S54 swap into 01 Z3 Coupe 3.0

**RacerXTreme7** · 09-02-2011, 12:22 PM

As the title suggest, I'm looking for info in dropping a S54 into my 01 Z3 Coupe 3.0. I have the opportunity of getting a S54 from an M3 and after searching, it doesn't seem anyone has done the swap into the same chassis as mine (plenty of other swaps into different cars though) or at least no write ups about it.

Now, before you facepalm or give "It isn't worth it.", "It'll de-value your coupe.", "Sell your coupe and buy an M.", and other feedback I already know and am NOT asking for, save it please

. I have questions and am looking for factual answers and NOT anyone's opinion though everyone is entitled to them, I'm just asking for facts about the swap, not is it worth it. A search yielded a bunch of the above "advice" rather than any real info on actual swapping on other forums, but this one has an actual swap section (SHAWEET!).

The appeal of 100 more hp naturally aspirated is what is drawing me to the S54. I've done the turbo thing before (I was a Garrett dealer at one point) and am just not looking to go the forced induction route if I don't have to. And it doesn't look like much can be squeezed from the M54. Headers, full exhaust, cams, intake and it looks like guys are getting 230-ish at the wheels. Some are getting close to 300 at the crank after extensive head work, custom pistons and custom intake manifolds, but those engines have lost their streetability. All that exceeds the price of the S54 I am about to get by 2 fold.

If the swap is too difficult I'll go supercharger.

I have a 2001 Z3 3.0 Coupe with only 68K. I also have a chance to purchase a S54 engine CHEAP. I don't know all it's history, but I believe it is from a M3, and it was salvaged from a fresh water flood. I will break the entire engine down and rebuild, fix, probably upgrade as I go along and plan on taking my time as my current coupe is still fresh and runs fantastically. I'd like to collect parts and rebuild the engine over a few years and be 100% ready for the swap when the time is right. For the purposes of this thread, lets assume it's a well built strong running engine ready to be dropped in. So, on to the questions.....

*Engine mounts.... will my M54 engine mounts work on the S54 or am I going to have to find S54 to Z3 specific mounts?

*What flywheel/clutch would I need to mate to my current trans? (I may get a 6 speed, after doing some searching, but lets assume I stick with the stock trans I currently have)

*Not worried about the rest of the exhaust system, but will a header from my M54 fit the S54? Header back will be fabbed, not wanting dual exhaust out the back, the dual to the rear muffler type system will be used, though aftermarket high flowing (haven't decided what to fab, not too worried about it yet.).

*Wiring, please tell me that BMW for the most part uses the same sensors for most of their engines and most sensors are in the same vicinity?? Will I be able to use the M54 harness, or will I have to find one specific for a S54? Please..... only the experienced here, I don't want anyone posting "Your going to need the ///M harness.." when they really don't know for a fact. I can't imagine the harnesses being that different, but that's why I am here asking. I don't mind extending a few wires or swapping connectors. The M54 has e-throttle and dual Vanos already.

*ECM. I realize they are completely different engines, but does BMW use the same basic ECM with engine specific tunes? Once the engine is wired up, can I flash and or tune what ECU I have to work with the S54? or.... will I need a specific S54 ECM? And if I do need a specific ECM, will it connect to the M54 harness? (I guess the answer to this will answers two questions).

Coil pack, VANOS, fuel injectors, and crank angle sensors all similar? (EX: coil packs have same resistance, VANOS and Crank position are same as M54 {hall-effect}?, same resistance on the fuel injectors {both engines have same high impedance or low impedance style injectors)?? Not concerned about wiring it up as I can change connectors, but if there are different sensor or driver types, that would need address either a different ECU or changing what on the engine (EX: changing injectors on the engine to match the ECU driver type etc.).

*Fuel system compatibility.....

Will the lines already inplace hook right up to the S54 rails (assuming I have the entire S54 fuel rail system intact)? (Are both systems returnless?)

*Engine accessories: Will the power steering, AC compressor, alternator transfer over from my M54 to the S54?

Any other hurdles I'm forgetting about?

THANKS!

~Mike....

**GGray** · 09-02-2011, 12:44 PM

Wow...

ahhh unfortunnatly the M54 harness will not work or ECU... You need the S54harness/ECU..

No one puts them in the Z3 because you can BUY an MZ3 with one already in it..

Not worth the trouble to do the swap. Sell the car buy an MZ3/S54 car...

**RacerXTreme7** · 09-04-2011, 01:28 PM

Wow and a thumbs down.... too much to read eh? Thanks for your technical and supportive response!

~Mike....

**AgentHubcap** · 09-04-2011, 01:45 PM

Have you looked for advice of people swapping the S54 into an E46? I think it is pretty much the same amount of work.

Are you looking to put in a new transmission, or just bolt it up to your 5-speed? The transmission swap would require a new drive shaft, rear subframe, diff, and half-shafts. You'd need different wheels, too.

**RacerXTreme7** · 09-04-2011, 02:13 PM

Originally Posted by AgentHubcap

Have you looked for advice of people swapping the S54 into an E46? I think it is pretty much the same amount of work.

Are you looking to put in a new transmission, or just bolt it up to your 5-speed? The transmission swap would require a new drive shaft, rear subframe, diff, and half-shafts. You'd need different wheels, too.

