1994 BMW 318is M52 Swap & Turbo Build

[R.Thomas]

Hi all, my name is Rob. I had a prior BF.C account that apparently got locked due to inactivity (thus the low post count on this username, which was assigned by BF.C...). In any event, after 15 years of ownership, I have decided to finally do an engine swap and build on my 1994 Mauritius Blue 318is (see photo below). This was my first car, purchased when I was 16 in circa 2004. I also had a 1995 Dakar M3 for many years and several other non-BMW vehicles, including a lifted 1988 Jeep Cherokee XJ 2-door with a 5 speed manual and my current daily, a lifted 2007 Subaru Forester with a 5 speed.

My goal with this build is 450whp on E85 with stock internals. I have a somewhat flexible budget and may do a fully built motor with forged pistons / aftermarket rods for peace of mind and the ability to run higher power in the future, if desired. The car currently has AST coilovers, Momo Monte Carlo steering wheel, along with a few other "cosmetic" modifications that I plan to reuse. It is my 2nd/3rd vehicle and, historically, I only put about 1,000 miles (or less) on it per year.

With that introduction out of the way, here is a summary of my parts list (major components only). I have done months of research and planning on this build and am starting to purchase the parts. I look forward to feedback from the FI experts here (a la Butters, Someguy, E36Hater, et al.)

Engine/Turbo
US spec M52b28
All new gaskets, seals, etc.
S50 cams
ARP 2000 head studs
CES or equivalent cut ring head gasket (stock compression)
RSI Turbo Manifold (purchased - ​photo below)
Borg Warner S257sxe turbo
Turbosmart or Tial 44mm wastegate
Turbosmart or Tial 50mm BOV

Drivetrain
E36 ZF320 transmission
Southbend stage 3 or equivalent clutch
Stock dual mass flywheel
E36 3.15 LSD
328/M3 drive shafts, axles, etc.
DSSR and upgraded shifter bushings

Fuel/Tuning
RK Tunes E85 tuning package
Walbro 485 fuel pump
Stock FPR and lines

Cooling
Mishimoto or CSF aluminum radiator
Spal electric fan
Treadstone TR1235 intercooler

Gauges
Innovate or equivalent: boost, AFR, and E85 content

Chassis
Front and rear subframe reinforcement
Upgraded bushings, mounts, etc.

[someguy2800]

Your also going to want to get an M50 intake manifold and the associated parts to put it on the M52, and will need some sort of crankcase vent catch can. You may or may not need to upgrade the fuel pressure regulator with the 485 pump.

[R.Thomas]

1. Is the manifold swap recommended to avoid OBII or for the performance gains?

2. Yes, I plan on getting a catch can.

3. Noted about the fuel pressure regulator. I added it to my spreadsheet as a "possible / miscellaneous" item.

Appreciate the quick input.

[PowerKraut]

Car looks awesome. Would love to see the M42 on boost tho


1. Stay with the 1.8
2. All the boosts + E85 --> 400+ hp
3. Profit
4. If it blows, swap to the M50 you've built meanwhile.

<3

[R.Thomas]

PowerKraut, I had considered sticking with the 1.8 liter M42 but after doing a lot of research, I determined it wasn't worth it for my power and reliability goals, along with the lack of aftermarket support.

Don't make me second guess myself any further!

[IR M5]

The M50 manifold will yield significant power gains when paired with a turbo. Also, the stock obd2 manifold was never intended to see boost so it will leak under boost. Definitely not worth keeping. I would also recommend getting the Maxpsi IACV hose setup and TB coupler.

Boosting the M42 would be a lot of work and you likely won’t get the results you’re looking for. You’ll also have to redo several parts of the system if you choose to swap in an M52 later on. Building a turbo car twice is a lot of work!

[PowerKraut]

Boosting the M42 would be a lot of work and you likely won’t get the results you’re looking for.

I dont see how it would be harder than boosting the m50. you even got more space in the bay.

M42 + Arps + GT30 + E85 I see a lot of potential in the M42

[R.Thomas]

M42 definitely has potential. It just isn't the goal for this build.

And yes, I have the TB and ICV hoses on my list.

Sent from my SM-G920V using Tapatalk

[R.Thomas]

Is there a preferred exhaust manifold gasket? What about the turbo-to-manifold gasket?

[IR M5]

Is there a preferred exhaust manifold gasket? What about the turbo-to-manifold gasket?

The OEM gaskets work well for the head to manifold. For the turbo to manifold, I would just pick up some of the metal t3 gaskets off of eBay. Some people don’t even run a gasket between those two pieces, but that’s up to you.

[R.Thomas]

OK cool. Thanks for the info.

