Not much to really say here but I have zero mods on my car, I have only had it a month now, don't really see me doing much to it mechanically expect air filter switch. But I was on I-277 the other night and had a Mitsu Diamante or Galant, older model probably 1998 riding my bumper and he pulls up besides me and starts toying with me so I dropped it into third (my sweet spot) and away I go. It felt very good. I got up to about 95 and had to drop it down or get a ticket I figured. What a rush regardless. Then last night I got my second chance to race my friend who has a 2001 Buick Regal (grandpa's car). I stayed with it and we got up to about 70 in a 35 zone so we had to back off but he never got a full car length away and I never saw his tail lights. Not a kill, but pretty good considering I am giving him more hp and torque (184hp vs. 200hp) and (175lbs vs. 225lbs). From my experience people underestimate the 325i and associate it with a civic style performance car. I don't mind though, just gives me the oppurtunity to show them what German engineering can do for you.

if ur 5spd, a 3.46 diff will make ur car feel alive :D

good kills

I am a 5-spd. What does something like that cost? I am really a novice, I have been reading a bunch. What kind of hp gain or torque gain? And explain what it is?

I am a 5-spd. What does something like that cost? I am really a novice, I have been reading a bunch. What kind of hp gain or torque gain? And explain what it is?

a search on E46Fanatics could be your best bet.

Its basically the rear end gearing of the car. power travels down driveshaft, through the differential, and to the output flanges and the rear wheels. we are 3.15 stock, and the 3.46 is the diff out of a 325 323 or 328 automatic. you can expect ~9% better torque to the wheels.

Its a great mod, give a little search and see for urself, many testimonials :D

Cool, I just looked it up and yeah, seems like a great modification for around $400 material cost. What are the labor cost's you think? I like keeping the mods around $500 or less and so does my wife and kids :). Anything to get the same 9% in hp?

Follow up, I did do some more reading and it appears that RPM's could be an issue. So if I install the 3.46 I will have higher RPM's? I am thinking higher, constant, RPM's aren't good for the motor over the long haul. Right?

Follow up, I did do some more reading and it appears that RPM's could be an issue. So if I install the 3.46 I will have higher RPM's? I am thinking higher, constant, RPM's aren't good for the motor over the long haul. Right?
Nice kill and runs.
I'm not sure how you drive your car or how long you plan on owning it for, but I wouldn't worry about that. These german cars are so impressive with the amount of power they can handle, especially for long periods of time. Being your manual getting the "poor mans supercharger" is definitely the way to go. Your gunna feel that 9% increase of torque more than you know.

Also you asked about 9% more hp I believe. Well I dont know about 9% but getting your car sharked which is reasonably cheap, $350, will give you more throttle response, maybe 10 more hp "as it claims" and more torque. It will also bring the revs up alittle higher so when you go WOT(wide open throttle) just in case you didn't know, you'll get more feel out of the car. Also with the shark you have the ability in a very easy method to install it yourself and uninstall it whenever you want. So very convienant!!!

Anyway with 3.46 alone being your manual but also sharking your car you'll have a peppy little 325i. Nothing fast but definitely peppy. Anyway just my .02!!! Goodluck on whatever you decide to do, and once again our cars can handle trust me. I've driven my car like crap for almost two years now i mean gunning it at almost every light and going WOT all the time. Plus I have a bunch of aftermarket products and my car has only had one problem. Two of the ignition coils broke so I was running on four cylinders but I'm starting to believe that is a notorious problem in general for BMW's because it has happened to other people I know. That problem by the way was fixed by the BMW dealership I go to in no more than an hour, god I love being under warranty!!!!!

Also the install on the 3.46 gears shouldn't run you more than $150-$200. I would think though if either you have connections like a friend or can simply talk to someone the price will go down.

changing the rear end as others have discussed is awesome :buttrock

I changed the rear end of my car (540) and the difference was bigger then any software or other mods i had done to my previous car (325is).

Do it, you won't regret it.

Nice kill/death and what color is your new 325i? Where is a good reliable site to buy 3.46 diff?

E46fanatics!!!!!!

The color is Black, I am from Charlotte, NC and it is going to rain but soon after it stops I won't to post some pics. I got another kill going home tonight from work, here lately, seems like I have had a lot of opps. This time it was an Acura RSX looked like an 02 or 01 (new body style) two door. He took off at a light and gunned it then I just sat back and followed him to the next light where he tried it again but this time I was all over it and didn't leave him in the dust but definetly kept him at bay and in the rear view. He just smiled as we came to the next light where he turned right. So far I am loving it!

Also, what kind of RPM's will I be at just cruising along at like 75 mph if I do the diff swap out to the 3.46

RPM may be an issue for you. if your change ur oil a little sooner each time, u shouldnt have long term concerns.

at 80mph, i used to cruise at about 3,400rpm. now i cruise at 3,750, an increase of 350rpm.

if high RPM are a concern, you could use the 3.38 rear end out of a 330i/ci steptronic, but it will require slightly more work, as you have to swap out the flanges and use the existing ones off your 325 diff. gains will be a little less, but still noticable.

they dont call it the poor man's supercharger for nothin :D as others will attest

That doesn't sound like a lot of noticable rpms. Can you even hear that difference? Also I had planned on changing the oil (synthetic) every 5000 miles. Will this cover it?