No, haven't thought about the E46 guys specifically yet. I'll take a peak on some E46 forums now though! I figured anyone who swapped in an S54 into anything would chime in here.

As for the trans swap, I've done some poking around on it, seems there's a particular model that is a bolt it, and there is one that requires custom drive shaft and shortening the shifter assembly. Not too concerned about it yet. I was just planning on dropping the S54 to my stock trans for now.

I'm still tossing the idea of the S54 swap around, I may just try and maximize what I have (M54) with headers, exhaust, cams, retune and utilize the output of those mods with a 6 speed trans and lower final drive. I have a feeling I'll get used to that power level quickly though lol. I suppose supercharging would be next, but being an engineer type.... power output from supercharging would be close to the S54 output naturally aspirated and that is what bugs me and why I like the idea of dropping an S54 in. As stated, the chassis was available with that engine already in it, which you would think would make for an easy swap since all the parts already exist for the swap. I'm just here trying to get a list of parts that I need to get, and find out what parts I don't necessarily need to get but can modify current parts to work.

~Mike....

**RacerXTreme7** · 09-10-2011, 12:45 PM

K, so far I need S54 to Z3 specific engine mounts, harness and ECU. Anyone know about engine accessories and their brackets being compatible with what I have on the M54?

~Mike....

**GGray** · 09-10-2011, 06:11 PM

REALLY

Everyone has basically told you do not to waste your time. But feel free to completely ignore the wealth of expierince here and attempt something that is not only ridiculous but compleltely not needed since you can BUY one for a lot less than trying to cobble it together..

You cannot just swap stuff around in a BMW like a Honda. BMW on the later cars has made it dam near impossible to "just swap it" like in the cars pre 1999....

I am doing an S54 swap into my E36 non sunroof track car...Guess what.. You literally have TWO options only... The Bimmerworld ECU/swap kit for $3300.00 or a stand alone programable ECU for about the same price...

Even better...

Contact Technique Tunning and buy a turbo kit.. Overall probably cheaper and will make more power...

And yes thats TWO thumbs down...

You need to listen if you ask for advice I suggest take it. Especially with what you are talking about. I have master BMW tech buddies who would not even attempt to do what you are JUST due to the amount of electronics involved...

**Robstah** · 09-10-2011, 06:33 PM

Originally Posted by GGray

REALLY

Everyone has basically told you do not to waste your time. But feel free to completely ignore the wealth of expierince here and attempt something that is not only ridiculous but compleltely not needed since you can BUY one for a lot less than trying to cobble it together..

You cannot just swap stuff around in a BMW like a Honda. BMW on the later cars has made it dam near impossible to "just swap it" like in the cars pre 1999....

I am doing an S54 swap into my E36 non sunroof track car...Guess what.. You literally have TWO options only... The Bimmerworld ECU/swap kit for $3300.00 or a stand alone programable ECU for about the same price...

Even better...

Contact Technique Tunning and buy a turbo kit.. Overall probably cheaper and will make more power...

And yes thats TWO thumbs down...

You need to listen if you ask for advice I suggest take it. Especially with what you are talking about. I have master BMW tech buddies who would not even attempt to do what you are JUST due to the amount of electronics involved...

In reality, if he wants to do it and spend his own money, he can.

The ECU issue that you are dealing with is not the same for him. It should be a simple harness/ECU swap and reflash of some modules. The 01' non-Ms came with DSC and electronic throttle as well, so it's all a matter of getting everything to work together, unlike the E36 platform.

I do agree that the swap is pretty stupid though. A real swap would involve a V8.

**wanganstyle** · 09-11-2011, 01:59 PM

I think the OP just hasn't had the time to read through the many successful threads WITH POSTED SPECIFICS of the s54->e36 chassis swap. I know they are out there and many members that are not so noob (post count more than 15) will have already read them.

z3 is a e36 chassis, s54 swap is just the same as any e36m+s54.

If he cared about financials, he would already know it is a $10k affair ++ espically if restoring a FLOODED s54!!!.................................WHY!!! when a good one can just be purchased to build from.

Rebuilding a prior water soaked s54 should not be done period. Sorry, S54 is not a lets throw it in a flood and it can survive kind of engine. Cheap s54 = scrap metal, don't touch it.

**hitthequandt** · 05-26-2016, 11:27 AM

Originally Posted by GGray

REALLY

Everyone has basically told you do not to waste your time. But feel free to completely ignore the wealth of expierince here and attempt something that is not only ridiculous but compleltely not needed since you can BUY one for a lot less than trying to cobble it together..

You cannot just swap stuff around in a BMW like a Honda. BMW on the later cars has made it dam near impossible to "just swap it" like in the cars pre 1999....

I am doing an S54 swap into my E36 non sunroof track car...Guess what.. You literally have TWO options only... The Bimmerworld ECU/swap kit for $3300.00 or a stand alone programable ECU for about the same price...

Even better...

Contact Technique Tunning and buy a turbo kit.. Overall probably cheaper and will make more power...

And yes thats TWO thumbs down...

You need to listen if you ask for advice I suggest take it. Especially with what you are talking about. I have master BMW tech buddies who would not even attempt to do what you are JUST due to the amount of electronics involved...

God damn harsh much? Let him spend the money if he wants to.

**LSxDreamer** · 05-26-2016, 06:00 PM

Dude that comment was nearly 5 years ago...

**TerraPhantm** · 05-27-2016, 01:23 AM