I own a 15 gt base model automatic with JLT CDI and Bama tune was looking to do the gears as an old fox body guy I thought the 373 was a no brainer but have read several threads on the gears in the auto being to high and the 373 being to much gear. So now I would like some input from you guys 373 or 355?
Best Gear Ratio
- Thread starter doughboy305
- Start date
Sounds like your fox body friend is still stuck in the stone age. No need to swap gears with these autos.
most people keep stock or go 3.31. there are some people that go higher of course but it doesnt seem to be effective. the 1st gear in the auto is really short which seems to be too much when paired with a 3.73+
I had 3.73s in the 2012 GT and now have 3.55s in the EcoBoost. I feel that 3.55 is the all-around best gear for these cars, but it really depends on personal taste.
AMWill
Active Member
Hey dough,
Great question and it is definitely one that can go back and forth. Even though I personally run 3.73's in my personal 2014 GT, I would go 3.55's in your auto!
Hope this helps and let me know if you have any questions.
-Will
Well I have an auto GT and went with the 373's and I am glad I did, it really woke the car up. I thought it would be to much for first gear but it is not. I just wish ford would make it an option so I didn't have to pay to get it done after the fact.
Love my 3.55's. I think they're just right.
Yours is a manual, this discussion was about autos. Which have even steeper gears in the transmissions than the manuals.
I'd still take 3.55s with the auto. Have both a manual and auto in the garage right now.
Maybe. But when guys start talking 3.73's and even 4.10's I just laugh.
My 2011 went 11.2 N/A on stock 3.15's. Hence the reason I believe it's possible to over gear these autos.
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Only 1st and 6th gear are steeper in the auto, 2nd, 3rd, 4th, and 5th, are steeper in the manual.
Auto spec's Manual spec's
1st 4.17 1st 3.657
2nd 2.34 2nd 2.430
3rd 1.52 3rd 1.686
4th 1.14 4th 1.315
5th 0.87 5th 1.00
6th 0.69 6th 0.651
https://media.ford.com/content/dam/fordmedia/North America/US/2015_Specs/2015_Mustang_Specs.pdf
This is why I went with the 3.73 vs 3.55. I did have the 3.15 but adding the 3.73's and the Torsen diff. was just amazing. I thought is might be to much but its not the car runs great with these gears!! :beer:
Tom
i ran 373 gears in my 13 gb paxton car that ran 9.1's near 152mph....i loved the first gear 1.35 60's i would cut on a regular basis....i would top out in 4th about 50 feet after the quarter was over around 7500rpm. some people left 315's in there car and would either finish the 1/4 in 3rd or just as it shifted into 4th...I personally liked to have the car finish hard at a top of a gear, 373's for me with 275/60 Pro Dr's was my combo. Ive seen many combos that kept the stock 315's and had success. Ill be keeping the factory 315 gears in my new base auto this time.
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Is there a gear ratio higher than 3.73? 3.90 or 4.10's on these 2015+
No there isn't and there's no need for it.
I have the 3.15's in my wife's 2015 GT vert. and of course 3.73 in my Boss. I was thinking about changing the GT but after a couple of drag races where the GT was right beside the Boss I decided the 3.15 is awesome for the GT. Zero wheel spin, just floor it and it goes!
with cams and springs for a higher red line, 4.09 gears would be awesome.
I currently picked up a '16(auto) that has 3:55s installed would this be a good starting point on the 1320 with bolt ons?
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