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3.73 rear gears on a v6?

pinero61

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As beast said it will spin the tires faster at a given rpm/gear.

More importantly, it makes it easier for your drivetrain to begin moving and keep the tires moving within an effective speed range.

At higher speeds, the engine will have to rotate faster to maintain the same speed. This is where the loss to fuel economy comes in.

Power vs economy is and always has been the main battle in gearing selection. However, the newer auto transmissions (8-10 gear) are are allowing people to run low and high effective ratios with the same setup. Best of both worlds.
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With the 3.73's on the stock Pirelli's I hit 58-58 at the top of 2nd, I've since raised my rev limiter to 7200 so I can get to 60 in 2nd.
 

Northern Stallion

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With the 3.73's on the stock Pirelli's I hit 58-58 at the top of 2nd, I've since raised my rev limiter to 7200 so I can get to 60 in 2nd.
I have 3.55's and also have to shift to 3rd to hit 60. How did you raise your rev limiter?
 

pinero61

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I can hit 60 in second, but I'm redlining to do so.

3.73's.

As far as I know, we have the same transmissions in the GT as the v6.
 

dgc333

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I have 3.55's and also have to shift to 3rd to hit 60. How did you raise your rev limiter?
I have an SCT X4 tuner. It allows you to adjust the rev limiter in 100 rpm increments. I raised mine to 7200 to see if I could get better times with only one shift to second.
I have found with my Ecoboost it is no quicker hanging onto second to 60 than shifting into to 3rd right before the power peak around 5500 rpm.
 

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pinero61

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I have an SCT X4 tuner. It allows you to adjust the rev limiter in 100 rpm increments. I raised mine to 7200 to see if I could get better times with only one shift to second.
I have found with my Ecoboost it is no quicker hanging onto second to 60 than shifting into to 3rd right before the power peak around 5500 rpm.

The ecoboost does not make top end power due to the size of the factory turbo chargers. The 5.0 makes power up to 7500, but I have not seen a dyno graph on the 3.7 yet.
 

Jon|3.7

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this is my next mod, i would like 3.73 but not sure how that would be for a daily, 3.55 sounds good as well, any thoughts? and what exactly will i need to make this happen, i hear a lot about "pumpkin" or "just pinion and gears", thanks!
 

USMCtoARMY

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this is my next mod, i would like 3.73 but not sure how that would be for a daily, 3.55 sounds good as well, any thoughts? and what exactly will i need to make this happen, i hear a lot about "pumpkin" or "just pinion and gears", thanks!
I have had both sets of gears on my previous mustangs. The 3.73 was the more fun gear with 2-3 mpg loss, more than that most days. The 3.55 felt great too and had 1-2 mpg loss, but not as exciting as the 3.73. For a DD that drives more than 20 miles a day to work I would go 3.55 for sure. If your stang is your second car get the 3.73 gear. So much fun with those.

Curious I still haven't seen anyone post the actual complete breakdown with everything needed to do the swap on the IRS pumpkin. The old gen was simply the diffs, install kit, and a reliable transmission shop. I have seen so many opinions on this forum about a while pumpkin swap vice getting diffs. Anyone have a complete breakdown and projected costs?
 

Xavier

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I upgraded the gears in my 2012 V6 from 2.73s to 3.73s and thought it was a fantastic pairing. The Cyclone definitely likes to rev so it worked really well. Fuel economy dropped from 31-32 highway to 26-27 but it was well worth it.
 

USMCtoARMY

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I upgraded the gears in my 2012 V6 from 2.73s to 3.73s and thought it was a fantastic pairing. The Cyclone definitely likes to rev so it worked really well. Fuel economy dropped from 31-32 highway to 26-27 but it was well worth it.
Exactly.
 

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Jon|3.7

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I have had both sets of gears on my previous mustangs. The 3.73 was the more fun gear with 2-3 mpg loss, more than that most days. The 3.55 felt great too and had 1-2 mpg loss, but not as exciting as the 3.73. For a DD that drives more than 20 miles a day to work I would go 3.55 for sure. If your stang is your second car get the 3.73 gear. So much fun with those.

Curious I still haven't seen anyone post the actual complete breakdown with everything needed to do the swap on the IRS pumpkin. The old gen was simply the diffs, install kit, and a reliable transmission shop. I have seen so many opinions on this forum about a while pumpkin swap vice getting diffs. Anyone have a complete breakdown and projected costs?
my job is exactly 20 miles away lol

3.73's sound like i would enjoy (but will mine being auto differ?)

my mpg is 22.1 well on the info screen
 

USMCtoARMY

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my job is exactly 20 miles away lol

3.73's sound like i would enjoy (but will mine being auto differ?)

my mpg is 22.1 well on the info screen
Limited experience with auto. Always have owned manuals, but the auto guys prefer the larger gear ratios. In the s197 days manual drivers we usually went 3.73 and auto went 4.10 and with the addition of any extra gear and better motor my thoughts are the 3.73 would be a great setup in the auto. Is your drive more city? Heck with stock ratio on my 40 mile commute I was averaging near 30 mpg.
 

Jon|3.7

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Limited experience with auto. Always have owned manuals, but the auto guys prefer the larger gear ratios. In the s197 days manual drivers we usually went 3.73 and auto went 4.10 and with the addition of any extra gear and better motor my thoughts are the 3.73 would be a great setup in the auto. Is your drive more city? Heck with stock ratio on my 40 mile commute I was averaging near 30 mpg.
all highway, but houston traffic weekdays sucks, plus i like driving fast, damn 30?! highest ive ever got was 24, but i'm on 20's

i will go with 3.73 gears then!
 

V6junkie

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Never done gears before and I have an auto and I'm sure this has been asked but what all would I need if I wanted to upgrade to 3.73s..... different differential?.... just the gears?..... is their a full kit? I'm interested in doing this just want to make a plan to go forward with it
 

fordguys550

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I have 373s for mine just havnt put them in yet. 3.7 pulls hard to 7k....so alot of gear is a good thing....especially with the lowish tq down low
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