CARB Legal E30 N51B30 Swap

[Yo.goob]

Hello everyone,


New to the R3V community and with the nerve to tackle on something nearly impossible as far as swaps are concerned for the folks out here in CA. As some of you may know, we don't get anywhere near the same leeway for engine swaps as the rest of the U.S (with some exceptions) due to emissions equipment and OBDII functionality for our older E30's. A whole lot of technical advancement as well as first-hand knowledge has stemmed from the N52/54 forums, with the most noticeable progress being all the drivetrain and powertrain kinks being ironed out (GS6-17bg 6-speed fitting in OEM transmission mount, E36 m3 driveshaft, multiple combinations of differentials, pinion alignment, front sump oil pan, E85 z4 mounting arms, etc.), leaving the hardest part of the electrical and wiring to be sorted. In addition to this, I am trying my hardest to solve the puzzle of successfully fitting an N51b30 along with all of its emissions equipment and necessary parts to make it pass CA emissions and BAR! The donor vehicle is a 2009 BMW E90 328i with the SULEV N51b30 and MSV80.1 ECU, and the recipient E30 is a '91 318is.





Excuse the rats nest and mess!



You can call me a dreamer, naive, or just another idiot who has no idea what he's doing but remember that the standard N52 swaps were considered impossible as well up until recently once people realized that the potential to get it working was not just some fairytale.

Now on to the good stuff.


I am making an active effort to keep track of every bit of shared information in these forums to make this swap as streamlined as possible for future E30 owners or those who are in the process right now. The first of which is the State of California Engine Change Guidelines, so long as CA legislation does not change in the near future, I am attaching a copy of it here in this thread for reference in case there is any doubts or some oversight on what can and cannot be done in terms of modifications/fit & finish.


A quick summary of what the guidelines are:



- Stock motor with ALL certified OBDII functionality
- Any intake/exhaust mods can only be done in order to accommodate fit & finish to engine bay, cannot remove any emissions functionality
- If the recipient vehicle is OBDI, transmission and EVAP system configuration can be left alone but must function correctly
- Be able to pass tailpipe, OBDII readiness, MIL (Check engine light), visual inspection, Catalytic and O2 placement, and CALID + Calibration identification number (CVN)
- Aftermarket modifications must be DOT/BAR/EO approved


With all this in mind...


This will no doubt be one of the most technically challenging things I have ever attempted so far, but I have the time and energy to see this through until I finish engineering school. Criticisms are sure as hell welcome, but without the support from the rest of the R3V and Bimmerforums community, I don't think any of us would have as much fun wrenching on our beloved E30's :)

Last part of the post will be a handy wiring diagram for the E30 318is and a link to purchase a free chassis wiring diagram for an n5x swap from Garage-a-holic


There will be more updates and info to come as time goes on, this should be a very busy summer!

[projectJTv4]

Excited to see a fellow swapper in CA! You def passed some hurdles already having access to the donor car with the catalytic converters. They were such a pain for me to obtain.

[hoveringuy]

My biggest question is how the stock cats will cooperate with the CABS , swaybar and subframe. Everything else should be straightforward.

[Yo.goob]

So far that is also the biggest concern for the fitment of the engine, otherwise this would've been as simple as following you guys on the other threads :( There are a few specialty European auto shops that tackle these types of problems out here in the LA/OC areas that I have been meaning to get back into contact with to get a better understanding of what to do and how to jump this hurdle. Castro motorsport and Leichtbauch Werks have helped me with some problems in the past and for the more unique challenges, their advice is golden.


Much like the other people on this forum, if I find a configuration that works for the exhaust I'll link a CAD file for everyone to use for future reference with all the necessary good stuff.
Also in the process of learning how to make and use carbon fiber for one off pieces and since this swap is also a golden opportunity for a restoration of the chassis, it'll give me (or anyone else who is willing to lend a hand) a good chance to replicate certain parts that are either NLA or unreasonably expensive. Since swaps can be incredibly cost-prohibitive, I'd like to make it easier for all of us to get access to all the parts that we need :)

More updates to come this week

[slammin.e28]

Don't forget that pesky radiator mounted temp sensor or whatever it is. IIRC it basically just needs to be installed, doesn't actually do anything but tell the DME that the expensive ass air scrubbing radiator is installed. I sourced a rad that wasn't a scrubber but had the spot for the sensor, then carefully swapped the sensor from my broken rad. Worked just fine, no codes, no CEL. IIRC it was a CSF brand for a 2011 328i. Be careful tho, that sensor is very brittle and easily broken upon removal. IDK if you can code it out, but figured if you're trying to make EVERYTHING work on the emission side of things with the N51 I'd mention it.

