Ecu Options

[Jayzzle]

So, I'm planning some ridiculous things for my battered old E30. I know I'm getting way ahead of myself here but, I'm really just looking into things atm so when it comes to actually doing it i can have it all planned. I would like advice/suggestions on stand alone ECU options for an M40B18 which will eventually have a turbo on it. I have read a few things on various forums and they all mention MS standalone because it's simple to install, does anyone have any thoughts on this? Can anyone suggest a better option? Thanks guys. I'm looking forward to reading your input.

[Guest Mister Dabsy]

It's a great question... Not come across anyone doing that to a BMW four-potter ! Might be less painful if you threw a straight-six in her ;)

[Jayzzle]

It might be, but I have convinced myself to do an M40, my reasoning is that hardly anyone see's it as worth it, preferring M42s or M20s. I heard a lot of bad things about tuning an M40 but I wanna see for myself. Plus it's just going to be something to mess about with anyway, it probably won't ever see the road again when it's finished (unless it's lucky :P)

Actually Dabs it was your manifold idea that got me thinking about turbos and that led me onto ecus and all-sorts, so.. Thanks :D

[Guest Mister Dabsy]

Hahahaha I'm an expert at theology, the practical shite comes from busting my knuckles trying to undo 14mm nuts with substandard tools :rolleyes: :lol:

[Jayzzle]

Yeah I know that feeling all too well mate ^.^

[Guest DazH]

It might be, but I have convinced myself to do an M40, my reasoning is that hardly anyone see's it as worth it, preferring M42s or M20s. I heard a lot of bad things about tuning an M40 but I wanna see for myself. Plus it's just going to be something to mess about with anyway, it probably won't ever see the road again when it's finished (unless it's lucky :P)

Actually Dabs it was your manifold idea that got me thinking about turbos and that led me onto ecus and all-sorts, so.. Thanks :D

The power gains from the M40 once turboed and Megasquirted really are not impressive if you look at the raw stats and do the math. Anyone who says MS'ing is a doddle, no longer has an engine with a cylinder head on it IMO.

I really don't advise yammin' a turbo onto a 23 year old 4 potter without any internal modifications.

As Dabs said, if you want to do something that is WORTH while, drop a straight six in. You have the following options

- M20 which would be the M20B25 small block straight six

- M50 which you would try for the M50B25 like me (just taking my time with it). Non-Vanos preferred for Turboing

- M30 which you would try for the M30B34 big block. Although still SOHC, this engine was never dropped in so its quite a tasteful transplant IMO

Hope this helps

Daz

[Jayzzle]

Hmm, you have given me a lot to think about. I was really excited about messing about with my M40. I wasn't planning to just leave the engine as it is. But I'm starting to have doubts now as I find more and more problems surfacing. They are all minor problems and simple fixes (I think), just time consuming. The plan was to just gut it completely, and change a whole bunch of things. But I got pretty into the idea of rebuilding the M40 and having the car with the original engine still, I know it wouldn't be that much quicker, but it was just gonna be a project for me to see if I could do it. I dunno, I realy like the idea of doing it to the M40, but I do quite like the idea of a 2.5 straight 6 too.. Trouble is if I had an engine like that, I'd only really wanna do 1 thinig with the car, and I don't know if this old shed of mine could take that kind of punishment.

[Guest DazH]

Hmm, you have given me a lot to think about. I was really excited about messing about with my M40. I wasn't planning to just leave the engine as it is. But I'm starting to have doubts now as I find more and more problems surfacing. They are all minor problems and simple fixes (I think), just time consuming. The plan was to just gut it completely, and change a whole bunch of things. But I got pretty into the idea of rebuilding the M40 and having the car with the original engine still, I know it wouldn't be that much quicker, but it was just gonna be a project for me to see if I could do it. I dunno, I realy like the idea of doing it to the M40, but I do quite like the idea of a 2.5 straight 6 too.. Trouble is if I had an engine like that, I'd only really wanna do 1 thinig with the car, and I don't know if this old shed of mine could take that kind of punishment.

Do what you think is best.

Maybe just.. rebuild the engine you got? No need to mess around with blowers or ECU swaps, just good ol' fashion rebuild to make her run smooth as anything.

Please bare in mind that, once you start messing around with the engine, expect her to be off the road for some time. IF you have never done a job like that before, do not expect her to go back the way she came apart and just, fire. Everyones human so you learn by making mistakes.

Either way, you have all of us behind you as a team.

Daz

[Jayzzle]

Maybe just.. rebuild the engine you got? No need to mess around with blowers or ECU swaps, just good ol' fashion rebuild to make her run smooth as anything.

I think that this, will be my best option, I guess I can just get another car for a "go faster" car. Does that mean that you don't rate aftermarket Ecu's on stock everything else? I thought that even without changing anything else an upgraded ecu would make the car run better, is that not the case?

Please bare in mind that, once you start messing around with the engine, expect her to be off the road for some time. IF you have never done a job like that before, do not expect her to go back the way she came apart and just, fire. Everyones human so you learn by making mistakes.

