2019-up 4.09 Rear Gear Swap

[Dave2013M3]

That sucks. One of the main reasons I have hesitated on the gear swap is I have only found one shop that I feel comfortable doing the work, but they are 2 hours away. The delay in doing it though, made my mind wander to other mods or swapping cars. Still may do it... I am curious to know how you like them once you get it sorted out.

This shop came highly recommended for gear swaps. The tech send me all the pics showing me the backlash, the gear pattern. The simplest part of the job, the ProCal setting to 4.09 and they screw the pooch.

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[Dave2013M3]

Car is up and running, fixed the bricked ECU I will give my feeling on the swap later as I really haven't had a chance to drive the car much. So far the impressions are highly favorable.

 

[Dave2013M3]

Just got my car back a few days ago and I wanted to drive it for a few days before I gave any input on the swap. What can I say....

WOW!!!

This is the way the car should have came, I understand they would have slapped a Gas Guzzler Tax on the car, but who cares. I gladly would have bought it with either the Tremec gear ratios of the M1 or GT350 or the MT82D4 with 4.09s and the tax. The car should have came this way. It feels so much more alive.

It tightened up the driveline, 3rd and 4th is still a little too tall but definitely a step in the right direction. The car still feels very OEM, I am having no noise or added driveline slack the install was great. I had an issue with the ECU due to the installer not understanding the archaic ProCal, he mainly used HPTuners or SCT.

1st gear tops right out at 45mph while 2nd gear is 70, so nice and tight and very brisk off the line.

Here are the comparisons in speed.

3.73

4.09

 

[paulmustangv6]

2020 EU GT with 4.56 gear swap.
MGW short shifter, Steeda hydraulic clutch line.
PCM programmed through HPTuners and the BCM through Forscan, auto rev match work like OE.
Still need to work on speedometer calibration because it shows 5-8% more compared to GPS, but I really don't care much about it

 

[WD Pro]

2020 EU GT with 4.56 gear swap.
MGW short shifter, Steeda hydraulic clutch line.
PCM programmed through HPTuners and the BCM through Forscan.
Still need to work on speedometer calibration because it shows 5-8% more compared to GPS, but I really don't care much about it

Is it possible to do an idiots guide / step by step guide to everything that was done electronically ? (PCM & BCM)

Does the auto rev match work the same as OE ?

Thanks

WD

 

[paulmustangv6]

Is it possible to do an idiots guide / step by step guide to everything that was done electronically ? (PCM & BCM)

Does the auto rev match work the same as OE ?

Thanks

WD

yes, rev match works like OE
will make step by step quide soon

 

[Mikepol2]

Just got my car back a few days ago and I wanted to drive it for a few days before I gave any input on the swap. What can I say....

WOW!!!

This is the way the car should have came, I understand they would have slapped a Gas Guzzler Tax on the car, but who cares. I gladly would have bought it with either the Tremec gear ratios of the M1 or GT350 or the MT82D4 with 4.09s and the tax. The car should have came this way. It feels so much more alive.

It tightened up the driveline, 3rd and 4th is still a little too tall but definitely a step in the right direction. The car still feels very OEM, I am having no noise or added driveline slack the install was great. I had an issue with the ECU due to the installer not understanding the archaic ProCal, he mainly used HPTuners or SCT.

1st gear tops right out at 45mph while 2nd gear is 70, so nice and tight and very brisk off the line.

Here are the comparisons in speed.

3.73

4.09

Glad it worked out for you, Dave, that was definitely the best mod I did on the 2018.

 

[NeverSatisfied]

yes, rev match works like OE
will make step by step quide soon

Definitely interested in this, you’re the first one I’ve seen to successfully navigate programming a ratio greater than 4.09 in a 19+ car.

I

 

[Dave2013M3]

Glad it worked out for you, Dave, that was definitely the best mod I did on the 2018.

Enjoying it now even more with new tires. The Mich PSS gave up the ghost with 10k miles on them. With fresh rubber its even more impressive. Ford should have given us either the 2015-2017 Getrag gear ratios or put 4.09s in their from the beginning. The car should have came this way. I would have gladly paid the gas guzzler tax.

 

[Mikepol2]

Enjoying it now even more with new tires. The Mich PSS gave up the ghost with 10k miles on them. With fresh rubber its even more impressive. Ford should have given us either the 2015-2017 Getrag gear ratios or put 4.09s in their from the beginning. The car should have came this way. I would have gladly paid the gas guzzler tax.

Yeah the Mach with 3.73’s feels like the 2018 with 4.09’s… gas guzzler was $1,000 well spent!

 

[EgoBoost]

Maybe I should’ve tried this first instead of swapping my Vortech to a Whipple

 

[Mikepol2]

Maybe I should’ve tried this first instead of swapping my Vortech to a Whipple

LOL you’d have hated it with a blower. First gear would be useless.

 

[Dave2013M3]

My 2020 with just a Ford Performance power kit and the 4.09s are struggling in first gear. I can't imagine how bad it would be with the huffer.

 

[AZlb5.0]

My 2020 with just a Ford Performance power kit and the 4.09s are struggling in first gear. I can't imagine how bad it would be with the huffer.

I’m thinking of getting a huffer myself. Would 3.73 work or staying with 3.55 work better in your opinion.

 

[EgoBoost]

I’m thinking of getting a huffer myself. Would 3.73 work or staying with 3.55 work better in your opinion.

Go Whipple/Edelbrock/VMP if 3.55. Centri is not great with the 18+ MT82 gearing (hence why I switched).

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