Now then, Ive got a 2000 E46 323 coupe and I'm currently running a manual 323 welded diff. Im looking to change it for something else as its not as good (doesnt spin up the wheels as easy, a lot of clutch kicking mid corner) as I was expecting. I know the 323 isnt an ideal starter as they are down on power compared to 325/328/330 etc and relatively heavy compared to E36 and other cars with similar power. Anyway, with this in mind, I was told to get a 318 diff welded and install that. I've found that if I do this I will need to also install the rear portion of the prop and the half shafts to enable it to work. My questions are: 1. If I do this im concerned the shafts will fail before anything else as they are smaller/weaker than the 323 ones. How likely is this? 2. Does an auto 323 diff use the same shafts and prop as a manual one? The difference in ratio is more favourable with the auto 323 one over the manual 318 one as far as i am aware... Manual 323 = 3.07 Manual 318 = 3.38 Auto 323 = 3.46. 3. Ive read about 4.44 diffs. All I can find reference to is E36, is it worth trying to find one with this ratio for my E46 or are they 36 only? Any help on this is appreciated, first car I've built so still finding my feet with a lot of it all. Cheers
You can get a 4.44 for a e46 but they arent he best as it makes the gearbox ratios a bit shit. When you weld a diff youll snap shafts regardless, just bolt the small diff in and get some spare shafts. Also if you're down on power, run higher pressure in your tyres. People get on drifting mx5s all day and they are low on power.
Ive snapped 2 shafts within 24 hours of my car being on the road. 1.8 diff and shafts. since then ive fit 325 cups and shafts hopefully the issue has now went away
Running 50psi in the rears atm, not sure how much I dare put in them tbh. The reason for wanting to know about the auto box was because of the ratio it gives, and to save having to swap prop n shafts etc. Also it'd be a pain to have to replace a broken shaft at an event expecially as the 323/325 ones are plenty for standard power. Can I just swap the cups off the car on to the new parts to make it work with the smaller diff?
I'm currently running a E46 328i welded diff in my 328 compact conversion, I think the ratio is 2.93 and it locks up perfectly.
