So, I've read all over the forums about people changing their gears to 3.73 or whatever. I don't really understand the point, does it just put you in each gear for a longer amount of time or what? What are the specific reasons to change your gears? Sorry for the inconvenient question.
Thanks

 

People put in gears to have quicker acceleration and more seat of the pants pull in each transmission gear. A bigger gear (3.73s, 4.10s, etc.) means better acceleration at the exchange of a lower top speed.

In other words, people swap the gears because it can make the car more fun to drive.

 

The number is the gear ratio between the drive shaft and the wheel, so for a 3.23, the drive shaft turns 3.23 times for every one revolution of the wheel, with 4.10 gears, the drive shaft turns 4.1 times for every on turn of the wheel. You are applying mechanical advantage, the gears are simply a torque multiplier. More torque from the higher gear ratio means the car can get the weight moving quicker, but at the same time requires a shift at lower (mph) speeds and reduces the top speed of the car.
So, instead of say having to shift out of second at 60MPH and 6000RPM at a lower gear ratio, you may have to shift out of second at 50MPH and 6000RPM with a higher gear ratio.

 

Thanks guys that helped a lot. So if I'm in first and I'd usually shift out of 1st at about 2500rpm (maybe 10mph), then with a higher gear ratio it'd be like 2500rpm at maybe 6 or 7mph?

 

In theory, yes...but 7mph in first @ 2500rpms seems like it would require very steep gears IMO. Do you know what gears your car has now? Are you just roughly estimating that you are at that speed in that gear at that rpm?

 

The vehicles accelerate faster due to torque multiplication, gears are torque multipliers. For example if your car puts out 100trq at 2,500 rpm in 4th gear which is 1:1 ratio

100trq x 1:1 gear = 100trq x 3.31 rear gears = 331 trq to wheels

or

100trq x 1:1 gear = 100trq x 3.73 rear gear = 373 trq to wheels

This is basic explanation but I'm sure you get the idea

 

You pay to play. As stated, you lose a little top end but it's not like you'll notice unless you take the car to extreme speeds (and the drive shaft on the V6 will likely come apart at top end even with taller gears). You'll also cruise highway at a slightly higher RPM which will have a negative impact on fuel mileage but it may only be 1-3 MPG, depending on how steep you go.

Do you know what gears you have now? Most likely 3.31's. It should be stamped on the rear axle pumpkin cover and there's a code on your door jam sticker for the factory gears, providing the gears were not previously swapped. If they're 3.31's then 3.73's would be my recommendation (you may not feel much diff with 3.55's) if you DO do some highway driving; sort of the best of both worlds. Otherwise, 4.10's will make the car feel like a rocket off the line.

 

So how much torque are most gts putting out at peak RPM? because 300 x 4.10 sounds awfully high. 1200 ft-lbs of torque would be nice though

 

In real world conditions, you actually lose torque through the transmission. And not just a little, but ALOT. The 300ft-lbf torque at the crank becomes only maybe 250-275ft-lbf at the wheels assuming stock rear gears.

 

I would guess that the 320 spec torque is calculated based on 3.31 gears and fourth gear (1:1 through the transmission). Which would give a flywheel torque of about 96... extrapolate that out to 4.10 (90 x 4.10) you get 394. These numbers do not account for drivetrain losses.