Im starting my M30 Swap.

[LagunaSecaBlue]

So I am selling my M20 out of my 89 325i.

PnP Parts list...

M30B35 engine
Getrag 260/5(Hopefully 6)
E28 535i Radiator
M30 ECU Chip

What am I missing, my local PnP is having a 50% off day coming up soon.

[uturn]

A 3.46 LSD, 4.10 will make 1st gear useless and 2.93 will leave you wanting.

[G-Man the Visionary]

decide what you're gonna do with the cooling system... I think ppl have a hard time with the firewall mounted overflow res... may want to get an extra hose to cut up and modify to fit the stock e30 res...

[navytapaul]

2.93 is great for the highway, pretty docile around town though.

Sent from my SAMSUNG-SGH-I727 using Tapatalk

[LagunaSecaBlue]

I have a 3.73 LSD. Also can I keep the A/C? I hear the I will run into overheating issues so is this swap dead in the water for me? It gets REALLY hot here in the summer. In stop and go traffic I could easily hit 115 degrees ambient temperature outside in the dead of summer.

[lukeADE335i]

I run my M30 swap without AC, and I have no overheating issues. I drove in 110 degrees two days ago (or 43 degrees... we're metric down here!!), and have sat in traffic in the past in 115 - 118 without issues. I run a 16 inch e32 pusher fan + Behr e28 535i radiator.

I don't see why you'd have too many issues with AC fitted + an appropriate fan.

I also run a 3.73 diff - lots on fun in city driving :) & fine on the highway, although I'm probably sacrificing some fuel economy.

As G-Man suggested - you'll want to reuse your overflow reservoir, and chop up some e34 & e30 hoses to make it work.

Easiest way to get together a comprehensive list is to have a read of Frank's guide (stickied at the top of the M30 & other swaps forum). I didn't do this when I did my swap, but it would have saved a lot of time / research.

[LagunaSecaBlue]

I am trading my M20 with another member on the forums who is local for his M30.

Couple of questions or matter of opinions...

1. Which Driveshaft and Transmission(I currently have a 325i Late Model Manual Driveshaft Rebuilt by Portland Driveshaft)

2. Use the M20 Loom or M30 Loom?

3. I want a late model M30, correct? C101 is a direct fit?(Besides a couple rewires for Blower/Windows) Oil Pan fits.

4. Replace entire ECU or just the Chip?

5. Which motor mount position? I am running A/C. Want best Weight Distribution(Does Position 3 work?)

6. Cooling options? I want this car as cool as possible. Just get a Electric Puller or also replace the Aux Fan with a better one?

Thank you.

[Bimmer_man]

Im doing this swap as well and here is what i am doing

1. Which Driveshaft and Transmission(I currently have a 325i Late Model Manual Driveshaft Rebuilt by Portland Driveshaft)

Custom single piece drive shaft

2. Use the M20 Loom or M30 Loom?

Usng a late model M20B25 harness

3. I want a late model M30, correct? C101 is a direct fit?(Besides a couple rewires for Blower/Windows) Oil Pan fits.

the best M30 according to paul burk ( M30 GOD ) a 86 M30B34

4. Replace entire ECU or just the Chip?

Im getting Megasquirt but a stock ECU for the M30 is fine

5. Which motor mount position? I am running A/C. Want best Weight Distribution(Does Position 3 work?)

im keeping my AC and powersteering and im using position 3 you will need to modify the fire wall

6. Cooling options? I want this car as cool as possible. Just get a Electric Puller or also replace the Aux Fan with a better one?

Im not sure what im doing with this one yet

Again this is what im doing you can do something else but thats what ive come up with

[navytapaul]

1. depends on transmission, if you have a g260, you can use the front half of and e28 and back half of an e30. If you go with a g265, you're going to have to shorten it about 2"

2. m20 is cleaner and doesn't have to be repinned, just get the plastics from the m30 harness and swap everything over.

3. Yes, but as I said above, the m20 harness works and doesn't have to be repinned. e32/e34 pans will fit and have correct pick up.

4. Entire ecu needs to be replaced. Even though they are both 1.3, the 179 ecu is different. Get a 179 ecu + chip and it will keep you happy for a while.

5. position 2 works the best, and requires the least massaging of the firewall. Position 3 is really far back and isn't needed for a/c.

6. Electric pusher works for me down here in Texas. Puller won't work in pos. 2 so yes, just replace the aux fan with moar cfm's.

[kronus]

the m20 and m30 getrag 260s are both the same length, but m30 one has the big giubo that also came on the 87 eta. you can swap transmission flanges from big to small and vice versa to accommodate a stock e30 manual driveshaft.

get a b35, it's better and already is set up for the sensors you need for a late model e30 harness. they mostly came with front-sump oil pumps, but some did come in 88-89 e24s which had mid-sump pans. you want the front-sump one.

[navytapaul]

m20 and m30 g260's have different bellhousings as well so they aren't interchangeable

[CorvallisBMW]

You can run A/C but you'll need the biggest (highest CFM) pusher you can find plus a small puller on the backside of the radiator near the alternator (10" wil fit). Make sure you wire it up to a low temp switch AND a manual override switch just in case.

http://www.r3vlimited.com/board/showthread.php?t=169097&highlight=Air+conditioning

http://www.r3vlimited.com/board/showthread.php?t=179952&highlight=cooling

Also don't forget you'll need e34 535i downpipes to clear the subframe and control arm bushings,

[LagunaSecaBlue]

Let me run this setup by you guys.

Late model E34/32 M30B35
Position 3 Mounts
Late model M20B25 Harness
Late model E34/32 Getrag 260
My E30 Rebuilt Manual Driveshaft(If I can)
E28 Radiator
Electric Fan
Upgraded Spal Pusher Aux Fan with the 80/88c switch
75 Degree Thermostat
Pull the ECU out of a E32/34

I want to run Position 3 mounts. I am planning on running the E34/32 Getrag 260 with a E30 Getrag 260 Output flange, can I still us my manual E30 Driveshaft? Who should I get my mounts from?

Any tips on a budget build?

[kronus]

you will need a small trans output flange and a lock ring to run that driveshaft.

you will also not be able to fit a mechanical fan, don't bother. It sits too high on the engine and hits the hood, even if you have room to the rad to fit it.

position 3 will be difficult. you will need more work to get the downpipes around the firewall, and general rear-of-engine maintenance will be inconvenient.

everything else is spot on

[LagunaSecaBlue]

you will need a small trans output flange and a lock ring to run that driveshaft.

you will also not be able to fit a mechanical fan, don't bother. It sits too high on the engine and hits the hood, even if you have room to the rad to fit it.

position 3 will be difficult. you will need more work to get the downpipes around the firewall, and general rear-of-engine maintenance will be inconvenient.

everything else is spot on

Okay, Ill run an electric.
What are the exact benefits and disadvantages of Position 2 vs 3?
I am just pushing for position 3 mostly because of http://www.e30.de/335i/06.htm