i saw where they said the 11 had 3.31. our conventional wisdom(although somewhat up for debate) was that with the 4.6 3.73s for manual and 4.10s with auto with 3.73 being the best overall gear.

What about the 2011? this engine has a much higher rev limit. that coupled with higher HP,how will this affect the overall drivability with 3.73? also gears are prob the best bang for buck mod out there. Now remember most say with boosted cars that is generally better to keep it closer to 3.55 or 3.73.

Just want to get your guys views on this.

 

There is another thread somewhere with the exact gearing numbers search "new gear ratio comparison" from those numbers to me it looked like the 3.55 matched the new 6speed manual best. you get slightly better multiplication in 1st than a 2010 3.73 and a better cruise in 6.

 

For the 2010 model year, the 3.73 axle was part of a package that also included upgraded front calipers and upgraded brake pads front and read. It sounds kind of like that brake upgrade is now standard on the GT. So will the 3.73 axle just be stand-alone option now? If so, I'm thinking I would also choose the 3.55 as the best combination of performance and fuel economy.

 

Because it now has a six speed, the rear end gear will have less of an effect on acceleration.

 

Going to an M6 with the 3.31 does some good things for the new Mustang; less parasitic loss from the final drive (on the GT500 going from a 3:31 to 3:73 saps around 25-30hp but is compensated by the increase in torque) and the really nice thing about the new transmission is its performance orientated piece - its an M6 with a single overdrive.

IMO I'd wait and see what happens when the magazines get hold of the 5.0 M6 combo and start throwing gears at it. It might just be that the new combo will get significantly less benefit from the gear swap.

 

I never thought I would write this but 3.73s or 4.10s might be too much gear for the 6M. Edmunds swapped gears in a Genesis V6 from 3.5 to 3.9 and times did not improve. They did mention the car felt much stronger on the race track.

 

Wouldn't the same theory cross over to a 2011 where it be like the TR6060 with a 4.56 gear gets you close to a 4.10 feel if you had a 5spd.

 

I guess so. The new tranny should be 10 percent or so deeper than the old 5 speed in first and second. I'm guessing 4.56 would be close to 4.10 in 1st and 2nd. The gap gets bigger in 3rd and 4th gear. So in the higher gears its more like 4.92. I'm guessing that's too much gear for a DD or weekend racer.

 

So do you think the 3.73 gear would be too much?

 

Too much is a relative term. I'd say 3.73 is about as deep as I would want to go. In contrast, I would have gone with 4.10s on a 2010.

 

Once somebody has done some instrumented testing, somebody here can probably calculate some fairly accurate projections for the alternate gear sets.

 

OK, thanks for the answer!

 

I'll see the occasional post that says they are getting the 3.73 limited slip axle. Isn't a limited slip differential standard, regardless of the axle ratio? I would think that even the V6 models would come standard with L.S., at least for 2011.

 

Every V8 Mustang since 1985 has left the factory with a Traction-Lok axle. Starting in 2011, V6 Mustangs will finally get a limited slip axle as standard equipment, too.

 

3.73 would be perfect for drag racing, as you would use nearly all of 4th since its a 1.31 ratio in the trans. It still leaves a little left for mods, as at 7000 rpm you would be turning about 114 mph.

 

I dunno, but I'm interested to see what everyone thinks about the various ratios in-practice, so I can take advantage of the experience

 

I've always set up my gears based on the 1/4 mile dragstrip. I want to cross the finish line in the 1:1 ratio gear. In the new 6-speed manual, that's 5th gear. Assuming that I would mod the car to run about 12 flat at around 115 mph in the 1/4 mile, I'd need 4.88 gears to turn 7K rpm's @ 115 mph. Or, if I planned on crossing through the traps as noted in the quote above, then 3.73 gears might be a little too steep as they'd be about 114 mph @ 7K rpm's. 3.55's would yield 120 mph @ 7K rpm's in 4th.

The 2nd consideration I use for choosing gears is rpm's on the highway. I can't tolerate anything over 3K rpm's at 70 mph. With a .65 overdrive in 6th gear, even 4.88 gears would only be turning 2,800 rpm's at 70 mph. My '07 GT automatic turns the same 2,800 rpm's at 70 mph, but with 4.10 gears, so the '11 GT will allow for more gear while keeping cruising rpm's constant.

So, for my intended use, I would likely pick 4.88 gears (maybe 4.56's?) and make that car scream through 5th gear at the dragstrip.

 

Brian, what do you recommend for someone like myself? My 5.0 will hardly ever see strip or track duty. I am only even considering getting a different gear set because its a factory option thats a lot cheaper now than if I want to add it later.

Will it make acceleration noticeably for someone who just might get on it every now and then?

 

Gears are - by definition - a torque multiplier. So, yes, you will definitely feel quicker acceleration just in everyday driving. Steeper gearing is one of the more gratifying mods for our Mustangs and is, therefor, one of the most commonly done mods.

Back to that torque multiplication. Let's say you take an '11 GT that has 390 lb ft or torque and has 3.31 gears. Adding 4.10 gears yields about 25% more gearing, which would give the same seat of the pants feeling as keeping the stock 3.31 gears, but adding 25% more torque (up to 485 lb ft torque). Can you imagine how awesome the car would feel with 485 lb ft torque? That's what a stock '11 GT with 4.10 gears would feel like.

You'll find less need to downshift, as each gear will pull much harder than stock. You'll lose just a little bit of fuel economy (maybe 1-2 mpg at the very most on the highway). The 3.73 gears from the factory will be a nice upgrade for your intended driving. Go for it and do not fear the gear!

 

Jason, I drove a leftover 09 and a 10 with the 3.73s back to back. The 09 had the 3.31s. Granted, the 15 extra hp may have made a difference, but the car picked up so much more in 1st-3rd gear. It was also easier for me to take off in 1st (I have pretty limited experience driving a manual on the street) because the engine revs were higher in the 10. I think if I get my 11 I'm *definitely* going with the 3.73s.