I'm considering 4.10's for my MT82 car

[skaarlaj]

Hey guys, I have a 2012 MT82 base GT. So far my only mods are my M&H 28" tall drag radials on the stock wheels that I received for x-mas, and MBRT Mufflers that were on it when I picked it up used.

My goals are a good daily that will show well in a drag race. I know a lot of people like their 3.73's with their track pack manual cars, but I'm going to be down on power here at 6500' elevation here in Wyoming, and will not be turning quite 2600rpms with 4.10's on a 28" tall tire, so I'm not a bit uncomfortable with that rpm on the highway.

So, does anyone have 4.10's with an mt82 trans that is disappointed with their choice? Otherwise, It's likely going to be what I end up going with. I know this might need re-addressed if/when I ever get away from being N/A, but for me, I think it will work great for now.

Also, if I do swap gears without a "ecu" change/calibration, the only thing that will be effected will be my speedometer will show faster than actual, correct?

 

[Mystickeith50]

I couldn't even imagine going higher than 3.73.

 

[JeremyH]

No personal experience with it personally for that trans, but everyone I have seen that gears up ends up running slower and going back to factory gears.

 

[Speedboosted]

Too much gear, you'll be shifting so often you'll go slower like Jeremy mentioned. There is a guy that has 4.10s that goes to the local events around here and he's always the slowest 5.0 there. He's not even a bad driver or anything

 

[Five Oh Brian]

For a daily driver that sees some drag duty, that has 28" tall drag radials, 3.73's will be best with the MT-82. My '11 GT MT-82 came with 3.73's, but I put 4.56's in. No improvement in the 1/4 mile. Both gearsets allow going through the traps in the 1/4 mile at the top of a gear (4th for 3.73's, 5th for 4.56's), but the 4.56's force a tough shift into 5th gear. Any gear in between (3.90's, 4.10's, or 4.30's), put you in the wrong rpm's on a 28" tall tire going through the traps. On the flipside, though, I actually liked having the extra gearing for street use. 4.10's and up are entertaining to drive, but not everyone likes that much gears.

 

[cbass]

I seriously considered 4.10's until I drove one with 4.10's. First was a rock crawling gear, second felt like first coming from my 3.31 car. If you want to have a dumb car that does burnouts all the time, that's the gear for you. But if you want to go faster at the strip, stay in the 3's.

 

[usafimj]

I read somewhere that 3.73s in a 2011+ 5.0 is similar to 4.10s in a 05-10 GT. Not sure how true that is.

 

[skaarlaj]

I'll actually be able to go 2mph faster in 1st with this 2012 on a 28" tall tire than my fox with a t5 on a 26" tire with 4.10 gears as with this 2012 5.0 with the same gears. I love the way the fox launches and this 2012 is heavier and less powerful, but revs out another 500rpms comparably, just seems weird not to go with steeper than 3.73 gears, especially givin that my fox feels more torqey down low, and the coyote seems kind of doggy until revved.

In one of these cars with an auto, and the ultra low 4.17 1st gear, I can easily see not wanting to go into the 4.10 range, especially when you can go up against a loose converter instead of a clutch. Not arguing here, just trying to make sense on the subject.

BY estimating my trap speeds of about 88 in the eighth, and 110-113ish in the quarter with the coyote, The gear calculator definitely says the 3.73's will keep me from going into 4th in the eighth, and 5th in the quarter with 3.73's, so I would more than likely be performing 1 less shift in either race. I guess I just have to hope like hell it will launch stronger than I can imagine it would with 3.73 gears because powershifting this car is the easiest thing since sliced bread compared to any other manual I've ever owned, so the shifting doesn't bother me a bit, thankfully

I couldn't even imagine going higher than 3.73.

I couldn't imagine anything less than 3.73's, even though 1st is nice and fairly steep, a 28" tall rear tire definitely makes it a bit less extreme.

I seriously considered 4.10's until I drove one with 4.10's. First was a rock crawling gear, second felt like first coming from my 3.31 car. If you want to have a dumb car that does burnouts all the time, that's the gear for you. But if you want to go faster at the strip, stay in the 3's.

At 7K with a 28" tall tire and 4.10's I'd be at 39mph at red-line, 42 with 3.73's, and 48 currently with the stock 3.31's.

For a daily driver that sees some drag duty, that has 28" tall drag radials, 3.73's will be best with the MT-82. My '11 GT MT-82 came with 3.73's, but I put 4.56's in. No improvement in the 1/4 mile. Both gearsets allow going through the traps in the 1/4 mile at the top of a gear (4th for 3.73's, 5th for 4.56's), but the 4.56's force a tough shift into 5th gear. Any gear in between (3.90's, 4.10's, or 4.30's), put you in the wrong rpm's on a 28" tall tire going through the traps. On the flipside, though, I actually liked having the extra gearing for street use. 4.10's and up are entertaining to drive, but not everyone likes that much gears.