[R.Thomas]

I see a bunch of guys running the FX Stage 3 or Stage 4 clutches with the stock dual mass flywheel. The price of the FX kit is attractive but also a concern to me. I'd rather spend more money and not have to worry about the clutch failing prematurely because it's a cheap POS... So are the FX clutches actually decent or is the performance, reliability, and customer service of a company like Southbend worth it?

[R.Thomas]

Received the turbo. It's beautiful (see below). I also got the wastegate and BOV. Went with Turbosmart units. Plan on ordering the intercooler today (Treadstone 1235).

[R.Thomas]

Bump to re-request info concerning clutches. Are the FX clutches actually decent or is the performance, reliability, and customer service of a company like Southbend worth it?

[pbonsalb]

The anecdotal info (user reports here) have been good over the years for moderate power cars. Some say the hardware should be replaced with OEM grade parts (pilot and TO bearings).

I ran the highest level SB single from 2010 until this year at power up to about 675 rwhp and 600 lbs rwtq and liked it. I ran both the feramic and ceramic, changing only because the feramic fused to the flywheel at the dragstrip due to heat. I ran it with a replacement Luk dual mass flywheel since I had sold my original when I used an aluminum single mass and AA heavy duty Sachs clutch while supercharged.

For much over 500 lbs rwtq (or about 600 lbs at the flywheel), an 8.5” twin is probably the way to go. I think way back when I bought, my SB was rated at 720 flywheel or maybe 600 rwtq and was the highest full face single available. Full face improves street ability; a puck will extend capacity but not be as easily engaged.

DKM and others are making twin disks with flywheel that are much cheaper than the twins from years ago like UUC and CM.

[R.Thomas]

Were you using the stock DM flywheel with the SB clutch?

Thanks for the info, I appreciate it.

[R.Thomas]

So a bunch of updates: I ended up buying a 325i that had a complete S52 / ZF / M3 rear subframe (3.15 lsd) swap as a donor car. Moved my E36 to my dad's garage and I started taking apart the donor. I'll have the engine and transmission out by next weekend and then start stripping the rest of the car down to part out what is salvageable. Unfortunately the underside of the body (floors and trunk pan) have bad rust.

Donor car:


318is tucked into in my dad's garage:


Engine removal from donor:

[Mklock]

If you have not purchased a clutch yet, my Fx 6puck ceramic disc has held 620whp and 570wtrq. It's rated at only 400hp though so who knows. I got the Fx single mass flywheel too. Also, It has 35k miles on it and feels exactly the same as when it was new. Initially it's very chattery but breaks in good after 1500 miles or so.

Good luck!

[R.Thomas]

I have not purchased a clutch yet. I am considering the DKM twin disc but like most projects, there is a lot of "creep" with this one and I'm trying to stick to some sort of reasonable budget.

Thanks for the info!

[R.Thomas]

Also, I got the intake manifold off last night. Going to disconnect the exhaust and driveshaft tonight and keep plugging away.



In addition, I've been using the Quick Jack low profile lift while working in my garage. What a great piece of equipment. Highly recommended.

[R.Thomas]

Got the engine out this weekend. I was working all by myself which was a little bit of a pain. I also decided that I will be doing a full rebuild with forged pistons and rods, new chains, etc. What is the consensus about main and rod bearings? Is the OEM stuff OK or should it be upgraded too? Any other inherent weaknesses that I should consider as part of the rebuild?

[et89]

Nice, the way your 318is looks in your dads garage was the last bit of motivation I needed to remove my overfenders and restore the original fenders. Looks great! thanks!

[R.Thomas]

Thanks, I try to keep everything clean and OEM+.

[R.Thomas]

I made a lot of progress over the past few weeks. Have the engine stripped down to the long block. Also started on removing the rear subframe from the donor car.

In addition, I have a bunch of parts from the donor I am looking to sell, including a UUC Evo 3 ssk, sedan door panels (very good condition), along with a set of GC & a set of Bilstein coilovers. Check out the classifieds for more info and if anyone may need something specific, let me know.

[R.Thomas]

So I've been quietly plodding along with the build. I removed the whole rear subframe from the donor car and everything else worthwhile. I also have just about all my build parts purchased, including Eagle rods and JE/Athena cut ring head gasket. Also purchased a Turbosmart E-boost street controller, Garagistic chassis-mounted shifter, poly bushings (80A), and AEM gauges (wideband/boost combi, oil pressure, and water temp.). Still need to get a 6 cylinder instrument cluster (preferably M3) and a ZF driveshaft. This weekend I am bringing the 318is back to my garage from my dad's and will keep moving along.

Here are some pics if anyone actually still uses BFC