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2019 GT rear end ratios

Cobra Jet

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Sorry but can I add a question to someone elses thread?

Photos below from my car which is a 2018 GT with MT82 (Australian spec - so a mix of PP1 and Premium I believe) with magneride.

Reading your info above it suggests that with the Iron housing, aluminium cover and temp sensor (which it has all 3) it should be a 3.73 with Torsen. I had read somewhere that the Aus Spec cars had the other LSD.

Apologies re the untidy black underseal.... I cleaned it off the sticker as best I could!

Is there any way to confirm either way?

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Hey Pete,

Feel free to always jump in anywhere - the more the merrier!

Your post and the follow-ups gives us more knowledge for sure. My response was geared (no pun intended) towards the US Spec S550’s. I don’t have any available info for the exports.

It would be cool to have a definitive S550 trans/rear diff ratio FAQ sheet for the US and Export S550s, as it would surely help out many on this site. More so when folks want to upgrade (or in some cases downgrade) their rear differential ratios due to Owner use.
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I Bleed Ford Blue

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On the sticker the 3L55 denotes a 3.55 gear and the "L" denotes limited slip. They use the same code here in the US
 

BlackandBlue

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3.55 will feel faster but 3.15 on the street will be faster.

3.55 are really good at spinning the tires in first and second. 3.15 a little less so.

At the track it seems to be a wash until you start getting tires, tune, transbrake, converter. Then 3.55 are beneficial.

If you want to spend $1500 on something a tune or lighter wheel setup would be more beneficial.
 
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Thephallking

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3.55 will feel faster but 3.15 on the street will be faster.

3.55 are really good at spinning the tires in first and second. 3.15 a little less so.

At the track it seems to be a wash until you start getting tires, tune, transbrake, converter. Then 3.55 are beneficial.

If you want to spend $1500 on something a tune or lighter wheel setup would be more beneficial.
Does 4.6 0-60mph seem correct?
 

Bmaughan

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I don’t really get all of the “spin the tires” comments... I have a Gt mt82 PP w/3.73s and a procharger making about 530-550 whp and I can keep 1st on the ground with ps4s’. I’m in Az so maybe temperature plays a big role.
 

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Thephallking

Thephallking

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Have y
I don’t really get all of the “spin the tires” comments... I have a Gt mt82 PP w/3.73s and a procharger making about 530-550 whp and I can keep 1st on the ground with ps4s’. I’m in Az so maybe temperature plays a big role.
Have you tried any 0-60 runs?
 

Bmaughan

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you got me there....i never really start from a dig...its usually slow rolling starts
 

Htk084

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3.55 will feel faster but 3.15 on the street will be faster.

3.55 are really good at spinning the tires in first and second. 3.15 a little less so.

At the track it seems to be a wash until you start getting tires, tune, transbrake, converter. Then 3.55 are beneficial.

If you want to spend $1500 on something a tune or lighter wheel setup would be more beneficial.
how do you know this? That the 3.15 is faster on the street and a wash in the 1/4 mile?

I’m in the middle of buying a car and this would really help out a lot, thanks.
 

Htk084

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I would get the 3.55 on my car if I was going to purchase again. The fun factor is worth the cost. These cars are just traction limited so extra gear is not going to help on the factory 275 tires. If you stay N/A I would go 3.55.
I was leaning toward the 3.15’s cause the car will be on stock 235’s, plus I can’t seem to find one in my area with 3.55s

I know the 3.55 is more fun, just like to know if it’s any faster. Car will be staying stock and I found a good deal on a 301A car. Thanks for your reply
 

Zinc03svt

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3.55’s are hard to hook on even 275 ps4’s much below 45 mph. Liking the warmer weather for sure. Feels like I have been driving on ice since November cool air hit.
 

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luv2spedup

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I have a 16 GT PP MT82 with a 3.73 Torsen. Car is Roush charged making near 600 whp. my issue is this combination makes the gears really short. On the drag strip in a 1/4 mile i have to shift into 5th, on hwy pulls i find my self going through gears.

