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How are people liking 4.09 gears in the MT82?

Sik19GT

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Sorry to bump an old thread but, I just installed 4.09s on my car because of this thread. After finally getting a nice long drive in with the gears installed. I can say these cars should have came with 4.09s from the factory. The cars rips through the gears now, and it still only revs to 2750 at 90mph in 6th. These are a must have for anyone with a NA engine and the mt82D4!
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Ordered mine today, Ford performance states the pcm will need flashed and I will. The speedometer is not the only thing the pcm uses the ratio for. It use it to calculate load on the engine. So under acceleration if the pcm thinks you have 355 installed instead of 409 then it's going to calculate a higher load and reduce timing accordingly. As a retired ase master auto tech I know better than to listen to the internet techs that don't have certifications and real world experience. You also risk a cel as the pcm will see the rpm out of spec for the gear indicated.
 

Sik19GT

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Ordered mine today, Ford performance states the pcm will need flashed and I will. The speedometer is not the only thing the pcm uses the ratio for. It use it to calculate load on the engine. So under acceleration if the pcm thinks you have 355 installed instead of 409 then it's going to calculate a higher load and reduce timing accordingly. As a retired ase master auto tech I know better than to listen to the internet techs that don't have certifications and real world experience. You also risk a cel as the pcm will see the rpm out of spec for the gear indicated.
You will need a tune for sure. And if you have a performance pack a custom tune. I tried to just flash my car for the different gear with my SCT. But it threw a bcm code. Due to the auto rev match, the car was not happy with the gears. I had to email my tuner and get a custom tune to fix the issue.
 

Mikepol2

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Sorry to bump an old thread but, I just installed 4.09s on my car because of this thread. After finally getting a nice long drive in with the gears installed. I can say these cars should have came with 4.09s from the factory. The cars rips through the gears now, and it still only revs to 2750 at 90mph in 6th. These are a must have for anyone with a NA engine and the mt82D4!
Congrats! Next time you drive one with 3.73’s you’ll be amazed how much slower it feels!
 

MRGTX

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Sorry to bump an old thread but, I just installed 4.09s on my car because of this thread. After finally getting a nice long drive in with the gears installed. I can say these cars should have came with 4.09s from the factory. The cars rips through the gears now, and it still only revs to 2750 at 90mph in 6th. These are a must have for anyone with a NA engine and the mt82D4!
Sorry to bump the thread? I’m subscribed to this thread for exactly this kind of feedback. :)
That sounds awesome...I’m. very glad to hear that the new ring and pinion made such a big difference.

I just got back from a joyride, dismayed as I arrive at the conclusion after 1500 miles that my sorely missed 2011 GT 6 spd (with just 3.55s and a tune) would walk my 2020 base GT 6spd all day long.

I have my 4.09 kit sitting in the box, waiting for my first oil change...none of the local shops want the work of setting up the gears so I guess Ford Dealership will have to do it.

Did you do the work yourself? If not, do you mind saying how much you paid?
 

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Mikepol2

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Sorry to bump the thread? I’m subscribed to this thread for exactly this kind of feedback. :)
That sounds awesome...I’m. very glad to hear that the new ring and pinion made such a big difference.

I just got back from a joyride, dismayed as I arrive at the conclusion after 1500 miles that my sorely missed 2011 GT 6 spd (with just 3.55s and a tune) would walk my 2020 base GT 6spd all day long.

I have my 4.09 kit sitting in the box, waiting for my first oil change...none of the local shops want the work of setting up the gears so I guess Ford Dealership will have to do it.

Did you do the work yourself? If not, do you mind saying how much you paid?
Lots of posts on that in other threads but most of the labor is in removing the diff. I gave a guy the diff, gears and $200 and he installed them for me. His wife is a Ford service writer and says dealerships will charge for about 12 hrs of labor, and 8 is removing and reinstalling the diff.
 

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Yikes...so it sounds like it would make sense to swap to the torsen at the same time if it’s ever going to be on the menu. Ugh...I think we call this “mission creep.”
 

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Yikes...so it sounds like it would make sense to swap to the torsen at the same time if it’s ever going to be on the menu. Ugh...I think we call this “mission creep.”
Do it and don’t think twice. No regrets.
 

MRGTX

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Do it and don’t think twice. No regrets.
Well, sure but it tacks another $700 or so onto a $1500 (give or take) job for parts and labor. I’m not broke but that’s a fair chunk of money in my world.