Yeah I expect it will be off the road for a VERY long time, partly because I haven't done it before, and partly (mostly) because I'm lazy lol. I am looking forward to it though, I expect it will be a very educational and challenging experience, and hopefully I can see it through from start to finish.

Either way, you have all of us behind you as a team.

Thank you, you have all been such a big help to me already. With the overheating problem and the Exhaust and that, I really appreciate it. I can see before the end all my constant questions will become annoying haha :P

[Guest DazH]

Yeah you can mess around with after market ECUs if you wish but you shouldn't if you don't have an actual understanding of the major concepts involved. I was forced to get a good grip on Motronics due to my engine swap (Move from L-Jetronic to Motronic injection) and without doing what I'm doing, there is no way I would know half the stuff I do now about it. Messing with ECUs yourself is something I wouldn't take lightly.

There are plenty of companys that take it upon themselves to be specialists in that field. Maybe speak to one of those.

Keep the questions coming mate. The people who are answering your questions genuinely get a kick out of it like a dirty mechanical fetish :rolleyes: All we/they ask in return, is a pint at the next meet lol :lol:

Daz

[Jayzzle]

I read some stuff about the ecu on the MS website and they say that a lot of them are just plug and play, but then I guess it all depends on the engine setup really. I think then that if that is the route I take I will get a shop to do it rather than to buy a DIY kit. Unless I do some extensive research first.You mentioned you were in the middle of an engine swap, what are you swapping for what and how far have you got? I would love to come to one of the meets, but not in the shed I drive atm, at least not while it looks so bad, that would be embarrasing being seen in it whilst surrounded by the cars I have seen in signatures on this forum lol.

[Guest DazH]

I read some stuff about the ecu on the MS website and they say that a lot of them are just plug and play, but then I guess it all depends on the engine setup really. I think then that if that is the route I take I will get a shop to do it rather than to buy a DIY kit. Unless I do some extensive research first.You mentioned you were in the middle of an engine swap, what are you swapping for what and how far have you got? I would love to come to one of the meets, but not in the shed I drive atm, at least not while it looks so bad, that would be embarrasing being seen in it whilst surrounded by the cars I have seen in signatures on this forum lol.

I have a mint '87 E28 5 series and putting the engine from my 91' E34 5 series.

M20B20 SOHC --> M50B25 DOHC

I have the M50 engine almost completely rebuilt. The top end is complete and waiting to be put ontop of the block. The block is about 3 hours away from completion as I've just finished reconditioning all the pistons. The M50 is sitting on an engine stand next to me as I type. ALL parts replaced apart from main drive components. The total spend so far is £2 grand.

All I have to figure out now is the correct positioning off the transmission linkage as I'm using the M20 manual transmission along with the SM Flywheel and to wire the new Motronic system into the E28 getting all sensors to talk to the dash which is no easy task as the M50 engine uses different technology.

Also having a complete customer 3" stainless steal exhaust fitted with electronically opening headers. Beauty of the EARLY M50 (Non-Vanos) is I have no lambda sensors or cat to worry about :) Like yours, a big tube tube but, in my case.. soon to be 2 tubes split into 4 at the rear HAHA :rolleyes:

If you need any advice, I can help as I through myself into the deep end. I've had to work out all the complicated bits it going into a RHD vehicle.

Daz

[Jayzzle]

Ahh that's nice man, has it taken long to get to where you are?

See this is the problem I have atm, after taking the exhaust off (again) there is only one mounting bracket and that is failing too. Everyone starts with mint cars already or decent at least, I have (once again) bought myself a !Removed!. It's just becoming an endless list now of stuff that needs rectifying.

Does that mean, that I can convert my single pipe into a twin pipe? And, if that's the case, is it better to have smaller twin pipes to a larger single pipe?

Did you make the exhaust yourself? Dabs suggested I have a bash at making a 4 brancher, which I thought was a really good idea and I really wanna have a go at it. Trouble is, my welding skills leave a alot to be desired. For instance, I recently welded my exhaust from the downpipe back, and most of the weld joints leak so... Yeah. But to be fair, that's the first time I have ever welded anything and it was only leaking a little bit from each joint :D I have taken it off again to re-weld it. Hopefully it will go better this time lol. But s for the manifold, I can at least get the majority of it done and leave the welding to a Pro. The only thing that is left to decide on that front is 4-2-1 or 4-1 ^^

So your 91 5 Series is a LHD? I always wondered what it would be like to drive a LHD.

Is the Motronic system from the donor car or is it a new unit? Will it just connect up nicely or have you had to do a lot of modifications to the loom?

Will it be much quicker than the M20? What inspired you to change the engines?

Thanks man.

[Guest DazH]

It's taken me about a year to get where I am now BUT... that is because I've had a lot of things going on in my life that ahve taken priority. If your dedicated, you can get it done ALOT quicker then I have and so could I if I had dedicated more time.