My question is what are my options to have taller gear economically. My 11 Shelby had a torsen with a 6060 and that combination rocked..
1- Go with a lower ration rear.. 3.15 or 3.55
2- Save up for a 6060 swap
 

I Bleed Ford Blue

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I have a 16 GT PP MT82 with a 3.73 Torsen. Car is Roush charged making near 600 whp. my issue is this combination makes the gears really short. On the drag strip in a 1/4 mile i have to shift into 5th, on hwy pulls i find my self going through gears.

My question is what are my options to have taller gear economically. My 11 Shelby had a torsen with a 6060 and that combination rocked..
1- Go with a lower ration rear.. 3.15 or 3.55
2- Save up for a 6060 swap
Find someone local with an 18+ with an MT-82, and do a straight up swap. The 11-17 MT-82's were close ratio with 5th gear being 1:1 and for 18+ ford decided to change them to a wide ratio with 4th now being 1:1, just like the T-56 and the 6060. Since you are boosted now you don't need a close ratio box, and an 18+ owner who is staying N/A would love to have a close ratio transmission.

When ford changed the ratios in the MT-82 for 18 it actually slowed down the manual GT's even tho they got a 25 hp bump. The 0-60 times are unchanged on the manual cars between the 15-17 and the 18+ ones because of the new ratios. If an 18+ car had a close ratio 15-17 box, they would have an improved 0-60 time. And you, now with a wide ratio box would have less shifting and cross the line in fourth at the strip.

If you don't have the space, tools and skills to drop and swap two transmissions at the same time, find a local shop who will. While your in there, throw in a new clutch and enjoy. It should only cost you about the cost of a clutch job and the same for the other guy.
 

luv2spedup

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Find someone local with an 18+ with an MT-82, and do a straight up swap. The 11-17 MT-82's were close ratio with 5th gear being 1:1 and for 18+ ford decided to change them to a wide ratio with 4th now being 1:1, just like the T-56 and the 6060. Since you are boosted now you don't need a close ratio box, and an 18+ owner who is staying N/A would love to have a close ratio transmission.

When ford changed the ratios in the MT-82 for 18 it actually slowed down the manual GT's even tho they got a 25 hp bump. The 0-60 times are unchanged on the manual cars between the 15-17 and the 18+ ones because of the new ratios. If an 18+ car had a close ratio 15-17 box, they would have an improved 0-60 time. And you, now with a wide ratio box would have less shifting and cross the line in fourth at the strip.

If you don't have the space, tools and skills to drop and swap two transmissions at the same time, find a local shop who will. While your in there, throw in a new clutch and enjoy. It should only cost you about the cost of a clutch job and the same for the other guy.
Thanks for the input dude, that is actually a really good idea.. much appreciated
 

I Bleed Ford Blue

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I saw you were in Houston, it's a big city, there is bound to be someone nearby who would be interested in doing a straight up swap. Also, since LMR is somewhere in south Texas around the Houston area, they might be able to do the swap or point you in the right direction. Hell they might be able to help you find a willing counterpart too.

The wide ratio gear sets in the 18+ trans is slightly stronger than the close ratio 11-17 version. The early build 18's had cast aluminum shift forks and were prone to breakage. Ford has a TSB for that issue and has updated later builds. Make sure the donor trans has been fixed per the TSB and has the new updated parts, or a later build that has already been updated on the production line.
 
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Fly2High

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Just a thought to throw out there. The GT PP2 uses 305/30R19 tires and has a 3.73. In reality, the smaller tires will effectively change the ratio to a 3.94.

The point I am making is the tires/wheels you install will affect the performance not just in how sticky they are. You will see lots of guys switching to 20" wheels only to slow their car down because the wheel/tires get heavier and they reduce the final drive ratio all for looks.
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