Bmw 325ti, a number of queries

[josh-cg608]

Hi all, i have a 6 speed 325ti which now has been converted to 330ti. Have a few questions in some upgrades ill be doing any help greatly appreciated..

Car will mainly be road use if it does do a trackday it wont be a regular occurance.

1. Brakes

330i front brake conversion. Is this worth it? Also what is actually needed for the conversion? Calipers obvs then carriers i presume. Do these just bolt on from a 330i?

Or im thinking to just put new standard 325ti calipers on with yellowstuff pads

2. Braided lines.

Do these warrant the money? Or shall i just leave the original ones on.

3. Bushes

Again do people reccomend polybushes? After B a bit of a stiffer ride and feel on steering

Or do i just go genuine bmw.

4. Diff

My diff is leaking so will be getting it rebuilt.

Will it warrnt a lsd? Are they worth the money or be a waste on this project.
Have people put lsd on 325ti if so how does it improve the experience.

As i said any help greatly appreciated

[Krikkit]

For me:

1) I wouldn't be that bothered, but my driving style isn't particularly hard on brakes, new higher-performance pads and fluid suit me fine.
2) Yes, imho
3) General concensus seems to be polybush the diff carrier, everything else fit standard. On the rear end you can fit the M3 spherical bushes rather than the standard metallastic ones which give a nice increase in stiffness. You'll also want to change the steering coupling on the column with a new one, or a solid one.
4) Seems rude not to if budget allows, for me it's out of reach at the moment but it's a mod I would absolutely do.

[1602Mark]

Hawk blue pads were enough of an upgrade for me, with new discs.

LSD from Gripper (or an E46 M3 item?) worthwhile.

Bilsteins and lowered springs or KW coilovers.

[helix402]

You can fit M3 trailing arm to body bushes.

[josh-cg608]

Amazing thanks all for your replies, ive recently replaced all shocks for just standard msport shocks and eibach springs in happy with that set up atm. Ill just stick with updrated pads on the standard brakes then saved the hassle.

[zek]

I recommend poly in the front control arms, rear trailing arms, subframe and diff, everything else OEM.

[BFleming]

My experience says to use OEM in the rear trailing arms. They don't just rotate in one plane, so the slightly softer rubber of the OEM bushes is a better option. Go polybush and it'll crucify the other suspension joints pretty quickly.

[helix402]

BFleming said:

My experience says to use OEM in the rear trailing arms. They don't just rotate in one plane, so the slightly softer rubber of the OEM bushes is a better option. Go polybush and it'll crucify the other suspension joints pretty quickly.

I agree with this, the M3 bushes are a slight upgrade.

[Krikkit]

helix402 said:

BFleming said:

My experience says to use OEM in the rear trailing arms. They don't just rotate in one plane, so the slightly softer rubber of the OEM bushes is a better option. Go polybush and it'll crucify the other suspension joints pretty quickly.

I agree with this, the M3 bushes are a slight upgrade.

That's my understanding as well - hence polybushes on the rear diff cradle etc that aren't moving are the best option, but the spherical joints from the M3 are the best compromise on the trailing arms etc.

Not specific to BMW, but it echoes my experience of polybushes in other cars too.

[josh-cg608]

Thanks for all your help, been in touch with my parts guy at bmw. Just confirming that the e46 m3 rear trailing arm bushes are a direct replacement to standard bushes in original arms?

[helix402]

josh-cg608 said:

Thanks for all your help, been in touch with my parts guy at bmw. Just confirming that the e46 m3 rear trailing arm bushes are a direct replacement to standard bushes in original arms?

They are in the non Compact, should be in the Compact too. Easy way to check is to see if the non M saloon/touring standard bushes are shared with the compact.

[Krikkit]

It was a while ago I put this together, but I believe the bushes you're after are 33306852895 and 33326770817 for the M3 ones.

https://www.realoem.com/bmw/enUS/showparts?id=BL92...

1. 2, 3 and 4 on this diagram. I believe they're a straight fit to the standard arms etc, as they only changed the bushes not the castings.

[helix402]

Krikkit said:

It was a while ago I put this together, but I believe the bushes you're after are 33306852895 and 33326770817 for the M3 ones.

https://www.realoem.com/bmw/enUS/showparts?id=BL92...

1. 2, 3 and 4 on this diagram. I believe they're a straight fit to the standard arms etc, as they only changed the bushes not the castings.

Spot on, 4x895s 2x817s.

[zek]

Krikkit said:

That's my understanding as well - hence polybushes on the rear diff cradle etc that aren't moving are the best option, but the spherical joints from the M3 are the best compromise on the trailing arms etc.

Not specific to BMW, but it echoes my experience of polybushes in other cars too.

Looking at the subject which has been well documented on forums etc I think it's subjective - I personally have not noticed any downsides in 35k. The M3 bushings + limiters I ran previously did not inspire the same confidence or provide as much feedback.

My car has full CSL suspension / spherical joints / LSD etc so perhaps this setup lends itself more to a stiffer bushing.

In my 330ci I have OEM rubber all round as I didn't want to compromise comfort at all.