The M20 is ALOT easier to swap as the E30/E28 both came factory with it. The mounts are in the right place and the transmission literally just bolts right up. The M50 was never put in either the E30 or the E28 so it is much more difficult. The E34 was RHD but the engine bay was designed to cater for the larger head of the M50 (DOHC) so the problem you get when you put it into the E30 or the E28 is that it sits at a different angle (15 degrees or so) to the O/S. This causes a problem with: A: The transmission mounts. B: The engine mounts. C: the Exhaust manifold being pushed up against the steering box (Hence easier to do if the car was LHD). You also have to consider the Intake is bigger therefore it often sits too tight to the brake booster/servo. I am yet to see if I will have the brake booster issue but if I do, I'll deal with it there and then. "They" say I can use a booster from a Porsche 944 or a Renault Clio... We'll see in a few months when I drop her in.

I haven't made the exhaust yet but I probably will. I'm not the best welder either but fortunitly, I know loads of welders who can defo help me out. The hardest part is bending the tubes. A lot of thought must go into this as if you bend it in the traditional way, you will narrow it at the bend therefore creating nasty back-pressure and all sorts of problems. I think I might stencil it out, do the math then get a professional to do the bending for me in sections. I'm going a step further with mine as I'm having quad exhausts out the back. Unlike the M20 enigne, the M50 manifold has TWO flanges so the plan:

two down pipes --> Electronic cut-out valves x2 --> Silencer x2 --> one pipe goes to N/S back box and other goes to O/S back box --> Spark plugs in tips to spit flames

Bare in mind, this is only really possible if you remove the spare wheel space which, I am. Chop and weld a plate down there.

Should look something like this:

I'm not to sure if 2 pipes would be better then one big one. Maybe someone else will know...

​Motronic system is easy enough to implement as it runs from the ECU but, the ECU on the 525i E34 is positioned differently so I have to drill through the bulk head to get the ECU to sit inside the E28. The most common place is the glove box but I think I might put it under the front passenger seat.

What inspired me to do the engine swap?

I blew seven shades of shite out of the M20 engine that was in it already and BMWOC helped me rebuild it. I had so much fun rebuilding the M20 that I knew I couldn't stop there. Also, try find an M50 converted E28 that is RIGHT HAND DRIVE LOL hens teeth mate. I only know of one that has been documented and look at the state of it!

Daz

[Jayzzle]

I think it will take me a lot longer than a year tbh lol. I'm not very "have at it" anymore. That sounds like an awful lot of work to do for that engine, Will the rewards be worth it?

I rewelded that exhaust earlier, and actually it didn't turn out too badly, I even managed to get my oval pipe on instead of that fugly round thing. I still have a slight leak but a bit of fire putty fixed that. Now it sounds lovely, I was worried when I first put it on a few weeks back because it was so loud, that's why I ended up with the massive round monstrosity, but with that rather lucky find of the middle silencer, it sounds gorgeous with the oval on. That exhaust plan you have sounds mint, I bet it will sound lush too. But, the spark plugs in the exhaust, is that safe? I've heard of it before but always thought it could make the car explode or something lol. If that's what the underside of your car will have on it then it will look amazing, and the angled twin pipes at the end look really good too, I can just picture what it would look like on my car in my mind lol.

If I was to put an m20 would I need to change the ecu too? Or would it work with the one that's in it?

It does sound like you are having fun while doing it, and I think I would too. It's just finding the time to be able to take it off the road for an extended period of time.

[Guest DazH]

I think it will take me a lot longer than a year tbh lol. I'm not very "have at it" anymore. That sounds like an awful lot of work to do for that engine, Will the rewards be worth it?

I rewelded that exhaust earlier, and actually it didn't turn out too badly, I even managed to get my oval pipe on instead of that fugly round thing. I still have a slight leak but a bit of fire putty fixed that. Now it sounds lovely, I was worried when I first put it on a few weeks back because it was so loud, that's why I ended up with the massive round monstrosity, but with that rather lucky find of the middle silencer, it sounds gorgeous with the oval on. That exhaust plan you have sounds mint, I bet it will sound lush too. But, the spark plugs in the exhaust, is that safe? I've heard of it before but always thought it could make the car explode or something lol. If that's what the underside of your car will have on it then it will look amazing, and the angled twin pipes at the end look really good too, I can just picture what it would look like on my car in my mind lol.

If I was to put an m20 would I need to change the ecu too? Or would it work with the one that's in it?

It does sound like you are having fun while doing it, and I think I would too. It's just finding the time to be able to take it off the road for an extended period of time.

You would need to change the ECU you have already for the M20 one, Yes.

That picture doesn't portray exactly what I plan as I'm having twin back boxes but, you get the idea.

I'm not looking for my car to be incredibly fast or anything, I'm doing it really for... well... doing sake. The only way you learn is to get stuck in and I couldn't of got stuck in more.

To do an engine swap yourself, you really have to WANT it. It's a big decision not to be taken lightly

[Jayzzle]

Yeah I can imagine, I would love to do it, just for the experience if nothing else. I have always been into cars far more than anything else, and so far nothing has curbed my interest.