[330iCanada]

If I upgrade my final drive from 2.93 to 3.38 am I increasing the max torque applied to the ground (by 15%) or just decreasing the time it takes (by 15%) to apply the max torque to the ground?

With a 15% change in gearing will I see a 15% decrease in 0-60 sec? Torque is directly proportional to acceleration.

 

[330iCanada]

To add to the above. I understand that horsepower = torque * RPM/5252. That is why I think that the gearing just changes the time it takes to reach max torque.

 

[poncho]

If I upgrade my final drive from 2.93 to 3.38 am I increasing the max torque applied to the ground (by 15%) or just decreasing the time it takes (by 15%) to apply the max torque to the ground?

The applied torque is increased by 15.3%.

 

[MarvelPhx]

There is an inherent problem with thinking that simply changing your final drive to shorter gears will make the car quicker. It really depends...

If you shorten it up too far, you are not going to be staying in the power band very long (which we are lucky enough to have a lot of from BMW), AND you will spend more time shifting. Since shifting can take up to .5 seconds (for slow shifters), you can easily lose that in 0-60 just by having to hit 3rd.

Also, you will run higher RPMs at a given speed, so the fuel economy drops along with dropping your top-end speed.

 

[Nick325xiT 5spd]

Those of us who can't reach 60 in 2nd ANYWAY would LOVE lower gearing. The other question is whether or not you car about your 0-60 time, or the car's overall acceleration. My car is a LOT peppier with my autox wheel/tire combo on. (Effective 3.43 FD.)

 

[330iCanada]

The beauty of the new 6 speed manual tranny solves all the issues you mentioned MarvelPhx.

 

[MarvelPhx]

That I agree...

I was only stating that there is a "too far"... and to measure the benefits of going to shorter and short gears...

 

[Shortshift]

Could someone elaberate a little more on the gearing and the new 6-speed ... ?

Can u reach 60 in second .. ?