Gear Differential

[pamato]

What is the stock gear differential for a sport 540i, 6 speed MT?

What are the advantages of changing the gear ratio? I am a newbie to cars, so forgive my basic questions.

Thanks,
Paul

[SehrSchnell]

Originally posted by pamato@Nov 22 2004, 01:35 PM
What is the stock gear differential for a sport 540i, 6 speed MT?

What are the advantages of changing the gear ratio? I am a newbie to cars, so forgive my basic questions.

Thanks,
Paul

[snapback]235373[/snapback]

I believe the stock ratio is 3.15 if it's a sport. You will notice a great difference in acceleration by changing the gears, however, your high end will suffer with lower gears.

I switched to a 3.91 LSD in mine, from a 3.46 stock. A lot quick off the line, but higher rpm's on the highway, which also means worse gas mileage.

I think the 3.15 in a 6 speed 540 is perfect.

[pamato]

Originally posted by SehrSchnell+Nov 22 2004, 07:33 PM--><div class='quotetop'>QUOTE(SehrSchnell @ Nov 22 2004, 07:33 PM)</div><div class='quotemain'><!--QuoteBegin-pamato@Nov 22 2004, 01:35 PM
What is the stock gear differential for a sport 540i, 6 speed MT?

What are the advantages of changing the gear ratio?* I am a newbie to cars, so forgive my basic questions.

Thanks,
Paul

[snapback]235373[/snapback]

I believe the stock ratio is 3.15 if it's a sport. You will notice a great difference in acceleration by changing the gears, however, your high end will suffer with lower gears.

I switched to a 3.91 LSD in mine, from a 3.46 stock. A lot quick off the line, but higher rpm's on the highway, which also means worse gas mileage.

I think the 3.15 in a 6 speed 540 is perfect.

[snapback]235557[/snapback]

[/b][/quote]

I was checking out the Dinan web page and they claim all sport models have the 3.15 gear differential, but not LSD.

What is the difference between the stock differential and the LSD?

Paul

[pamato]

Originally posted by pamato+Nov 23 2004, 08:33 AM--><div class='quotetop'>QUOTE(pamato @ Nov 23 2004, 08:33 AM)</div><div class='quotemain'>

I believe the stock ratio is 3.15 if it's a sport. You will notice a great difference in acceleration by changing the gears, however, your high end will suffer with lower gears.

I switched to a 3.91 LSD in mine, from a 3.46 stock. A lot quick off the line, but higher rpm's on the highway, which also means worse gas mileage.

I think the 3.15 in a 6 speed 540 is perfect.

[snapback]235557[/snapback]

I was checking out the Dinan web page and they claim all sport models have the 3.15 gear differential, but not LSD.

What is the difference between the stock differential and the LSD?

Paul

[snapback]235894[/snapback]

[/b][/quote]


I spoke to BMW on the phone:

1st gear is 4.23:1
2nd gear is 2.53:1
3rd gear is 1.67:1
4th gear is 1.23:1
5th gear is 1.0:1
6th gear is .83:1
Reverse: 3.75:1
overall: 2.81:1