Question about rear end gearing on 2015 GT. Which best?

[BADBOSS]

Question about rear end gearing on 2015 GT. Which is best?

So I just got my 2015 Race Red vert. automatic for the wife on Saturday. We love everything about the car and feel it is a step change better than my 2012 Boss in most ways. The only thing I don't like, besides exhaust being to quiet (already ordered exhaust) is it feels slow to get going. My boss seems so much quicker and I assuming it is gearing because the power is close to the same. My 2015 has the 3.15 vs. 3.73 in the Boss so I guess my question is... has anyone changed the gears in an IRS yet? Is it a much bigger deal than the straight axle? Does the auto transmission need to be re calibrated?
Which ratio should I get? I am thinking 3.55, but would love to hear from others.

 

[5.0jake]

You also have the heaviest trim GT which I'm sure is slowing you down a bit more.
In the 11-14 GT's it has been said you wouldn't be gaining anything going higher than 3.31's.
Keep in mind the 6R80 transmission gearing has an aggressive first gear regardless of the 3.15 but 2nd-5th are longer than the MT82 (manual).
The 3.55's seem to be a pretty good match for the 2015 auto GT's and I'm sure would wake things up a bit for daily driving . If I were you I'd go test drive one before doing a swap.
As far as swapping gears with the new IRS, I am curious too.

 

[BADBOSS]

Bump for answer...

 

[PIKE5.0]

355 is the most optimal gear with the MT82.. No clue on the auto, bc I'm a man.

BUT.. I have 373, going to swap to a 355. As soon as the gear kits come out, which they haven't to my knowledge.

 

[Voltwings]

it needs a tune more than it needs gear, but the gear will require a tune, so that will mask the true results. Tune really wakes these autos up. The gearing between the transmissions is so different you cant compare rear gears between the two. Stick with the 3.15 for now, get a tune, and THEN make a decision.

 

[BADBOSS]

Thanx for replies. Based on the feedback and fact that it really isn't broken in yet I am going to wait and see. The car is is really a highway cruiser for her and the the 3.15's are perfect for that

 

[bunk22]

355 is the most optimal gear with the MT82.. No clue on the auto, bc I'm a man.

Because you're man lol I flew jets of aircraft carriers, can I join the man club too? I have the auto as well but with 3.55 gears and it does okay. But my old 2012 Mustang GT was a 6-speed with 3.31 gears and modded, not a good comparison.

 

[Branhammer]

Because you're man lol I flew jets of aircraft carriers, can I join the man club too?

No. You still have to drive a manual as well

 

[bunk22]

No. You still have to drive a manual as well

lol :-D