kidnizmo

Hey i have a 08 GT auto, does any have a auto GT with 4.10s and what are you driving impressions or opinions? Reason for post is because i called Roush about gears and they strongly suggest 4.10 instead of 3.73 gears for my auto. I went to a local mustang performance shop and they said 4.10s also. So i called Evolution and Fred said dont even waste my time on 3.73s, because he had 4.30 in his car but 4.10 are much more suitable for DD. go figure

so again, any driving impressions from 4.10 automatic GT?

Atlanta_Tider

One of my friends who posts on here, he had 4:10's in his car for a short while and backed down to 3:73's. He does have a long commute everyday but enjoys the 3:73's much better for all around driving. I am totally happy with my choice of 3:73's.

2cokeman

4.10 AUTO= NO TRACTION!! No first gear!! Maybe ok on slicks at the track, city driving forget it!

Hootna

No complaints. Did have issues getting the power to the ground at first but now with all the mods it hooks up no problem. The best bet is 3.73s though...

07BLACKGT

Does anyone have any videos of normal driving with 4.10's in an auto?

I've been swaying back and forth on 3.73's and 4.10's for 6 months now.
...I'm not sure if I'll ever make up my mind.

FloridaGT/CS

I ran 3.73 for about 6 months, and I believe it is the best "all-around" gear for the automatic, but I've had 4.10 gears for over 4 months now and really enjoy them more. 4.10s are NOT too much gear for a naturally aspirated engine UNLESS you do a lot of hiway driving... or more than an hour at 70mph each day (IMHO). The engine rpms will be slightly higher, however at the legal speed limits the car hiway performance is fine (with the exception of slightly LOWER gas mileage). I run 285 Eagle F1s on the rear, and traction is about the same as running 255 BFGs with 3.73s (with suspension upgrades, lowers, uppers and anti-squats). Sorry to drag the reply out, but I'd simply say go 4.10s if you do 90% city driving and are NOT going FI in the future... and go 3.73s in all other situations. Hope that helps!

howarmat

These are the internal gearing numbers for the trannys. Since the auto and manual transmission have different internal gearing, the rpms and such are different in different gears.

Automatic transmission gearing
1st: 3.22 .1
2nd: 2.29 .1
3rd: 1.55 .1
4th: 1.00 .1
5th: 0.71 .1
Rev: 3.07 .1

Manual Transmission gearing
1st: 3.38 :1
2nd: 2.00 :1
3rd: 1.32 :1
4th: 1.00 :1
5th: 0.675 :1
Rev: 3.38 :1

The final drive gear is calculated by using the tranny ratio times the rear end ratio

So in 5th gear you would have
M: 4.10*.675= 2.76
A: 4.10*.71=2.91
A: 3.73*.71=2.64

Ideally a 3.90 gear set in the auto would equal the 4.10s in a manual but they are NOT a FRPP gear so that is one reason most people do not use them.

Notice other gears besides the final gear too......some of those numbers are much different in the auto than the manual. Its really personal preference but usually you are stepping up from 3.31s in the auto and going up to the 3.73s will give you a nice kick in the pants and the RPMs on the highway are not terribly high this way.

stealth_GT

for anyone that thinks about getting 4.10s or not, I think they should get them installed and see how they like it, if not they can just install 3.73s. I heard it's break neck acceleration from a dead stop. Seen a few vids and they all launch like a bat outta hell!~

To me, it sounds like a type of mod where you have to experience it for your self and see if you can live with the 'price vs acceleration' reward.

Gonna install mine in March when the snow clears up.

howarmat

with the gear install cost being 300-500 and parts being 200, people are going to "test" out the setup. They will get a set installed and then deal with it regardless of the outcome

stealth_GT

(^_^)

lol that's what I meant... I really do think that most people would appreciate the 4.10s in the auto.