Gear time

[ViciousJay]

Ok, a buddy of mine and i have been saying were both gonna do a gear to our cars. He's going 4.10 with his 2007 mustang. Lately he's trying to get me to do the same but im not a huge drag racer and maybe see the track a handfull of times a year. I have a premium car but im not sure on my current gear size, I was kicking around 3.55 or 3.73

which should i do? i dont want a to kill my gas mileage. also will i need it tuned to compensate for the smaller gear

 

[203Cree]

3.73's are a good compromise. You don't completely kill the mileage and you still get good acceleration out of them. And you'll need to adjust the speedo at least. More if you're running an auto.

 

[SID297]

I like 3.73s but the 5.0 loves 4.10s.

 

[ViciousJay]

see the only reason im even considering 3.55's is because this car is close to being geared as a cobra

 

[steedafever]

I'm in same boat deciding. Not so sure about 4:10s bc I may road course the car

 

[ViciousJay]

I'm in same boat deciding. Not so sure about 4:10s bc I may road course the car

also i dont want to be at 2800@80mph

 

[cobra199711]

BEWARE- I had my gears swapped and the whine is terrible! I went from 3.31s to 3.73s and WISH id didnt. The shop is reputable and even redid them for back lash and they still whine. They were brand new Ford gears to boot. Just be careful!

 

[ViciousJay]

BEWARE- I had my gears swapped and the whine is terrible! I went from 3.31s to 3.73s and WISH id didnt. The shop is reputable and even redid them for back lash and they still whine. They were brand new Ford gears to boot. Just be careful!

did they shim correctly? the person that would do my install does this day in and day out for a living on big rigs, cars, trucks... etc...

 

[cobra199711]

I would assume they did, this was a Mustang shop etc... Can I be for certain nah- but I believe them. Heck he even offered to put my stock gears back in for free. Hopefully other people have better luck (but have heard this story numerous times). I guess Ill buy a louder exhaust to drown out the whine : )

 

[Sir Nate 3000]

BEWARE- I had my gears swapped and the whine is terrible! I went from 3.31s to 3.73s and WISH id didnt. The shop is reputable and even redid them for back lash and they still whine. They were brand new Ford gears to boot. Just be careful!

I'm thinking it's the install. I had frpp 4:30s installed in my 5sp 2004 Mach1 and I had no whine, ....I also had no 1st gear

 

[chrisheltra]

Love my stock 3.73's

 

[mixxer]

3.73

 

[stang1971]

i have 4.10's in my auto and love them. ZERO whine...

 

[Grant808]

with stock 3.73s I can get the advertised 26 hwy and 15-16 city...If I'm driving 'normally'. Don't worry about the gear and milage...most of that depends on how you drive.

 

[Sir Nate 3000]

what about 3.90s?

 

[grnenvy]

3:55s all day long! If you add any more pwr or go with a power adder you will be over geared! Then you will have to run a 28in tall tire to fix it! The 3:55s made a nice diff in my car and it's even faster for highway pulls. There's no way my car would be as fast on the highway with 4:10s and down here in FL everyone cruises at 80mph.
'My next move may be a Precision Industries 9.5 converter once it's avaliable and with any more gear it would be usless on the street and thats where most of us spend most of our time!
Now if you looking for every little bit and your going to run the big tire and do the suspenion for traction then that may be a diff story!

You guys need to remember this isn't the old school trans with the 2.40 first gear it's much lower!!!

 

[Grant808]

3:55s all day long! If you add any more pwr or go with a power adder you will be over geared! Then you will have to run a 28in tall tire to fix it! The 3:55s made a nice diff in my car and it's even faster for highway pulls. There's no way my car would be as fast on the highway with 4:10s and down here in FL everyone cruises at 80mph.
'My next move may be a Precision Industries 9.5 converter once it's avaliable and with any more gear it would be usless on the street and thats where most of us spend most of our time!
Now if you looking for every little bit and your going to run the big tire and do the suspenion for traction then that may be a diff story!

You guys need to remember this isn't the old school trans with the 2.40 first gear it's much lower!!!

Good advice for an automatic...I think the manuals tolerate much steeper at the rear. With the 4.17:1 1st in the auto, I think even the 3.31 should be enough for most.

 

[28]

what about 3.90s?

That's what I've been waiting to see results on..:rockon::burnout::beer:

 

[1Sick2Valve]

I can't remember is your car an auto? If its an M6 4.30s!!

 

[5.0jake]

I originally had 3.31's and really disliked them(boring/unsatisfying), so I had 3.73's installed at the dealer.
Car feels much more responsive and urgent in every gear and is much more fun to drive overall. I could imagine the 4.10's being even more fun but my daily commute has a lot of nasty traffic.
I overall average 1mpg less than the 3.31's but well worth the trade off.
Skip shift hardly ever engages now
No whine except I do have a noticeable whine/or hum in 6th gear only now but it's not intrusive.
Very happy overall.