Need your input on how I should build a 3.0 for my xi

I have just been offered a m54 that has 130k but it is in pieces (PO was gonna do a full rebuild) so my question to you guys is what are some worthwhile mods to do while it's in pieces. For example cam swap, injector swap, exhaust manifold, etc.

Let the discussion begin!!

Also this motor will be going into my 2001 325xi 5spd wagon.

I wouldn't do anything except for putting headers on it.

The engine is great as it is, just put it back together.

Make sure you replace items such as the rear main seal, all gaskets, and any hard to reach sensors.

Really? No cool swaps like with my m50 (s52 cams, 24# injectors & a chip)

I'm planning to rebuild the thing (short block & some head work) so I'd have a fresh power plant.

There's not many bolt on made for the M54 unfortunately (would be a good time to turbo/supercharge with the motor out of the car though!). While the motor is out, I would definitely clean and paint/powdercoat everything, replace all seals, install a Stewart water pump, and call it a day.

Dude dont tempt me with boost, I've got a fresh precision turbo 6262 sitting on my night stand in the bedroom haha

Well alright then looks like I'm just gonna do a standard rebuild, who makes a good tune for this motor?

Will I need to swap any other parts with it besides the ecu?

What about sticking a set of S54 ITB's on there??

Originally Posted by Eurofreak13

Dude dont tempt me with boost, I've got a fresh precision turbo 6262 sitting on my night stand in the bedroom haha

Well alright then looks like I'm just gonna do a standard rebuild, who makes a good tune for this motor?

Will I need to swap any other parts with it besides the ecu?

There's no really good tune for it either. BMW did a great job of milking the motor for everything they could get out of it. Just replace the wear components and put it back together.

If you are going from the 2.5L to the 3L, you will need a new/different MAF, intake manifold, intake runner, throttle body, and obviously the ECU. There might be other sensors that are different too.

Originally Posted by Eurofreak13

What about sticking a set of S54 ITB's on there??

The S54 has 6 throttle bodies. The M54 has one and there's no way to install 6 as the ECU can only control one of them.

The m54 is complete with accessories, harness & ecu.

I was just wondering if its possible to mate the ITBs on the head & possibly using a flash or custom software for it but I may be getting a little ahead of myself.

atleast you'll have a "330xit"!!, Interested to see the outcome of your build

Originally Posted by Eurofreak13

The m54 is complete with accessories, harness & ecu.

I was just wondering if its possible to mate the ITBs on the head & possibly using a flash or custom software for it but I may be getting a little ahead of myself.

Anything is possible with the right amount of cash, but I'm not sure it would give you any advantage whatsoever.

Just put the beast back together and save up for a supercharger...and a 323i badge.

I don't like SC, I hate that damn whine!! I'm thinking a refresh & keeping it NA is best for a daily driven car. Would like to do the standard bolt on stuff. Who's exhaust system stuff (headers mainly) has been proven to provide the best power gains? I'm definitely dumping the cats but will need a good cat back system.

Also I noticed some other member mentioning a big bore throttle body, what company is boring these guys out & which housing is the correct one to use? I'm assuming its the m54's throttle body. Plus they were talking about dyno tuning with the addition of cams. Anyone know of a good company to contact on the west coast? Possibly the PNW?

The E46 systems don't whine all that much and the centrifugal designed SC systems don't whine at all. The typical SC whine is that of the screw (roots) compressor spinning.

Anyway, Any header system will behave exactly the same. None of them give you any more power than any other. Bimmerbrakes headers tend to be of higher quality and fitment but you can buy eBay versions for cheaper.

The stock exhaust is actually very good and unless you want something else for the sound, just leave it on there. You can delete the resonator if you want more sound.

Cams will add ~10hp for $500-600 and a lot of work. Not worth it, IMO.

Larger throttle body nets something like ~5hp maybe for a lot of money. Remember that the intake inlet is only so big so having a giant TB really doesn't help all that much unless you want to make a new intake manifold.

One of the best things you can do is shed weight. That's free power and you can sell parts and make some money on them. Start with lightweight wheels and tires, then grab a Mini Cooper battery for ~20lb weight savings.

There is a thread on here about getting the most NA power out of this engine. If I remember correctly, he spent a butt load and didn't get a whole lot for his efforts.

Edit: Here you go
http://forum.e46fanatics.com/showthread.php?t=736943

Random question, if I were to use a LTW flywheel how light is too light? 10lbs?

Originally Posted by Eurofreak13

Random question, if I were to use a LTW flywheel how light is too light? 10lbs?

If you don't deal with heavy traffic then go for it.

I would red loctite+wire the oil pump nut (especially if you go with a LWFW), replace the pan gasket and install a new starter.

Why wire the oil pump bolt & replace the starter?

It's more notorious on the b30 when you rev above 6k rpm, the nut vibrates itself loose followed by the oil pump sprocket coming off and causing a total loss of oil pressure. A LW flywheel only makes it worse. If you spend a lot of time on the redline, the oil pump nut should be adressed.

The starter is one of the hardest thigs to replace on the xi. I'd just replace it and never worry again.

Just my opinion, not saying that these have to be adressed.

Awesome, thanks for the info! Yeah I spotted the starter last night & have visions of busted knuckles & cursing up a storm haha

I read some builders were stuffing "Z4" cams in these babies? ECU flash was not needed. Take this over to the General forum and ask about the Z cam. Quite a few were doing it so there must be some benefit? Headers take away from the low end where unless you're taching that bad boy, you trade low-end grunt for high rev ponies. Torque wins races, HP is just a number. Bang for the buck, there's little to gain unless you go all out - forced induction.