2.93 to a 3.73 diff

SuperEta325 · #1 (**permalink**) 08-31-2003, 12:48 PM

I own a 5 spd 1986 325eS and it currently has the 2.93 differential in it and i am thinking of upgrading to a 3.73 out of a 1988 325iS ( the "IT").

However since my cars redline is 5,200 max redline (Dinan Chipped) wont the first gear be short and will it be a problem for me when i am driving.

Has anyone done this and if so i would LOVE to hear your comments and how you like having a 3.73 in your Eta.

-Ryan
I want to do this because i hear the 2.93 is pure shit. lol

Plus i see no reason not to upgrade since i have a 3.73 sitting in my parts car.

SuperEta325 · #2 (**permalink**) 08-31-2003, 06:38 PM

WoW i guess i will be the first to do this as no one seems to be making any comments on it.

ROCK ON!!!!!!

-Ryan
I guess i'd better getting swapping so i can be the first to do this. LOLOLOL

Alan e30 · #3 (**permalink**) 08-31-2003, 07:00 PM

cant find my manual with the gear ratios in it. here is the equation you need to figure your speed. not sure about the 336 constant, got it from a website. gear ratio is
trans gear ratio * rear end gear ratio.

MPH = (rpm x tire diameter) / ( gear ratio x 336)

runetang · #4 (**permalink**) 08-31-2003, 07:40 PM

wow, your car wouldnt be able to hit a high top speed at all, like 120mph TOPS.. redlining..

but in the 1/4 mile for what it is, a modded 325e with a drastic gear change like that, it would perform DAMN good.

I mean, i bet you could get the drop on a stock e30 325i and maybe take him by a little in the 1/4 mile, but you'r cruising rpms are going to be very high, and youll get worse gas mileage.

basicly itll be a rocket from stoplight to stoplight, at the expense of more gas, high cruising revs, and a low top speed.

runetang · #5 (**permalink**) 08-31-2003, 07:42 PM

or in other words, it would be an unsuspecting car to give beatdowns to guys in civics without motor swaps and all the v6 american cars that just love to drag race .. but not the newer v8s. :P