Even with your much steeper 1st gear with your stalled auto, I wouldn't say 4.10's are slowing you down, maybe not more beneficial than a 3.73, or 3.55, but it's not hurting you if you're not struggling with traction imo. I think it's impressive to see a NA full weight car like yours without even as much as a cai that runs solid 11's, just sayin.

I read somewhere that 3.73s in a 2011+ 5.0 is similar to 4.10s in a 05-10 GT. Not sure how true that is.

Probably is the case, these transmissions do have a very low 1st gear compared to nearly any other common older stang transmission. I had 4.10's in my old 04 cobra with a t56 with a 2.66 1st, and I wished I would've done 4.30's on that one.

 

[Five Oh Brian]

You are certainly right that an S197 5.0L weighs a lot more than a Fox Body, and gearing can really help get that mass moving easier from a standing start. I really enjoy more gear than most people do, so I don't want to talk you out of more gear in the '12 5.0L. However, more than a 3.73 gear with a 28" tall tire will force a shift into 5th gear in the 1/4 mile. You'll launch better, but any improvement in your short times will be negated by the extra shift into 5th. That's what I saw with my '11 GT MT-82 going from 3.73's to 4.56's; much better launch, 60', 330', and 1/8, but no better 1000' and 1/4. My '14 GT auto improved slightly going from 3.15's to 4.10's, but the extra shift in a tuned/stalled automatic takes mere milliseconds so the extra shift in an auto doesn't matter.

As a daily driver, sounds like you'll really love the 4.10's with the 5.0L / MT-82 based on what you've been saying, so give it a shot. Likely won't be quicker in the 1/4 mile, but you may like it better none-the-less. Just like some people like louder exhaust and/or CAI's, even if when they don't make a car faster.

 

[46Tbird]

As a daily driver, sounds like you'll really love the 4.10's with the 5.0L / MT-82 based on what you've been saying, so give it a shot. Likely won't be quicker in the 1/4 mile, but you may like it better none-the-less. Just like some people like louder exhaust and/or CAI's, even if when they don't make a car faster.

Completely agree with this point. For some people, it is fun to shred through the gears.

My stock un-tuned coyote crosses the eighth at the very top of third, and crosses the quarter at the very top of fourth. That is with a stock rev limiter, 3.73s, and a 28.5" tall 305/35-20.

Your ET will benefit with the 4.10s only if you have a tune and some parts (intake, exhaust) that will let you take it out to 7500+ RPM and make some power there. Otherwise the extra shift will hurt your ET.

 

[skaarlaj]

Yeah, so its sort of a decision to either better 60's with a 4.10, or one less shift in either the eighth or quarter with 3.73's. I'd actually like to give 3.90's a try, but ford racing doesn't offer a set in that ratio. I used a ford racing set in my fox, and Richmond in my 04 Cobra, and I had to re-shim the Richmond pinion 3 times before the pattern looked good, the ford racing took the shim off the old stock pinion and was spot on the first time.

 

[rcm90]

You need to find out what the car traps at the elevation its in and go from there.

FWIW my car n/a went 11.68@115 in elevation where it should have went very high 10's to low 11's@122-123 at sea level. Since the car is much further down on power and cannot accelerate its self into the power band, it would benefit from more gear so it crosses at the proper rpm in third or fourth depending on the transmission.

 

[skaarlaj]

You need to find out what the car traps at the elevation its in and go from there.

FWIW my car n/a went 11.68@115 in elevation where it should have went very high 10's to low 11's@122-123 at sea level. Since the car is much further down on power and cannot accelerate its self into the power band, it would benefit from more gear so it crosses at the proper rpm in third or fourth depending on the transmission.

I've done some tests with my G-tech pro, and it has said about 88 in the eighth, and 111-114 in the quarter. It's been pretty accurate and repeatable in the past. So 3.90 gears would be almost maxxed out rpm's in both races, and 4.10's would surely mandate an extra shift in each race as well according to my favorite on-line calculator. These are using the ratios of an mt82 trans on a 28" tall tire.

 

[skaarlaj]

Well, for those interested I ordered a set of motive 3.90 gears that should be here today. I'll hopefully have them in sooner than later, and I'll surely report back on how she feels. I don't have any "before" track times, but I have 2 recorded runs on my g-tech pro. Here's the 2 runs below.

1/8th=8.5@88 with a 2.1 60' same run 1/4 was 13.0@111

1/8th=8.4@90 with a 2.0 60' same run 1/4 was 12.7@113

These times where with my 28" M@H drag radials @20psi, stock clutch, stock gears bogging pretty bad w/o tire spin on an asphault highway in 23* weather at 6700ft elevation.

 

[obsrt86]

I read somewhere that 3.73s in a 2011+ 5.0 is similar to 4.10s in a 05-10 GT. Not sure how true that is.

Yes! I was actually thinking of this when I drove my buddies '14 w/3.73. It felt very similar to my car w/4.10s. Huge difference compared to my other buddy's '14 w/stock 3.31. In my opinion, 3.73 is the perfect gear for the coyotes w/mt82