for a tenth or two?
What should I expect to run with this car? My 01 ran 13.7's stock with a set of slicks.
Thanks
Fred

I love these cars. Pictures to come shortly.

 

[stangzilla100]

the 2008 autos come w/ a 3.31, i think. go w/ the 4.10's if youre going to race it at the track and not a DD.

 

[whyask]

ive run 3:73s, 3:90s, and 4:10's in my auto with a stock converter and I love my 4:10s !! Its my DD and track day car as well !

 

[bigcat]

go 4.10s, or dont do it at all. you are just going to wonder why you didnt do it right the first time. I have 4.30s in my manual trans and would not have it any other way!

 

[whyask]

What he said

 

[klaw]

go 4.10s, or dont do it at all. you are just going to wonder why you didnt do it right the first time. I have 4.30s in my manual trans and would not have it any other way!

Are 4.10's too much for F/I? I have a Whipple at 10 psi and bought 3.73's this past weekend. My '07 GT 5-spd came with 3.31's.

 

[bradleyem]

go 4.10s, or dont do it at all. you are just going to wonder why you didnt do it right the first time. I have 4.30s in my manual trans and would not have it any other way!

So, 4.30s work out pretty well with the 5 speed? I've been trying to decide myself, and I agree that I should do the tallest gears that I can deal with for a d/d. If I ever do a 6 speed swap, that would be the icing on the cake

 

[stangzilla100]

Are 4.10's too much for F/I? I have a Whipple at 10 psi and bought 3.73's this past weekend. My '07 GT 5-spd came with 3.31's.

i have the HO and 4.10's and it can loose traction quite easily on street tires, have not tried w/ DR's or slicks. you'll be fine w/ the 3.73's

 

[BlackGT01]

Thanks for all of the advice. I am going to indeed go with the 4.10's. Looking forward to the spring to be able to ride again.

 

[klaw]

i have the HO and 4.10's and it can loose traction quite easily on street tires, have not tried w/ DR's or slicks. you'll be fine w/ the 3.73's

Thanks! Will be installing the 3.73's over the next while. I'll let you know how they work out!

 

[bigcat]

So, 4.30s work out pretty well with the 5 speed? I've been trying to decide myself, and I agree that I should do the tallest gears that I can deal with for a d/d. If I ever do a 6 speed swap, that would be the icing on the cake

i have not had any complaints with with the 4.30s. just dont plan on long roads trips all the time unless you can live with the increased RPMS for the entire trip. some whine that its too high, but around 3000 RPM is not too much for me.

 

[StonePony]

3.73 is the best all around gear for the automatic, especially with forced induction. You will reatain some highway performance with them and have better gas milage and still increase your acceleration over the 3.31 gears.
If you drag race you should determine with your setup if you still want to be in 4th gear when you go through the traps, because depending on tire diameter you could be forced to shift in to 5th before the end of the 1/4 and that is not optimal.

 

[Five Oh Brian]

Supercharged automatic GT here. 4.10's and wouldn't have it any other way with the S197 automatic. 4.30's in a manual trans car work great with the deeper overdrive ratio (.68), but 4.10's is pushing it for automatic's overdrive (.71).

I do need taller drag radials, though, as I'm in 5th gear about 200 feet before the end of the 1/4 mile with short 275/40/17 BFG drag radials, yet still turning 12.30's @ 111+.

Way back before the supercharger, when it was just 4.10's, tune & drag radials, my 07 GT automatic was running 13.40's @ 102+. Added a big stall converter and went 13.20's. That was with 100% stock engine, exhaust, and suspension, too!