ORIGINAL: thejollypostman

can you guys explain why i would want to change the differential and get new gears. Do i really need to be able to turn faster? why is this a common mod.

ORIGINAL: Novanutcase

LOL! I think you misunderstood me! When you go to a higher gear ratio your rear wheels will turn faster, quicker. You don't get any HP boost you just get quicker.

Think of it this way! When you are riding a ten speed bike if you change to a higher gear but keep pedaling at the same rate what will happen? You'll go faster! Same thing with higher ratio gears.

John

ORIGINAL: tbirdscwd

Its kinda the opposite. The stock gears in your mustang's differential should be 3.27 to 1. That means, for every 3.27 times your driveshaft turns, you wheels turn once. These ratios from the factory are designed more for gas mileage and economy than for performance. Changing this ratio to 3.73 or 4.10 to 1 (the two most common gear changes in our cars) allows your car to accelerate faster because it is easier for you engine to turn those gears. It will also get you into the higher rpms faster (where your engine makes more power)

A bike is a great way to put it, just wasn't explained the right way. Imagine putting your ten speed in the highest gear and trying to accelerate quickly from a stop. Its gonna be sluggish. If you downshift, you be able to accelerate faster because its easier for you legs to get the lower gear spinning faster.

You might think this will affect your top speed, but 4.10 gears will get you to over 150 in 5th so unless you plan on faster than that, you'll be ok.

ORIGINAL: thejollypostman

so if i swap the hpipe what kind of exhaust should i get. Would magnaflows create a good combination. I dont want to do flowmasters it seems everyone does that. I want a really deep sound.