MUSTANGGT06

I just read an old article by "Alternative Auto Performance" out of Michigan who specializes in Mustang performance upgrades and they said that the 05 and up Mustangs with the 5-speed automatic transmissions would not benifit with 4.10's gears. The article said that the low 3.22 ratio first in the new GT makes good use of 3.30 ratio in the 8.8 rear axle and 4.10's would be way to steep if stock or near stock tire height is retained. The 4.10's would make the engine run out of, or accelerate out of its torque too quickly in first gear. They suggested to stay with 3.31 and go with a looser converter. I have installed 4.10's and have not noticed any increases in my ET at the track, but again I don't run it alot at the track and still have alot of practice to do. Does anyone have there oipion on the above and maybe this is the reason for no better ET times. Also, anyone with an GT auto who has switched to 4.10's, how much have you seen in ET improvement times.

Derf00

Based on what I know about the New Edge 4 Spd auto and the newer 5 spd auto in our S197 GT's I'd agree with that shop. The S197 Auto tranny has an already steep 1st gear and while 4.10 were the gear of choice in the older 4spd, I think it's a mistake on the newer 5 spd.
3.73 is what I plan on going with.

I'm not sure what the shop means by a "looser" converter (higher stall converter maybe?)

I don't have any track experience so I can't speak about any differences in ET's or Top Speed.

stealth_GT

I think the gears are fine, the car just need suspension mods and better tires. They are just really aggressive off the line, but they're fine IMO...

Budman2K

I had 4.30's installed in mine, and couldn't be happier. I drive it daily with a b@m@ 93 race tune installed and have no regrets.

08GT4U

i nocked off 2 tenth of the 1/8 by switching to 4.10s.

Derf00

knocked 2/10ths off by switching to 4.10s from what?

Mishri

I went (intake+tune) 14.6@98mph then with gears, cmdps and under drive pulleys I went 13.5@102mph

I didn't gain 1.1 off those 3 mods though, DA corrected I ran 13.3@106mph and 12.8@108mph so i gained .5 and i think atleast .3 or .4 of that is from the 4.10s over the 3.31s and im still using stock 17" rims on stock tires.

overall.. that article is BS.. im not even close to running out of gear in 4th.. although that coudl be because im only oging 102mph at this elevation.

stealth_GT

.. the only time I run out of gear is with the O/D off on the freeway topping out at 135, needle @ 6100 RPM.

Not sure if it's the tune or tires, but it's pretty guey.

But it tops out 145 easy with the O/D on...

One Bad Stang

i dont have an auto, but i can definatly say the 4.10's make the car faster. (at least with manual trans) i havent been to the track yet to prove it, but it's really noticeable.

howarmat

3.73 for auto, 4.10s for manual. I would agree with the shop. If you look at each gear and compare 3.73 Auto vs 4.10 man they are close. With 4.10s in the auto each gear is pretty short, some people like it but 3.73 seem to be the best fit all around.