As I continue to investigate which car I'm going to buy and what upgrades I'm planning I've come to the conclusion that a super charger is actually a possibility for a me. I've heard some people say if you know you are going to add a super charger on the new cars to stick with the standard rear end gear and don't upgrade to 3.73's because of MT82 gearing. My original plan was a 2014 with Track Pack but if this is true then I might just stick with the standard car. Then again the Track Pack still has other goodies that make it worth while and I could always "downgrade" my gears.

Any thoughts?

The car will be driven daily during nice weather.

 

I just added a Roush TVS and my 3.73's are manageable with the blower i like the acceleration they give for a DD. Only hang up is the gear whine and some guys say they get it from the factory ,ill most likely put 3.55's in mine eventually the gear whine is starting to become annoying. I originally had 3.31's and if i knew at the time i was going to get a blower i would have just left them in. If you stay NA then 3.73's are the way to go and hope you dont get any whine

 

I think 3.55's would be perfect for my car... and with a supercharger I can't imagine wanting 3.73's. 5th gear tops out at low 140's or so and 6th is a real overdrive. 3.55's give a bit longer legs with each gear. I wish they offered 3.55's as an option with the track pack

 

5th with the 3.73 tops out at 150 at 7000 rpm , thats another reason I want 3.31's back is top of 5th is 170

 

Well my track pack car is arriving today. If I get around to adding a supercharger I'll make sure I'm prepared to drop back to 3.55's or 3.31's at the same time. I'll drive it with the 3.73's for a bit first of course.

Thanks guys.

 

Do you live in Germany? Where do you plan on going 150 let alone 170?

 

If you check the specs on the GT500, you will see that it ships with 3:31 gears as well. If you go with a blower, might be a better option to stick with that gearing to start with.

 

I plan on doing Texas mile next year so I have some time but will most likely put the 3.31's back in

 

The gearing spreadsheet seems a little optimistic - my car (per GPS speed and OBDII RPM readout) is about 1.5% lower in each gear than the spreadsheet shows. But close enough... like you said, you'd be closer to 170 in 5th with 3.31's, which for some people is more appropriate gearing. Very much dependent on what you want to do with the car of course!

1st and 2nd gear with 3.73's feels FAST

 

Yes it does! With a supercharger I think I will definitely consider going down to the 3.31's though.

 

I have a supercharged GT and a GT500. The GT500 trans gearing is totally different than the GTs, most GT500 owners want to go up to 3:73s because 3:31s make the gears soooo long, 65mph in 1st gear! My Roush has 3:73s in it and I like them, but they are definitely borderline excessive in some situations; like having to shift into 5th in the 1320 . But in the GT500 with 3:73s I can cross the line (barely) and stay in 3rd.

 

Gear whine is just a bad install. I know at least 20 people in my Mustang club with 3:73s and 4:10s and not a single one whines, if it had whine our mechanic took it apart and made the necessary adjustments that fixed it every time. All these cars are different as well; stock shocks and springs, lowered, 1-piece DS, etc.

 

I have a base 2011 Gt 6 Speed with 3.73 gears and Vortech blower. I really like the way it works together... 3.73 gears are fine.

 

For the street a blower with 3.73s is fun. If you plan on taking it to the strip though you'll basically be shifting immediately after launch. If its a strip car 3.31 would be the best choice.

 

Yes.

 

Just got a set of 3.31's and i plan on getting them in in the next month or two.

 

Backlash is the issue and needs to be corrected by adjusting pinion depth and/or side load on the ring gear if the rear end whines, barring some sort of failure like bearings.

 

how do 373's work on an auto?

 

Not as good as 3.15's.

 

Useful tool I used this to spec out my gear ratio for my new tremec magnum xl being installed today! Going with 3:90's in the rear which is the equivalent of 3:31s in an mt-82!

http://xse.com/leres/bin/gearratio?t...le=35&wheel=19