E46 Final drive ratio

[flashinthepan]

Would'nt it be a fairly efficient way to improve 0-60 times by putting in a higher rear-end ratio ??, Has anyone done this swap.

I noticed the 6-sp 330's have a 2.93 drive ratio vs 3.07 for the ZHP.

I know the cams are modified and the computer tunning etc...on the ZHP, but for the regular E46's...would a higher gear ratio result in an improved 0-60.

And worse gas mileage most likely.

Anyone ever do this swap ?????

 

[PuShAkOv]

Not everyone here is technically-edged...

what does "6-sp 330's have a 2.93 drive ratio vs 3.07 for the ZHP" mean?

can you put what you said in everyday terms?

 

[flashinthepan]

Hi Push,


I am curiously wondering if the 2.93 rear-end gearing in the stock 330ci's

can be swapped to a 3.07 gearing....and if so would this provide much in the way of increased

performance ??.


I noticed the ZHP's come with the 3.07 ( amongst other performance mods).

has anyone put a modestly higher rear-end gear in thier Bimmer ? and if so...any results ??

Thanks !!

 

[98r-1144]

While I am not familiar with the compatibility of swaps, I CAN tell you how gearing will affect the performance.

While I drive my E46 323i as the commuter, I have an Integra Type-R that is my fun car. I have changed the final drive ratio on my Integra from a 4.4 to a 4.785. Honestly that has been the mod that has made driving the car much more fun. I can pass cars with ease in the highest gear (5) on freeways (and I have a 1.8L!).

By lowering (numerically higher) the final drive, you will be able to put more available torque to the ground in each gear (since the final drive affects all the gears). That does not mean you will get more torque showing up at the local dyno... it's kind of hard to explain... Actual torque that is put to the ground is calculated something like (ft/lbs) x gear ratio x final drive ratio. So any increase in any of those numbers will provide more actual torque put to the ground.

By lowering the final drive, you affectively reduce the top speed in each gear (for all the gears). Your RPMs will be higher at all speeds than it was before (may decrease gas mileage). If you are putting out a lot of power, the final drive upgrade can cause you to lose more traction in 1st (and maybe 2nd) gear.

Your 0-60 time may or may not decrease, depending on traction. You may also have to put in an extra shift, which will add time (My Integra originally went to ~63mph in 2nd gear on the original final drive. After the new final drive, I have to shift to 3rd to hit 60mph).

Most people do this upgrade for road racing and autocrossing purposes. I am not familiar how straight line acceleration will benefit, but I assume it would, since you are going thru the gears a lot quicker?

I say do it... it is so much more fun

 

[MrElussive]

If you do this swap, you will lose maximum speed in each gear, but you will have more power throughout all the gears. I say do it, if you race a lot. There is nothing better than keeping your engine rpm's in in the power-band more easily with a closer-ratio transmission. But driving on the street may require more shifting, which may be more annoying for you.

 

[bahnstormer]

for the E34's i know a lotta people use the 525's gears on the 535i for better off the line punch and low end. i'll eventually do the swap on my car

you get higher rpm's on the highway and more noise, but much faster 1,2,3 gears