Did Ford Ruin their Manual Trans? - Engineering Explained

[saleen367]

I thought this would make for good conversation in the main S550 forum.

The 2018 Ford Mustang saw quite a list of improvements. Most notably, the engine increased in horsepower, torque, and redline RPM. Now with 460 horsepower, 420 lb-ft of torque, and 7,500 RPM, surely the new Mustang is quicker to 60 mph than its predecessor! But... it isn't. Motor Trend has tested both cars at 4.4 seconds. Why? Well in 2018, Ford significantly altered the manual transmission Mustang's gear ratios. And it added a 10-speed automatic transmission as an option. Check out the video to see why the 2015-2017 Ford Mustang GT features the best gear ratios, and what effects changing the ratios of the new Mustang had on performance.



It's a typical complaint of guys/gals for HPDE. Poorly spaced gear ratios. I believe @steveespo did a swap to a `17 for this very reason.

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[Schwerin]

I'm pretty sure the changes were made both to help MPG for EPA ratings, and to make the 10spd look better.

1st aside, the gearing is almost just like a 3650 with 0.10 added and a gear wedged between 4th and 5th. The 6th in the new 82 and the 5th in the 3650 is identical.

The 3650 guys LOVED the 4.10 for a fun daily and the 4.30 or .56 for the drag strip. I have a feeling the same can be said for the new 82. The 4.09 makes the gearing more like the 15-17 82, and the 4.30 and a 4.56 would be great for drag use.

That said, if my tranny blew tomorrow I'd probably look for other options to put back in.

 

[vernonator]

Thanks for posting that ...very interesting (love the Science EE uses to explain things). I guess I have the best of both worlds, I have a '16 GT w/pp AND the Ford Power Pack that puts me right in the 2018+ HP/Torque range but keeps the good ratios of the '15-'17...yeah me!!!!!

 

[Norm Peterson]

I'm pretty sure the changes were made both to help MPG for EPA ratings, and to make the 10spd look better.

I really think the idea was to eliminate the huge gap between next-to-top gear and top gear that had normally been Ford's gearing philosophy. There are plenty of situations where either 5th in a TR3650 or 6th in the original MT82 is too tall, and the next gear down is too short.

However, I doubt that making the A10 look better was a significant reason. I'm sure that Ford had already written off any notion of selling very many MT82-D4's to those seriously involved with drag racing and/or its unofficial street cousin.

1st aside, the gearing is almost just like a 3650 with 0.10 added and a gear wedged between 4th and 5th. The 6th in the new 82 and the 5th in the 3650 is identical.

5th gear in the MT82D4 is what the 3650 needed to have from the get-go. On the other hand, the MT82D4 could perhaps benefit from having the 3650's 2nd and 3rd gear ratios.


Norm

 

[Zinc03svt]

Ford just got cheap and outsourced it to China. I’d own one if it came with a real Tremec.

 

[nastang87xx]

Perspective, if you look at a Zeta platform Camaro SS with the LS3 and its torque curve and the Gen 3 Coyote, there's a rather compelling argument for the new gear ratios.

 

[nastang87xx]

Ford just got cheap and outsourced it to China. I’d own one if it came with a real Tremec.

More perspective, Tremecs are made in Mexico.

 

[cosmic charlie]

More perspective, Tremecs are made in Mexico.

By Mexicans!

 

[nastang87xx]

By Mexicans!

 

[boB]

Ford rates the xmsn for a max torque of 480 n*m in the 2019 service manual, this is far less than the engine spec of about 570 n*m. One way to increase the torque capacity of the xmsn (without changing the dimensions) is to go to a lower numerical first gear. Ford did this, possibly to help the xmsn reliability with the new engine.
The new ratios work well for the street, maybe not so good for the track.

 

[H@mmer]

I really think the idea was to eliminate the huge gap between next-to-top gear and top gear that had normally been Ford's gearing philosophy. There are plenty of situations where either 5th in a TR3650 or 6th in the original MT82 is too tall, and the next gear down is too short.

However, I doubt that making the A10 look better was a significant reason. I'm sure that Ford had already written off any notion of selling very many MT82-D4's to those seriously involved with drag racing and/or its unofficial street cousin.




