M52 management options??

[93supercoupe]

I just pulled the trigger and got my self a 96 m52 with harness and dme. My e30 alreasy has a diypnp MS.

Ive been reading alot about dme flashing and i really wanna stay away from it.

So what are my options to tune this engine my self? It is going to be boosted.

Can i use my MS that ran my old m20?

If i convert it to obd1, are there programs that allow me to tune it?

Ideally i would like to have a maf-less system.

Most of my research ends at "getting flashed" and doesnt go into much detail about my other tuning options.

[nando]

you can use the MS but the DIYpnp part doesn't really help. I'd sell it and get a different MS kit tailored more towards an M52 - I don't know if whodwho ever came out with a PnP for the 24v motors but it would be worth asking him.

[Cyrix2k]

You can probably use the majority of your M20 harness to run the M52. There is no PNP MS for the 24v engines - mostly because the DME connector is not available in small quantities (like under 100k units). At this point you can use the existing MS with the M20 harness (which is what I would do), use the existing MS with a new harness, or move to another MS (MS3, because otherwise I'd just keep the existing unit) with a new harness. MS3 will give you full sequential spark & fuel injection, but otherwise the older MS2 and even MS1 will do a fine job running the M52. The older units batch fuel injection like the M20 and only need a crank signal to operate - just leave the cam sensor unplugged. This is why the M20 harness will work - the alternator & starter are wired the same, the provisions for six injectors across two channels already exist, and it uses the same crank sensor. I believe all the plugs are the same style so just plug it up & go. The one issue you will need to work out is ignition - the M52 came from the factory with distributorless ignition (DIS). The PNP probably fired the original e30 coil that worked in conjunction with the distributor. You either need to add wasted spark (which I think is possible to do with a PNP provided it still has a regular MS board internally) or another ignition solution, like Ford EDIS. If you're planning to tune the car yourself, this shouldn't be a big issue. It's best you start learning how everything works now, rather than later. If you use an outside ignition module like EDIS, or use the GM coils, just run spark plug wires & eliminate the factory M52 coil packs. The wires fit just fine although they don't look as clean. You can also fire VW coils directly from the MS outputs iirc & they pretty much bolt up.

[nando]

the problem is he has to add a way to fire the 6 coils, it will still take a lot of mods to MS and the harness - I don't think it's worth doing, especially if you're stuck with batch fire and wasted spark.

I guess he could use GM wasted spark coils and just run plug wires. Seems half baked though, when something like MS3 could drive everything directly with the stock harness.

the connectors are hard to get, unfortunately. I got a later Siemens DME connector (for MSS54, MSS45, etc) as a free sample but I can't buy more. :(

but, you can gut one from an old DME..

[93supercoupe]

Awesome. I already converted my m20 to a wasted spark COP, using the good GM truck coils. I have the m52 harness, but i see some cut ends and its missing some loom so id rather not use it. My m20 harness is in perfect shape and already has the provisions for the cop.

My next question is

I can get a 1993 325i m50 swap for 450. Comes with everything EXCEPT the harness. I know ill need the intake mani and tb, so should i buy it? It seems cheap enough to keep it for a back up. Good deal or no?

[93supercoupe]

Heres a pic of the car/setup. I can fabricate another coil bracket to it look decent as i did for the m20

[Cyrix2k]

Awesome. I already converted my m20 to a wasted spark COP, using the good GM truck coils. I have the m52 harness, but i see some cut ends and its missing some loom so id rather not use it. My m20 harness is in perfect shape and already has the provisions for the cop.

My next question is

I can get a 1993 325i m50 swap for 450. Comes with everything EXCEPT the harness. I know ill need the intake mani and tb, so should i buy it? It seems cheap enough to keep it for a back up. Good deal or no?

Given that you already have the COP setup, I'd go ahead and try to use your existing harness.

The m50 sounds like a decent deal if it runs well, but it's not a screaming deal. I paid 6 or 700 for a full e36 and 300 for an M50TU before that.

the problem is he has to add a way to fire the 6 coils, it will still take a lot of mods to MS and the harness - I don't think it's worth doing, especially if you're stuck with batch fire and wasted spark.

I guess he could use GM wasted spark coils and just run plug wires. Seems half baked though, when something like MS3 could drive everything directly with the stock harness.

the connectors are hard to get, unfortunately. I got a later Siemens DME connector (for MSS54, MSS45, etc) as a free sample but I can't buy more. :(

but, you can gut one from an old DME..

Eh, full sequential isn't that helpful imo. There's some efficiency gains but at the cost of a more complicated setup, tuning, etc and no real power gains. Since he already has a good harness & ignition setup, it seems like he's good to go. And it's not like the older MS couldn't be adapted to drive stock coils through the M50/M52 harness. I do I have plug wires on my M50 turbo car and yes, it looks half baked. It runs fine and I did it because I upgraded from an M20 with wasted spark, just like the OP. I believe the GM truck coils are better than the BMW coils???

[nando]

I didn't realize he had the GM truck coils. I have the same ones - they're pretty badass. :D

Sequential fuel does make a big difference though especially with larger injectors. Not in power, but overall driveability and smoothness. it just runs better. tuning it isn't any more difficult..

[Cyrix2k]

I didn't realize he had the GM truck coils. I have the same ones - they're pretty badass. :D

Sequential fuel does make a big difference though especially with larger injectors. Not in power, but overall driveability and smoothness. it just runs better. tuning it isn't any more difficult..

I haven't gone the full sequential route yet, but I meant tuning is more difficult in terms of individual cylinder trims if that is taken advantage of and of course the additional cam sensor setup although that is set & forget.

[nando]

it's not really more difficult - you need 6 EGT sensors or multiple widebands to even bother with the cylinder trims anyway. cam sensor is no big deal either - plus the M52 already has that taken care of. :)

I'd thought about doing multiple widebands/EGTs and doing individual fuel/spark trims but.. meh. :p

[93supercoupe]

The gm truck coils are pretty sweet but the batch injection im not a big fan of.

Are there any factory based diy tuning options? Or is it all flashes when dealing with the stock dme?

[Cyrix2k]

You can convert to OBD-I and then use a Moates Ostrich II to tune live.

http://www.moates.net/ostrich-20-the-new-breed-p-169.html

[nando]

The gm truck coils are pretty sweet but the batch injection im not a big fan of.

Are there any factory based diy tuning options? Or is it all flashes when dealing with the stock dme?

pretty sure you can do semi-sequential fuel with the microsquirt based DIYpnp - which is about 90% as good as full sequential.

[93supercoupe]

What software would i use with ostrich? And im assuming i would have to solder in a socket in the dme?