ok im looking into purchasing some new rear gears for my Z and I was curious of which gears would give my car more power output?

 

Nether one will give the car more power. What you really want to know is the amount of torque delivered to the drive wheels. The 4.11:1 gears will multiply the available torque by 4.11 times, while the 3.73:1 gears will multiply the available torque by 3.73 times. All things being equal, the lower gears (4.11 being lower than 3.73) will allow the car to accelerate quicker, up to a point, but you also have to keep in mind that the lower the gears the higher the engine must rev to to maintain the same road speed.

 

And the greater chance you have of breaking your rear end with a hard launch! Yay!

 

How do you figure that?

 

These 7.625" diffs are weak. There's some forums where guys with a v6 and 4.10s blow the diff apart.

 

Well more torque to the rear wheels with a weak rear = easier to be blown...if people can blow them on stock power, then...

 

Ah, but you said you'll break the rearend, that's why I asked to see what you meant. Getting a car moving with a higher rear gear, say a 2:73, puts more stress on the engine, trans, driveshaft, and ring & pinion. Lower gears, say a 4:11, lowers the stress on those components, which is why the engine and drivetrain now have a much easier time at getting the car to jump out of the hole. But, since lower gears act as a torque multiplier (after the ring & pinion), more stress would be put on the axle shafts. The entire rearend isn't in jeopardy, just the axles if they can't take the torque.

 

Are you going to street the car or is it strictly for drag purposes? If it's your daily driver I would say 3:73's

 

imma street it mostly and occasionally take it to the track its always fun to track a car and see what its true potential is

 

I would go with 3:73's then.