Adding 3.46 Diff To 2004 330ci

[Ohrid]

hey guys, my car only has 1,000km on it soo far. (had it for 2 weeks)..and i soo couldn't be stuffed waiting for another 2 weeks or so, to rack up the first 2,000km needed, in order to 'try' out the car..so.. as soon as i had 999km on the odo reading...WAPPISH...to 6,000rpm 1st and second gear. damn it felt good.
but lately i been reading about diffs. and i heard that they increase acceleration, but reduce top speed, do to the increased diff ratio (3.46 compared ot the stock 2.93).
my questions are these:
(1) is it too soon to take out my stock diff and put in a 3.46?
(2) will the 3.46 diff, give me that intertia pull back feeling, similar to a WRX? at least in the 1st or even 2nd gear?
(3) my 1/4 mile time, should i expect a low 14seconds?

[woobiee]

i think its a bit too soon to rip it out. unless you are buying a brand new 3.46.

many 330 owners usually get the 3.38 diff rather the 3.46 since its too aggressive.

you will def need to shift to 3rd gear to reach 60mph with a 3.46.

yes a 2.93 to a 3.46 will def increase your torque and acceleration numbers PER GEAR! This does not necessary mean your 0-60 will be better.

This also applies to quarter mile times. It could or could not be better. Look for RPM/gearing calculators to find out your raw numbers (this does not include physical elements like friction or wind resistant)

[Gulelin]

Yea, i'd go 3.38. And even then only if you went with the stick

[Ohrid]

yeh, i understand, that i will need to shift gears much sooner, and the speed attainable in each gear will be decreased. however, i am mainly interested in, cruising around 40mph, and then mash the throttle, just to feel the force pin me back in the seat.
will that force be similar to WRX style wammmm?

[MrM3]

Originally posted by Ohrid@Nov 8 2004, 05:47 PM
yeh, i understand, that i will need to shift gears much sooner, and the speed attainable in each gear will be decreased. however, i am mainly interested in, cruising around 40mph, and then mash the throttle, just to feel the force pin me back in the seat.
will that force be similar to WRX style wammmm?

[snapback]226988[/snapback]

the amount of power you put to the wheels is still dependent on your engine speed; therefore, shorter gearing will not always give you the mechanical advantage your looking for. in your case, with the stock 2.93 diff your probably around 4000rpm @ 40mph in second gear, with a 3.46 diff you will be around 4700rpm @ 40mph in second. this will give you a noticeable increase in response and acceleration in second, but the 2.93 will still pull noticeably harder in second gear @40mph than the 3.46 will in 3rd (~3100rpm @40mph). by making the switch from 2.93 to 3.46 the car will still pull just as hard as it used to, only at different speeds.