Also pull the VC and check those VANOS bolts....

[Yo.goob]

Ahh yup, the Environmental Air Catalyst sensor (EAC) is a bit of a pain to re-integrate into the E30 chassis since, like you said, it's only purpose is to prove that it contains the manganese-oxide coating for some type of ozone protection on the radiator! I've seen a fair share of troubles from the guys on the N51 forums across the web talking about how to avoid paying that $600 OEM premium radiator part by coding it out or just re-using the old sensor onto a new radiator but knowing the state referees, they'll immediately flag something like this at their earliest convenience.

Had a brief discussion with one of the referees a week ago about technicalities and other things that may pose a problem down the line as far as modifications and stuff is concerned and the biggest thing that killed me (ironically enough) are the little details like this. They even heckled me about using the N54 intake manifold for extra clearance for the E90 brake booster + Mk60e5 ABS module, even though the DISA and N54 intake are functionally the SAME, including the emissions equipment. California legislation strikes yet again at car enthusiasts, but that won't stop me from finishing the swap.




Onto the next bit of progress











Finally managed to source a 6-speed manual GS6-17bg from our English friends for a decent price. Even came with the associated slave cylinder and bare essential goodies, now just waiting for the other hardware to mount it to the engine and wiring harnesses + pedal assembly for the proper DME communications and all that jazz.
















Finally stripping down the N51 to its bare bones and inspecting every single damn part that looks aged or otherwise in need of replacing since I would 100% want to avoid the headache of needing to replace anything once everything is tucked comfortably away into the engine bay. Valve cover seems to be in decent shape, with the exception of the VCG, Eccentric shaft sensor gasket, and the Valvetronic motor gasket leaving traces of leaks. Ordering replacement parts this week!

Last bit for actual placing of the engine into the E30 is ordering the oil pan from SendCutSend.com with the help of JTv4 and Hoveringuy and their .DXF files! The 24v AKG poly mounts as well as the Z4 mounting arms have been sitting on the shelf patiently for everything else to come together. Meanwhile, looking for a skilled welder willing to take on this oil pan job and from then on it's just figuring out how the hell to fit the emissions stuff without too much complex fabrication or plumbing!

[DesertBMW]

I don't see N52 as a good swap at all. It is not easy, it is not cheap, barely gives more power than M54b30 and the swap is way more complicated.

[Yo.goob]

People have swapped just about everything into the E30 chassis, cost-prohibitive or otherwise so I will respect your opinion that this isn't something you would do.
If you haven't already looked at the rest of this thread, there are a good amount of successful N52 swaps and seems like they are happy with their decisions to transplant that motor into their E30.

[roguetoaster]

Keep going OP, this certainly registers a bit on the WTF side of the swap spectrum, but that side of the scale also produces all manner of sly grin inducing weirdness.

I think it'll be very interesting to see how CA views some aspects of the swap, such as the allegedly forever sealed fuel system, and whatever other components are or are not considered necessary emissions components for this swap.

[Yo.goob]

100% without a doubt on the WTF side of things, but still doable albeit with a lot of creative thinking and knowing both the E90 & E30 chassis inside and out.

CA officials definitely don't like this swap since they see the complexity from miles away and are worried about the K+DCAN wiring integration along with the modules, but a good amount of that stuff isn't necessary since it isn't emissions related.
The N51 SULEV tank definitely sucks a bit since there is a whole lot tucked away and there aren't any schematics that describe what's going on. However, the engine change guidelines state that the EVAP equipment can remain in the recipient vehicle configuration (E30 EVAP) as long as the OBD system can monitor what's going on with the fueling system.





An absolute mess of EVAP and emissions equipment going on in there.

(Thank Stephen Cox on YouTube for getting us this wonderful video on the SULEV fuel tank! This is the only reference I could find on what the heck is going on in there.)

Really confusing to figure out the best way to reintegrate it all but we can get back to that in due time.

[hoveringuy]

I don't see N52 as a good swap at all. It is not easy, it is not cheap, barely gives more power than M54b30 and the swap is way more complicated.

