curtishd

Could someone explain the different gear to me and the pro's and con's of each? Thank you.

akumaky

you mean like 4.10s and the like?

thewarmachine

The different gears...1st, 2nd, 3rd, 4th, 5th.....are in fixed ratios in your transmission. When people get "gears", they are getting replacement differential gears that change the ratio of how many times the driveshaft rotates per one rotation of the wheels. My stang has 3.31 gears, i.e., a ratio of 3.31:1....driveshaft rotations to wheel rotations. If I were to get 3.73 gears, my driveshaft would rotate 3.73 times for every one rotation of the wheels. Therefore, the engine would gain a better mechanical advantage in trying to turn the wheels. Based on our cars' specific power range, this means quicker acceleration. Of course, there is a point at which the ratio becomes counterproductive. For a fixed rpm number, when you go up on your gear ratio, you're sacrificing speed for power.

Here's a simple thought experiment. Suppose you had 3.31 gears and you upgraded to double the ratio...6.62 gears. Your car's new 1st gear would really be like a 1/2 gear, your new 2nd gear would be like your old 1st gear, your new 3rd gear would be like a 1.5 gear, your 4th gear would be like your old 2nd gear, and your 5th gear would be like a 2.5 gear. Each gear is twice as powerful as before, but half as fast.

Hope this helps.

Nuke

A higher gear ratio will net you a better 0-60 MPH time but since the engine will turn more RPM's at a given speed it'll increase your fuel consumption a bit and, with the higher gears, limit your top end. The range of gear options can give a decent balance.

Gene K

6250 rpm + 4.30 = 168 mph (A speed I doubt these cars can obtain on flat ground, LS1 Camaro is good for 159 mph)

CAI + Tune + 6250 rpm = -5 rwhp from peak.

So you lose what? 1 mph if that?

I would hardly call that limited top end.

Nuke

From the "Mustang Transmission Gear Ratio Calculator" spreadsheet that I found through the forums here, my THEORETICAL top speed with my 3.55 gears and tire size is 221.55 MPH. When I plug in 4.30 gears, my theoretical top speed is reduced to 182.91 MPH. Although I may never SEE a reduced speed since I haven't nor plan on driving over 120 MPH, I believe that can be considered "limited" top end.

Caution

Well choosing the right gear ratio for your stang can get you some great performance... not necessarily more RWHP gain, but better utilization of the factory power. A gear ratio is the number of teeth on the ring divided by the number of teeth on the pinion. So lets say you take 3.73 for example -- you take the 41 teeth on the ring divided by the 11 teeth on the pinion and you get 3.73 (it's really 3.727272 that repeats it's self but rounded is 3.73). Don't think that the bigger the gears the better either -- bigger gears generate more heat in the differential and could cause fluid break down. Some things that may dictate your gear choice are your tire size or if you have an automatic tranny -- typically I would recommend 3.73 for an auto and 4.10 for a manual. --

If you upgrade from your factory/ stock 17's to 20's then you'll need a higher gear ratio because the larger tire will take longer to rotate. So the more teeth you have, the faster your tranny will rotate the rear tires & that results in faster speeds - especially at take off. Try putting in 4.10's on stock/ factory rims and tires and there will be a HUGE increase in terms of take off

Gears are def a great addition to our stangs and a great buy in terms of performance ~ J

Gene K

My point was in a car (such as yours) actually capable of less than 160 mph its academic.
It can only "limit" top end if the car can get there.

In your example using the 3.55 instead of 2.29's "limits" top end.

Bluestar

3.31 Gears
3.55 Gears
3.73 Gears
4.10 Gears Any Questions[/align][/align]

MIKE562

Haha thatsgood way to put it Bluestar