First start 1975 BMW 2002 m20 swap

[whatyear]

Hey everyone,

 

I'm an infrequent poster but longtime forum member and attendee of the Brisbane meetup. During the pandemic, my m20 swap project has really picked up and I just fired it up for the first time last weekend! A friend and I have done all the work (if it isn't obvious ?). I've taken photos and videos along the way but haven't posted much outside of http:instagram.com/whatyearisthat

 

This car is a rust survivor and we've replaced the entire floor and repaired quite a bit of the body (still need to do the spare wheel well but that can wait). The on-going plan is to store the OG vin-matching engine but swap in an m20 and overhaul basically all systems (goodbye money ?). It'll be a performance oriented sleeper (no fender flares, airbags, body kit-- but you do you) for driving around CA.

 

Anyways, I got the engine test fired (it's the 2nd m20 as the first had no compression) and I'll hook up the custom driveshaft and suspension this weekend. Then brakes, more wiring, exhaust, tires, dial in suspension a bit, test drive, etc

 

 

The car:

- 1975 BMW 2002 saved from the hells of rust, purchased from a man liar in Oregon before I knew better

 

The engine:

- 1990 m20b25 stock

- Basic maintenance- gaskets, seals, timing belt, plugs, wires, coil, etc

- Oil cooler, AC, power steering, fan, heating delete

- throttle body with coolant delete and SSSquid spacer

- received racing pros chip but going to run stock ecu for a while

- IE m20 swap headers

- 1990 honda 3 row aluminum radiator w/ Mishimoto fan + relay kit

 

Suspension/drivetrain:

- Ground Control coilovers

- Reinforced front subframe from IE

- IE roll center spacers

- Catuned Monster adjustable rear subframe with 3.93 e30 diff

- Getrag 260/5 w/ custom mounts

- ACG tunnel-mounted shifter

- Shortened and balanced e30 driveshaft

 

Brakes:

- IE big brake kit front and rear

- Chase bays brake booster delete & e30 rear brake line set, handmade front line

 

Wheels:

Rota 15x7 mesh

 

MGI Speedware 12 circuit fuse box-- slowly building my own harness but using the stock m20 engine harness

 

**Not sure about exhaust or wheels yet-- any advice??

If you're still reading, thanks for checking out my build!

 

Edited February 17, 2022 by whatyear

[Mike G]

How was the install and fit of the IE headers? I watched a lot of YouTube videos on various m20 exhausts and my favorite had vibrant resonator and muffler. 

[whatyear]

The IE headers have been great so far. Very high quality and no issues aligning with the studs. A small racheting wrench made it go much faster since there isn't a ton of clearance to get a socket wrench in there. I picked up their stud and copper nut set to replace the old hardware.

 

Just looking into Vibrant now-- sounds amazing with a nice rumble as the engine decelerates.

 

The headers have a 2.25 out and I'll need a custom downpipe/collector from there w/ an O2 bung but not sure on sizing from that point back.

[Bibm5]

Nice work. Let's see some pics of the car now 

[Mike G]

2.25 is plenty for a stock m20. For strokers 2.5 is popular, 3” for turbos but that might be overkill. 

[whatyear]

10 minutes ago, Bibm5 said:

Nice work. Let's see some pics of the car now 

 

Here are a few: definitely a 20 foot paint job that I'll eventually remedy

and pardon the cinder blocks  -- I work in a friend's lot and the ground is less than even so we went overkill vs trusting floor jacks

 

[2002iii]

Sounds nice! I wouldn't run the engine for too long without an air filter and exhaust.

 

That radiator looks a little small for an m20 and I would suggest you run the factory m20 oil cooler.

 

Lots of options for exhaust, I like the Ansa muffler I have on my 02. I have a Borla catback on another vehicle that's nice too. I used to know a guy that had a Flowmaster muffler on his e36 325i, I was surprised by how good it sounded.

 

Lots of shiny new suspension parts!!

 

I would suggest getting a set of e30 basket weaves instead of the Rotas.

[Mike G]

6 minutes ago, 2002iii said:

Sounds nice! I wouldn't run the engine for too long without an air filter and exhaust.

 

That radiator looks a little small for an m20 and I would suggest you run the factory m20 oil cooler.

 

Lots of options for exhaust, I like the Ansa muffler I have on my 02. I have a Borla catback on another vehicle that's nice too. I used to know a guy that had a Flowmaster muffler on his e36 325i, I was surprised by how good it sounded.

 

Lots of shiny new suspension parts!!

 

I would suggest getting a set of e30 basket weaves instead of the Rotas.

Radiator looks like the triple core civic radiator that others have used on M20s with no issue. 

[whatyear]

1 hour ago, 2002iii said:

Sounds nice! I wouldn't run the engine for too long without an air filter and exhaust.

 

I appreciate the advice! Good call on the air filter-- I put a K&N filter on after that test run after making a simple bracket. I'll plug off the exhaust to keep moisture/debris out until installing a full setup. I'm optimistic on the radiator setup w/ the 14 inch mishimoto fan & adjustable temp sensor and I'll wire in a switch in case it's running hot. I opted to slice a section out of the nose to slot in the radiator so hopefully it works out ?