I've had both M54 (two...) and now N52. I was pretty satisfied with the M54 but it took a lot of work to get 245whp (Schrick cams, headers, porting, M50 intake) and I was always waiting for the oil pump to fail from harmonics. It was definitely easier but I wouldn't wish the E34 pan on anyone, either.
Even with 245whp, it was pretty weak at the bottom without DISA and I had to run Megasquirt to make that all work.

The N52 is definitely a more difficult swap, but the VANOS is far superior, it doesn't leak nearly as much, is generally more refined and with nothing more than headers makes 245 on a completely stock motor. I presently have the dual-DISA intake which has lots of low-end torque but starts to run out of steam by 6800, whereas the n54 intake was still pulling through 7500. The M54 intake ports looked like rough-cast crud and the exhaust ports were horrible. N52 is fully CNC machined and just looks like a jewel. Plus bedplate crank, light-weight and the magnesium block is SO smooth! (magnesium is fantastic at damping)

We can all agree that finding a decent M50/M52/S50/S52 is pretty tough these days and even M54's are going on 20 years old. N52's are still new enough that they're falling out of the dismantling yards with decent mileage for pretty cheap.

CARB legal is challenging, for sure.

[DesertBMW]

I've had both M54 (two...) and now N52. I was pretty satisfied with the M54 but it took a lot of work to get 245whp (Schrick cams, headers, porting, M50 intake) and I was always waiting for the oil pump to fail from harmonics. It was definitely easier but I wouldn't wish the E34 pan on anyone, either.
Even with 245whp, it was pretty weak at the bottom without DISA and I had to run Megasquirt to make that all work.

The N52 is definitely a more difficult swap, but the VANOS is far superior, it doesn't leak nearly as much, is generally more refined and with nothing more than headers makes 245 on a completely stock motor. I presently have the dual-DISA intake which has lots of low-end torque but starts to run out of steam by 6800, whereas the n54 intake was still pulling through 7500. The M54 intake ports looked like rough-cast crud and the exhaust ports were horrible. N52 is fully CNC machined and just looks like a jewel. Plus bedplate crank, light-weight and the magnesium block is SO smooth! (magnesium is fantastic at damping)

We can all agree that finding a decent M50/M52/S50/S52 is pretty tough these days and even M54's are going on 20 years old. N52's are still new enough that they're falling out of the dismantling yards with decent mileage for pretty cheap.

Good M54B30 is dirt cheap now. Idea is to buy the whole car, E46 are out there selling for $800 on Facebook marketplace all good and running with other issues that make the car very cheap. I bought 2004 330ci manual for $800 and I drove it home, reason why it I got it for cheap is because convertible top got torn and interior was a mess, no one wanted it. So I got the M54B30 with ZF transmission and all the parts that I would need then I sell rest of the car in scrap for $400 and I have a good running M54 with good known transmission. You just can't beat that. And M54 as long as it is not overheated it is good. Then swap is easy, everything just bolts on. I am running my E30 with E34 oil pan for 14 years now and no issues, My E30 is on stock springs.
Then I know N52 is a great engine and you can buy 2007-2009 E90 for cheap also, but the amount of fab work that you have to do for a swap and then compare that with benefit...

[Caperix]

Other than having to make an oil pan, the swap is the same amount of effort. Nothing wrong with either engine but the aluminum m5x engines have some known issues, oil pump & head threads. The n52 is not perfect either, non keyed crank hub, cam bearing ledges, but every engine is a 3.0 & the newest ones are only 12 years old compared to 16. The swap also opens up factory turbo engines as the n54/5 share designs so it's great for the future of e30 modding

[hoveringuy]

Other than having to make an oil pan, the swap is the same amount of effort. Nothing wrong with either engine but the aluminum m5x engines have some known issues, oil pump & head threads. The n52 is not perfect either, non keyed crank hub, cam bearing ledges, but every engine is a 3.0 & the newest ones are only 12 years old compared to 16. The swap also opens up factory turbo engines as the n54/5 share designs so it's great for the future of e30 modding

I remember when M50 swaps first became a "thing" and how difficult they were! The angled G260, the heater core connection, the C101, inflated OBC, CAB exhaust interference, etc.

The N52 will get easier with each one. I think most of the figurin' out is done.

and that reminds me... I will commit the little alternator light trigger that I've had working nicely in prototype form to a board soon. (N52 has a CAN controlled alternator so it doesn' have the second set of field windings to trigger our "ALT" light...)

[DesertBMW]

The N52 will get easier with each one. I think most of the figurin' out is done.
...)

So after all this time one still has to use MSV70? Hasn't the MSV80 been figured out to be used without CAS?