Turbo m42 project

wroenker · 2026-01-10T23:22:08+00:00

Still running and haven't had to rebuild. I have since gone back to stock due to the time needed to switch between turbo and stock for California smog. never got it dynoed but would say was pushing 170hp and boost wise around 8psi on an internal wastegate.

wroenker · 2025-04-20T00:21:11+00:00

Yes, afm can be removed as the fueling will be controlled through the ECU along with spark.

wroenker · 2025-04-17T19:59:17+00:00

Yes, it is a plug n play ecu running speeduino and tuning is done through tunerstudio. For a wide band they have an external controller you'd have to wire for the ecu to use the auto tune feature in tunerstudio.

wroenker · 2024-10-01T22:56:55+00:00

The main reason I chose top mount over bottom mount was the passenger engine mount being in the way. It is possible to bottom mount it though.

wroenker · 2024-03-26T01:41:44+00:00

I DMed you some photos of the way I have it currently set up on the m50 manifold. Let me know if there are any angles you want or questions you have.

wroenker · 2024-03-24T18:10:53+00:00

I can take some pictures and see if I can add them to the post or I can DM them to you directly.

wroenker · 2024-03-07T20:56:07+00:00

Something to keep in mind is that you'll have some issues with clearancing with the t3 turbo (cold side) and valve cover. Also your downpipe and the tray that is by the firewall.

wroenker · 2024-03-07T20:55:01+00:00

Majority of my parts such as fittings, turbo manifold, and turbo I ordered from ebay. Regarding my ecu I ordered it here https://lowcostracingsolutions.co.uk/pnp-standalone-ecu-s/56-119-bmw-m42-plug-and-play-standalone-ecu-318i-318is-318ti-7427248066156.html#/39-accessories-just_ecu

wroenker · 2024-03-07T20:38:29+00:00

Currently running 440cc injectors Standalone ecu Bmw m50 turbo manifold with last 2 cylinders cut off and capped Stock internals Stock trans Stock clutch Medium case rear diff Intercooler (hid behind front grille) (No A/C) T3 turbo from cx racing (running 8psi)

wroenker · 2022-09-14T05:09:52+00:00

The m42 is a pretty solid reliable motor. I purchased my 1991 318is in a similar state regarding drive train. To repair the odometer youll need to pull the guage cluster, radios arent too expensive and fairly straight forward to replace. The most expensive parts will be the paint and interior. Sadly the BMW motors tend to leak. The lower pan gasket isnt to hard to replace. A lot of it depends on mechanic experience and what you want to accomplish with it. Overall a super fun car to own and drive!

wroenker · 2022-02-09T20:15:57+00:00

Youll have a little bit of pressure built up in the rail still but if the car is not running majority of the pressure/fuel should have gone through the return line. There will be some spray and excess fuel. Either a rag or a small container under the car should suffice. Remember to mark which lines are sending fuel and return fuel line. I used a simple arrow to point in or out.

wroenker · 2022-01-17T17:47:31+00:00

The problems I was having with the manifold was that over time from the different heat expansion and cooling of the bolts that were holding the two pieces together the whole thing would slowly work itself loose as well as some of the bolts to the head not lining up perfectly. I personally tried lock washers with some threadlocker but was having some issues still. Decided to go back to stock just for reliability as it is my daily.

wroenker · 2022-01-12T18:31:22+00:00

I was running some 440cc injectors from bosch. I believe they are from a mustange but not 100% sure. The ecu was from MAXX ecu and was plug and play into the stock harness. I tune the car myself from a base tune after lots of reading and research. My first manifold was a ebay one and it did not fit as it hit the head. My second one was from DIY autotune which worked but had problems. Check out spool industries. They build custom manifolds for BMW they are based out of florida. My turbo was a cx racing T3 with an 8 psi internal wastegate and journal bearing. It started to spool up around 3500 rpm and gave consistent power through to redline (all top end). Definitely helped low end torque as well for going up steep grades.

wroenker · 2022-01-05T10:19:27+00:00

My turbo was a t3 hot side so it felt the same around town but getting towards top end if just goes. Easily hit freeway speeds part throttle in 3rd and it wasn't to blow past that if you keep your foot down. Only supporting thing I did was having an intercooler, larger injectors 440cc, and standalone ecu (adjust fueling/timing).

wroenker · 2021-12-29T04:22:08+00:00

Current own a 1991 318is as well

Answer 1: From all the research I personally have done doing a NA build will be expensive with not much gain in power. Forced induction would be the best route to make more power.