5th gear in the MT82D4 is what the 3650 needed to have from the get-go. On the other hand, the MT82D4 could perhaps benefit from having the 3650's 2nd and 3rd gear ratios.


Norm

Maybe I'm odd, then. I love how 1-5 in my car is tightly spaced and relatively low. Then I have this huge jump to 6th. So playing in the mountains is fun because i get to rip around gears without going crazy fast. But then I get on the interstate and still run reasonably low RPMs even with a low geared differential.
The gearing on my 2017 is nearly perfect for me.

 

[Schwerin]

Ford rates the xmsn for a max torque of 480 n*m in the 2019 service manual, this is far less than the engine spec of about 570 n*m. One way to increase the torque capacity of the xmsn (without changing the dimensions) is to go to a lower numerical first gear. Ford did this, possibly to help the xmsn reliability with the new engine.
The new ratios work well for the street, maybe not so good for the track.

I mean fords cheaped out on that before. The tranny in the 98-03 Escort ZX2 made 127ft-lbs and it had a trany built and designed to support 90. It was very easy to break that diff with just good tires. They tried to fix it by making the gearing a bit less aggressive in cars made after 99.5, then later they messed with the ECU so bad the cars went from dynoing 115-120WHP down to making 100-105.

 

[nastang87xx]

I really think the idea was to eliminate the huge gap between next-to-top gear and top gear that had normally been Ford's gearing philosophy. There are plenty of situations where either 5th in a TR3650 or 6th in the original MT82 is too tall, and the next gear down is too short.



Norm

In all seriousness I do think the GT350 is a great candidate for a 7 speed. 4th goes to 137MPH and 5 is 175MPH.

1st, 51
2nd, 78
3rd, 108
4th, 137
5th, 175
6th, LOL

For my personal track experiences, great ratios would be something like:

1st, low 40's
2nd, low 70's
3rd, high 90's
4th, mid 120's
5th, high 150's
6th, whatever
7th, HA!


A Challenger/Charger Scat Pack is almost into 3rd by the time the GT350 is getting out of 1st.

 

[3pdl]

my '19 never sees 6th and rarely 5th. i'd enjoy the earlier ratios more on the street. however, at barber, redlining 3rd on the front straight and not needing 4th is pretty sweet

 

[Norm Peterson]

In all seriousness I do think the GT350 is a great candidate for a 7 speed. 4th goes to 137MPH and 5 is 175MPH.

Agreed. Not sure what mph targets I'd look for in each gear, though. Haven't run any numbers for that one.

For my personal track experiences, great ratios would be something like:

1st, low 40's
2nd, low 70's
3rd, high 90's
4th, mid 120's
5th, high 150's
6th, whatever
7th, HA!


A Challenger/Charger Scat Pack is almost into 3rd by the time the GT350 is getting out of 1st.

Your proposed speed ranges for the first five gears are actually pretty close to what I'm looking for, for my '08, where 5th is really the 'whatever' gear and 6th is 'HA!'.

You must be looking at really short tires and a really deep axle ratio, 'cuz I've worked out the numbers below using 25.9" tall tires and 3.73's in the axle at only 6000 rpm using an available transmission.
47
70
96
125
156


For a road course car, what you generally want is for the gear spacing to get closer as you go up through the gears, for at least a couple of reasons. Aero resistance gets bigger, so the faster you go, the more you want to be able to stay closer to peak power. Plus, and greatly simplified, it keeps the mph ranges more comparable - 1.5 to 1 gear spacing is good for 70 vs 47, but starting at 100 mph, a 1.5 jump to the next gear puts you at 150.

You've got a lot more power and rpms available than I have, so I haven't put much time into seeing what I might choose if I had 7500 rpm and 450-ish HP available. But for road course use I think a Tremec with 2.97/1.78/1.30/1.00/0.80/.063 ratios has better gear spacing than anything that Ford has offered. Closest I can readily find in the Magnum XL series uses a 2.66 1st gear (all the rest are the same), which is a bit too tall for easy launching from a stop on an upslope.


Norm

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