RomRaider

Hello guys,I am currently building a Frankenstein engine with spare parts I had in my garage.My setup is:
M52B25/28 aluminum block,M54B30 rotating assembly including camshaft,M50 non vanos camshaft.Unfortunately I sold my M50B25 intake manifold with the injectors and the MAF from my old engine 2,8 so I am going to experiment with an M54B30 intake manifold that I got very cheap (80 $ fully equiped).I will convert the electric throttle to mechanical but my question is if there is any chance of making the DISA valve to work?My point was to see if I can keep the low end torque that I had lost with the M50 intake.I will have to tune for the M54 injectors also so any advices are welcome!

I had started doing this about 9 months ago for my 328is.

A few roadblocks you will run into:
-making sure the idle control valve tract will feed into the main port, instead of the turbulence bores. Some custom machining/drilling may be needed. This is the most crucial part of the whole project.
-I know it fits on the block, but you have to make sure everything is bolted on and secured properly. Also the coolant pipe will need some bending.
-CCV system will need to be converted to M54 type
-You need M52tu fuel rail
-I used an M50 throttle body, bored out, and a customized adapter plate
-DISA control is going to be a bit of a challenge... I believe I may have it sorted out, but I haven't yet put it into practice. It would be a rough ON/OFF at a set rpm.

I was thinking of maybe even running this engine on MS42 or MS43... E46 Alpina cars had a single VANOS engine running on MS42/MS43 so it's possible.

You have read my mind again I just started doing this because with ms41 vanos doesn't give me enough control for it (also i need disa control too) So i took apart non-flashable ms41.0 unit and put in ms42 pcp. I only need to solder wires between the pcb and ecu connector. Hopefully i can make it run without ms42 semi drive by wire thorttlebody.

I also have the m52b28 intake modded for m52. I can take pics how it's done if someone is interested.

I should just call you and chat for days


My slight worry with MS42 would be that the Alpina cars actuated the VANOS using the DISA maps (probably just wired VANOS solenoid to the DISA out), so you would have to figure out a way to actuate the cam with the VANOS maps, and DISA with the DISA maps... all while ignoring exhaust cam behaviors.

I don't think you would have too much trouble with the throttle body... although, you can just use the M52tu throttle body if you wanted at this point.

I'm glad to hear that someone else is working on the same idea.I want to use the M54 throttle because it is 68mm and the M52TU is 63.About the DISA all I want is to make it switch in the correct RPM,as enabled said a simple switch.A friend of mine told me that we can make it work with a simple device but I prefer if I can control it with the stock ECU.My first tought was that the swich point is close to the VANOS OFF point so I can wire them together.What about the injectors,do I need to calculate a factor for the different rate and multiply all fuel related tables or just start from the 0 and use the WBO2 to tune?

Well I was working on re-purposing the exhaust flaps output, and have it switch at around 4000 rpm, but I haven't tested it yet. When I was about to test it, we bought a house and moved, so I wanted the car to be operational. Then I didn't resume the work. Busy life .


If you want to use M54 throttle body, then you pretty much need to use MS43 DME, and the whole drive-by-wire system, unless you have some more in depth ways to deal with it.

Can you use the purge valve output pwm tables that some are controlling boost with? 0% Duty Cycle and its off. 100% and its on. Probably need a transistor to step the current up a little but I havent personally played with it.

Seems like the exhaust flap vacuum line would be easiest.

Oh yeah that makes sense I was wondering why the DISA maps on alpina bin looks so weird and they have disabled some vanos DTC's but not disa DTC even thought they don't use disa. But I would say that it's quite hack from Alpina

I may try regular ms42 sw at first and try to disable stuff related to the thorttlebody and exhaust vanos and try to make it run without fault mode. I have tested that the engine runs without the stock thorttlebody. But it's at fault mode and engine is very sluggish. Also if exhaust vanos is not working the engine will go to fault mode. The alpina engine may even run at vanos fault mode normally because the part load fuel injection maps are at zero. Only the vanos fault mode (base) fuel map looks normal.

My backup plan is just to use ms41 and drive the disa using exhaust flap output.

Im almost done assembling the engine,the intake fits perfect with some minor modifications but now I was thinking about the TPS signal.Can I use the M54B30 internal TPS,is it with the same parameters or to use M52TU throttle?What do you think guys?

The issue here for me is the m50 manifold flows more cfm than the M54B30 manifold does
So surely performance will suffer
Also the harmonic balance issues with the M54B30 crank rods cause the pistons to slam into the cylinder walls as well as unwind the oil pump nut

I've seen a few of these done now they don't last long and they don't make much power either
First one I saw made 240hp
Second 250hp nither lasted long lol

Best option is to stick with m52b28 and have the head skimmed and drop a set a cams seen plenty make 260plus hp this way with the right tune

However I'm in process off building a 3.0 myself but going a different route than others will reveal more about it closer to completion

That depends on what cams you have. For me it looks like that at about 6000 RPM the m50 intake flows best of all m5x intakes. So if your cams are close to stock or for example 240 degrees, it gives quite good hp there. But for some reason the m50 intake suffocates the engine past that 6000 RPM so if you have aggressive cams that give most hp on higher RPM the M52TU/M54 intakes for example are much better option. Those flow much better on higher RPM. And also down low RPM where m50 intake sucks big time...

I at least won't be putting m50 intake on anymore. It seems to be restriction even with s52 cams. My next engine will be m52b28 with m54b30 crank and harmonic balancer. s52 cams, m52tu intake and b28 pistons so that I get compression ratio closer to 15:1. I will be using e85 so high compression ratio is not problem.

Itbs then

I would go this route also. Find M3 ITBs for reasonable price, machine out an adapter plate and call it a day. It should be beneficial for throttle response too. But if they get DISA working they'll probably gain mid range torque and get better fuel economy.

Sorry for being off topic tho.

Yep. Muffler Solenoid table is perfect for this. And it's already defined. Tune it the same way you tune VANOS. Overlay HP or Airflow against RPM with DISA always on and always off. Then enable those cells where the HP or Airflow curve is higher.