CARB Legal E30 N51B30 Swap

[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!

[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]

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

[hoveringuy]

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

[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.

[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!