I still don’t have a good sense as to when the torsen proves itself to be that much better. I gather that cars that get tracked wear out the clutches in the track lock style rear relatively quickly...but does the torsen perform that much better?

I opted for a Torsen style limited slip for my Mopar project and so far, aside from requiring expensive oil ($65/gallon or so? ) it hasn’t felt any different from the old fashioned Mopar Sure Grip after a few thousand miles hooning around the back roads.
 

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My feeling on the Torsen is that it almost feels like 4 wheel steering when you’re going around bends. It feels like the back of the car is rotating itself around for you. Not saying its necessary or not, just saying if you want to add it, doing it at the same time as the gear change makes sense.

As far as the cost goes, there are ways to cut it down. I waited and looked frequently on Ebay and got the gears and install kit for about $225 total. Shopped around and networked to find the guy to do the gear install. And did the diff removal and reinstallation myself with the car on jack stands. Started with Torsen and 3.73’s so my total cost was around $500.
 

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Alright. I ordered the Torsen unit.

It looks like new Track Lock units for for $200 or so. Perhaps I can recoup $100 on my current one with less than 2k miles on it. I’ll post it up in the classifieds when I’m ready to go.
 

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I'm still watching with interest too ...

I've committed on 4.09 with Torsen (converting from a 3.55 tracloc).

It will be a long time before mine is installed though - my cars still on the production line ...

WD :like:
 

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Did you do the work yourself? If not, do you mind saying how much you paid?
I pulled the diff myself and had a local shop set up my gears (papinis garage in Temecula ca) they installed the gears for 250. Which I felt was totally worth it because I do not wanna deal with howling gears or a noise rear diff.

I seriously feel like these cars should come with these from the factory. The 4.09s with the torsen diff make for a hell of a back road monster.
 

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I'm still watching with interest too ...

I've committed on 4.09 with Torsen (converting from a 3.55 tracloc).

It will be a long time before mine is installed though - my cars still on the production line ...

WD :like:
Have you considered switching to a performance pack car? It may not be too late. You may have your reasons for wanting your specific configuration but I went into this looking for a fun daily driver and started feeling like the stuff missing from the base model would bug me. In addition to the torsen, there's a ton of little things that will be annoying/expensive to do on your own.

I've already bought the PP Brembos, all of the PP chassis bracing, the PP front lip and undertray...now I have the 4.09 ring and pinion and torsen to install. Yeah, my car was cheap but with the 0% financing, it didn't need to be quite THIS cheap. My regrets are minor. I'm happy with the car and the little projects have helped make it feel like "mine" but it would have made a lot more sense to buy a PP car to begin with. I also would have gotten the cool gauges, etc.

I pulled the diff myself and had a local shop set up my gears (papinis garage in Temecula ca) they installed the gears for 250. Which I felt was totally worth it because I do not wanna deal with howling gears or a noise rear diff.

I seriously feel like these cars should come with these from the factory. The 4.09s with the torsen diff make for a hell of a back road monster.
This is super encouraging and I am tempted to try this myself.Iwill have to admit some fear in disassembling my brand new daily driver car that I rely on.
 

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Have you considered switching to a performance pack car? It may not be too late. You may have your reasons for wanting your specific configuration but I went into this looking for a fun daily driver and started feeling like the stuff missing from the base model would bug me. In addition to the torsen, there's a ton of little things that will be annoying/expensive to do on your own.

I've already bought the PP Brembos, all of the PP chassis bracing, the PP front lip and undertray...now I have the 4.09 ring and pinion and torsen to install. Yeah, my car was cheap but with the 0% financing, it didn't need to be quite THIS cheap. My regrets are minor. I'm happy with the car and the little projects have helped make it feel like "mine" but it would have made a lot more sense to buy a PP car to begin with. I also would have gotten the cool gauges, etc.


This is super encouraging and I am tempted to try this myself.Iwill have to admit some fear in disassembling my brand new daily driver car that I rely on.
I am UK based so our cars are a mixture of PP1 and a premium :like:

We get little option to switch things like the diff and it’s one thing they dropped from the PP package - every UK GT (or Bullitt) gets a 3.55 tracloc.

We get the K brace but the strut brace is also missing - something to do with crowd eater impact regs.

WD :like:
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