 

Some good options there on exhaust. I'll do some more homework on those options. Any shops in the Bay Area you'd recommend for install? I'm still on the fence on DIY or paying a shop so I can get to driving.

 

Rotas also fall into the get-me-driving-and-consider-replacing-later category. You really can't go wrong with the e30 basketweaves or maybe some Panasports. If i avoid the US-880, the Rotas should hold up  

 

 

air intake on the 1st (no compression m20)

Edited February 17, 2022 by whatyear

[Overdraft]

3 hours ago, whatyear said:

 

 

I appreciate the advice! Good call on the air filter-- I put a K&N filter on after that test run after making a simple bracket. I'll plug off the exhaust to keep moisture/debris out until installing a full setup. I'm optimistic on the radiator setup w/ the 14 inch mishimoto fan & adjustable temp sensor and I'll wire in a switch in case it's running hot. I opted to slice a section out of the nose to slot in the radiator so hopefully it works out ?

 

Some good options there on exhaust. I'll do some more homework on those options. Any shops in the Bay Area you'd recommend for install? I'm still on the fence on DIY or paying a shop so I can get to driving.

 

Rotas also fall into the get-me-driving-and-consider-replacing-later category. You really can't go wrong with the e30 basketweaves or maybe some Panasports. If i avoid the US-880, the Rotas should hold up  

 

 

air intake on the 1st (no compression m20)

In shopping for exhaust, check out Supersprint out of Italy.  It really sounds just right….0 drone ….and beautifully made - price didn’t offend me…fit perfectly.

[Mike Self]

Be VERY careful with those cinder blocks.  While solid ones may be OK, hollow ones can crack/break without warning; bad enough for the car, fatal for you if you're underneath.  Please please please either use solid concrete blocks or, even better, jack stands to support your car, especially while you're under it! 

 

Many years ago, at the dawn of 2002s in the US, I lost a friend when the 02 he was working on, supported only by a jack, fell on him and killed him.  

 

mike

[whatyear]

10 hours ago, Mike Self said:

Be VERY careful with those cinder blocks. 

I appreciate your message, Mike and I'm really sorry for your loss. I do have some jack stands and motorcycle-type lifts. I'll create some addtl. safety points on each corner before going under it this weekend!

 

I grew up outside of Cleveland and went to school in Akron. Hope all is well in OH!

[whatyear]

Quick update on my build!

 

In the last few months, I've done the following:

- Wired up basic systems using the MGI speedware 12 circuit panel. Includes classicautoled tail light LED kit, dual hella horns, h4 headlights,  manual switch for mishimoto radiator fan. I've found learning wiring/electrical to be one my favorite parts of this build

- Installed new IE e-brake lines

- All fluids-- brake & clutch, transmission, diff and steering

- Made some replica euro turn signals w/ bright LEDs. These work as running + turn signals. They need some touching up but I'm happy to not spend $400 on new ones and run these for a while

- Rota (i know) 15x7 wheels installed w/ 195 Yokohama Advan Flevas and car back rolling

- Tested reverse and 1st gear-- what a relief to know the car at least rolls and the transmission isn't s***. phew

- Added more dynamat to the interior, cleaned up seats and installed

- Cleaned up front grill

 

 

What's up next:

- Install IE pedal + 24 inch universal lokar cable

- Start on gauges-- Speedhut GPS is coming and I got a deal on a tach converter. I'd like to do new bulbs. Overall the wiring diagram for this is tricky

- Weight and torque suspension. Get another set of Ground control spring pads for lower rear

- Start to plan the exhaust-- lots of good suggestions in this thread. I attached a photo of Kooglewerks setup that I'm thinking of using for inspiration. They're developing some nice options but I don't think any m20 support would come in time and while their quality justifies their prices, i'd need to sell a kidney.

- current plan (2.25 inch the whole way back) : my IE m20 swap headers (ends in 2 2.25 vbands) > 2 to 1 collector w/ O2 bung > mid-section resonator > rear muffler out the center

 

Any recommendations on Bay Area muffler shops or exhaust setup advice (m20 swap) much appreciated!

 

 

 

 

 

exhaust inspiration

[AustrianVespaGuy]

Agh, all that hard work but all I can see is that miserable AFM on the fender! Let me know when I can talk you into spending more of your money to ditch that thing and go Megaquirt!  If you're using the donor M20 engine harness, there are Plug-n-play solutions available. . .

Great looking headers on the other side of the engine bay though!

[AceAndrew]

Awesome, happy to see another m20 swap!  Do you have a build thread on here?  
 

Glad to see someone put the headers to hood use.  They are the result of a long long back story. FIY the same fabricator that made the headers is the same that made that exhaust!

 

Ive been working with vibrant and that fabricator on a titanium m20’02 exhaust.  Should also be possible in SS.  Unfortunately, the timing probably won’t work, given you’re further along in the reassembly process.

 

Mind sharing wiring details?  I’m starting that journey right now and looking for examples.