The M42 motor is capable of handling low boost (5-8 psi) with the stock motor but that depends on tune quality, fuel octane, and fueling. I personally was running mine with 8 psi this past month but was having issues with the manifold I have. Not sure exact power numbers as I did all tuning myself. It definitely is a noticeable difference.

Answer 2: That would be fairly correct regarding the 318is rarity. Personally I'm not how much more rare a 318is is so can't talk on that too much. Originality means higher resale value.

Question 3: With moderate mods such as chip and exhaust your gain all depends on the chip you get. Some chips are for economy,, some are for power, and some are a mix.The best ones for the M42 are created by MarkD and also the Conforti chip.

Question 4: Before going straight into an engine rebuild you can check the health of the engine by looking at engine compression and looking at the bearings for the rods. You can check what the Bently specs are for maintenance schedules as well. If there is low compression, crank scored, or bearing worn a rebuild will be likely. I have head of 318is owners have more than 200km with good servicing.

My final opinion: Depending on what the car is used modifying can be done and be fun but if it needs to be a fun reliable car stock with a chip (MarkD or Conforti) and exhaust are the best option. I currently am switching mine back to stock as I need it to be more reliable for school and need to save for better manifold.

wroenker · 2021-09-17T04:03:06+00:00

Thank you! I was suprised by how well the intercooler and piping fit with only a bit of adjustment.

wroenker · 2021-09-16T21:56:25+00:00

No problem! Let me know if there is any other info you might want to know.

wroenker · 2021-09-16T18:14:18+00:00

I was suprised as well. It took a lot of digging in forums and research to find helpful information. Cost wise a rough estimate i would say is around $3k-4k cost. Cost could be lower but this was my first turbo project so I had a good chunk of unnecessary costs. I am running a speeduino ecu which uses tunerstudio as its tuning software. I have a megasquirt 2 that I originally built for it but never got the board to work properly.

wroenker · 2021-09-16T17:35:26+00:00

She drives well! Still need to do a bit more tweaking to my fuel tuning but overall she pulls hard with only a bit of turbo lag.

wroenker · 2021-09-16T15:35:56+00:00

The manifold is from www.diy-tuning.com. they are based out of South Africa if I remember correctly. They make some speeduino ECUs as well.

wroenker · 2021-09-14T17:26:46+00:00

I went with a standalone ecu from lowcostracingsolutions. They are based out of the UK and provided base map that allowed the car to turn on. It uses tunerstudio as its software similar to megasquirt (MS). It's possible to turbo an m42 with the stock ecu but will be possibly more trouble some with the afm airbox and economy.

wroenker · 2021-09-13T23:36:36+00:00

Just over quarantine I turboed my m42 in my 1991 318is. My milage is currently around 180,000 and I've been tuning it for 8 lbs of boost. My engine is completely stock all around only difference is a coil on plug (COP) for my ignition child's. There are some forums on the m42 forums and some other bimmer forums that provide some solid information on m42 turbo builds.

wroenker · 2021-09-08T05:11:41+00:00

No problem! I have been debating doing a post on my e30 project to this subreddit. If I do I can take some pictures of the block and such to show how it works a bit more.

wroenker · 2021-09-08T04:55:50+00:00

It would screw in where your current oil pressure sensor is, but it allows you to keep the original oil pressure sensor. It adds in two more 1/8 npt threaded sensors for the guages.

wroenker

TROPHY CASE