Fugitive

So i guess what we're seeing here is that if you are going to beat that motortrend time of 12.8 in the 1/4 @110.8 , you will have to shift to 5th with the 3.73 gears near the finish line and that will slow you down.
Hmm makes me think that 4.10's might be a better choice if you are good at shifting cause you will need to shift to 5th earlier than the 1/4 mile line. And with drag radials earlier than that.
And if you add more power later down the road...

hawkeye18

Actually, a more viable strategy would be to shift to 5th around 105. That puts you just under 5k rpm, which is still well within its power band, and that gives you time to build speed by the trap. Top speed in 5th is 150, so you'll have plenty of room to breathe.

Crazy to think though, that you would shift to 5th for a quarter mile drag!

Gene K

Hawkeye it doesnt quite work like that. 3.31 to 3.55 gears in the 2005-2009 were worth 1/10 second.

In a test of tuner cars (Roush, Steeda, etc) with CAI/Tune and 3.73 Gears a standard car with 3.55 ran essentially the same times. The CAI/Tune and 3.73 were not enough to offset the weight gain.

I think you missed a few essential variables:
1. Both gears will be capable of spinning anywhere in low gear so no advantage.
2. The 3.73 car will lose more ET during the shifts (The sooner the shift the more ET you lose for a given amount of time because the car is covering less distance).
3.. While the 3.73 may give extra multiplication the 3.55 will be lower in the rpm range were the engine is normally making more torque so offset part of the difference.
4. After each gear change the 3.73 car makes the 3.55 car will continue in the lower gear for a little longer thus have the multiplication advantage for a short but significant period of time.
4. The 3.73 will force you to "ride the limiter" in 4th or shift and go through in the bottom of fifth.


On my 2007 4.10's were no quicker with the same 60' than the 3.55. Their isnt enough traction on street tires to cut any better 60' and anything you gain in 2nd and 3rd you gave up when you were forced to shift to 4th with the 4.10.

In my opinion the quickest combos:
Stock Trim - 3.55 - 7000 rpm @ 115 mph trap
Stock Trim plus 17" Bullets and 245/45R17 Nitto 555R's - 3.31 - 6900 rpm @ 115 mph Trap
CAI/Tune (with raised limiter) and 17" ET Streets (26.5" + Tire Growth) - 3.73 - 7500 rpm @ 118 mph

Those are for mineshaft air. If you dont run when its 1000' Below you will need to rework those numbers.

JMHO. That and a buck will buy you a cheap cup of coffee.

Sam I am

LOL at the mineshaft air. I haven't been to the Strip here in about 5 years, last time I ran the DA was around 1800ft. Granted, better than the actual altitude of 2300ft.

Gene K

The 3.55 you ordered will be super nice for a street car Sam.

Launching in low will be closer to a 2010 with 3.90 than 3.73
Launching in 2nd during everyday driving will be like doing so with 4.30 in a 2010
(Ask the 4.30 guys how many of them use 1st during normal driving.)
Overdrive will be like a 3.31 in a 2010.

On top of that add 20+ % more torque and I dont think you will suffer from a lack of gear.

Sam I am

I had 4.10's in my 98 TA 6-speed, and usually went from first to third on the street.

drew2000

So...I'm starting to rethink this if I order a 2011.....
Maybe the 3.31's -would- be a good choice for all-around street driving/back twisty road stuff if you can live with a few-tenths off the 1/4 mile.

With the new gearing ratios and the big increase in power, the 3.31's might be the way to go. Hope 412hp+ is enough to still do the odd smoky-burnout with a 3.31 rear-end.

MrSandman

Make sure you get reeeeealy good tires if you plan on using taller-than-stock gears... It sounds like, at least from this review, that you may have some traction problems. Without traction, extra HP and gears arent going to mean crap... It will be especially apparent when your losing "stop sign to stop sign" races to lesser cars


I want this car bad. Real bad.

Quote:
"Comparing this 412 horsepower V-8 power to the 2003-04 SVT Cobra's 390 horsepower Bengt says the new Mustang GT's power slams the old Cobra model. He even goes on to say the level of thrust is awfully close to what you would get from a GT500. If the level of thrust and pull through the gears is more than the 2003-04 Cobra Ford has one scarry Mustang on their hands.

Talking about the torque Bengt says there is so much on command, even just above idle and you most certainly have to roll into the throttle carefully out of tight turns. This has been true for the Shelby GT500 and older Cobra models but now drivers will have to be a little more aware of their surroundings with the type of power under the hood. Drivers not use to the power might be in for a surprise and even some might not be able to handle it."

Article:

http://www.mustangblog.com/blog/1043...nd-first-drive

Gene K

How easy it will be to spin in first will have more to do with the amount of torque management Ford put in the PCM than the gears in my opinion. I dont believe for a second it wont have at least a max rate at which the throttle will open (like the 3V). It wouldnt do for Aunt Susie to hit a bump going through a turn in second and launch herself into the patrons in the window tables at the local diner.

Driver72

As you said, "should" but in reality probably WON'T be the case.
Again, as I stated in a post on page 2, the 3.55 gears may have advantages in launching and traction on shifts.
So in reality of someone gets a 12.8 on 3.73's but struggles a bit for traction and broke the tires loose a bit in the shift to 2nd, somebody with a 3.55 MAY be able to launch the car a bit better without breaking the tires loose, and same with the shift to 2nd not spinning as much. Therefore they could end up with the same 12.8 run.
Further, as stated, if/when someone mods the car with intake, exhaust, tune, they made add 40+ rwhp to the car allowing for faster traps.
If those faster traps means it is now necessary to shift to 5th, with the 3.73's that means an extra .2 seconds than for the shift and corresponding lag in acceleration right at the time when you want to be in full acceleration.

Personally, and I'm guessing here, I'd say the 3.55 gears would drop you about .15 seconds and 1 mph over the 3.73's on stock power.
With 30-40 hp over stock I'd bet the 3.55's and 3.73's would be within .05 and .5 mph of each other, again on stock tires.
The more power the car makes the more critical traction becomes and with the 3.73's that's even more of an issue.

I'd say for the "average' enthusiast the 3.55's are an ideal ratio.
For the guy who wants maximum acceleration for stock (or near stock) power levels or rolling runs, the 3.73's will be best. supercharge the 5.0 and have 500-550 whp and the 3.73's may be a handful for getting power down.

Will be interesting to see how things work out.