Need advice: z3m rear end. Keep or Sell?

[anassa]

Okay, so I am lucky enough to get my hands on a z3m shell - has everything including the z3m rear.

Maybe because I have not been in the bmw scene long enough but how worth while is the z3m rear end? (other then OMG ///M Powwaa!! =) ) I know the benefits like larger bearings, vented rear, stronger etc.

Problem is that I don't see much of a problem with our rear end, and its braking power. I am not a track guy (yet at least) When I use my brakes the most its on a deserted canyon road, but its always night and the road and air tends to be cooler and I got SS brake lines all around, super blue, good pads etc, I haven't had any problems with brake fade or the need for bigger rear brakes.

As for more power I am likely going to keep the M44 for a good while (why replace it if it runs fine?) I definitely will go more power in form of FI or 6pot but that will be a good time away, 1+ year ish. Also people run ti subframe/trailing arms/subframe etc with S52 without much problem it seems.

I could use the money from selling it too, I am assuming it would sell for 1k ish??

Also I am wondering how much heavier it would be then stock.

Finally: Is it rare enough / valuable enough that I should keep it??

Need some input from you guys!

[erikerikerik]

The rare part on that Z3M comes from 2 parts, both of them are(are part of) the LSD.
part #1 the Super finned rear cover. That part you can sell in the blink of an eye.
part #2 Is, is it a torsion style or clutch style?

[anassa]

right, the finned cover is definitely a wanted item, as for the actual diff I'm pretty sure its just a 3.23 clutch diff

But then I guess the question I really have is, does anyone have personal experience, and has had the finned cover and found it useful compared to the regular, especially if they have a torsion diff already.

Same with the complete z3m rear. Is there anyone who has had the z3m and had the chance to drive with it before and after and if they felt it was worth it, or passed it up but now wish they got it?

[pdxmotorhead]

The primary benefit of the finned rear cover is cooling the internal parts so they last longer especially the limited slip unit. If it was me I'd swap in the whole rear suspension unit as a system.. Its theoretically a bolt in deal.. have camber adjusters welded in before the install and youve got a sweet upgrade.

Dave

[anassa]

Right, it would be awsome.

But again my question is still along the same lines, I can use the money from selling it, and is it worth it if I don't use it. If my rear end is perfectly functional why replace with bigger/better if it won't be used and just end up weighing it down more. Example, having a m44 and putting some huge porsche brakes up front when some simple vented e36 brakes with good pads/rotors ss lines, fluid, will result in the same effective braking. Not only that having those huge porsche brakes might actually result in poor braking with all that extra rotating mass.

But I don't know for sure, thats why I am still asking, is it effective/practical if the car won't see continual track duty and be over 240hp.

The finned diff is definitely something I wouldnt mind retaining though, but I have around the same question with that, will daily driving and some rigorous driving inbetween really heat up the internals and LSD unit in a way that the extra cooling from the fins are actually necessary, or will it be more of a accessory?

(besides I will be running a torsion type LSD diff which as far as I have heard doesn't heat up as much as the clutch type - true??)

[erikerikerik]

The fins do help, however if your going to go ahead and do some "rigorous driving" you might as well go the extra step to add a cooling loop active or passive. like *here*

[anassa]

What I'm trying to do is take out any unnecessary steps, and adding that I think would be quite unnecessary as I am only finding out if the extra cooling from the fins are even worth it in the first place.

(And seriously $600+, i can't pull that out of no where, and I could probably spend that elsewhere more effectively.)

As for the brakes I found a very informative thread that seems to give me the answer to the use of the rear z3m brake setup:

http://www.318ti.org/forum/showthread.php?t=32902

Its a good read.

Seems like for what I use the car for, just regular vented e36 brakes upfront and stock rear with good pads/fluid will be all I need.