Video: MegaSquirt running on BMW M50

[SoStock92]

Please right-click and save the AVI file to your drive, because AVI files don't stream there is no point in trying to open it right up in WMP.

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This is a BMW M50 motor running 3 GM coil packs in wasted spark with custom length MSD Helicore wires and stock spark plugs. The idle fluctuates a little bit because of the stupid idle control valve - that's coming out today or tomorrow

So, here it running! Yesterday when I posted, I had run the car until it was warm then quickly swapp the stock coils out loaded the plug wires and GM coil in and hooked her all up checked the settings cranked and it ran. But we all know it's easy to get a hot motor running, the real test is whether or not the thing will start when "cold".

It was 72 degrees this morning when I went out to get the video for you guys - I had never started the car from cold start on ignition control yet, so I was sort of not sure what would happen. I adjusted the "warm up" settings and cranked her up. Fired over right away!

I mentioned yesterday a great find that would have M50 NON VANOS users smiling wide. This is my daily driver and therefore I cannot pull the motor apart and mess with it because I usually need it if not the next day, 2 days from then. So, I have another engine in my garage (M50 NON VANOS) that everyone knows I am building - so I have been trying to figure out the crank trigger angles by using that motor. Well, since I broke the engine down and the crank wheel is off the crank, the crank out of the block, etc etc etc, it didn't cross my mind to check the TDC marks relative to the crank wheel.

I had been using an image provided by a guy from an E34 website as my reference which clearly shows the missing teeth on the crank wheel at about 10 o'clock when the motor is at its "TDC" mark. However, I noticed that the location of his TDC mark on the crank wheel and my TDC mark on the crank wheel are physically different in location - his on the face, mine on the edge of the wheel. I had been using his picture to try and formulate the crank trigger angles for megasquirt and was having NO success. The thing kicked back on the starter, etc - bad things were happening. Then I went over to my garage and just held my spare crank wheel up to my spare timing cover and saw that the TDC mark leaves the gap in the teeth on the wheel at about 1 o'clock or 2 o'clock... which is similar to the E30 M20!

I went home started talking to my MegaSquirt M20 friends and one of them had a pic of their crank wheel marked up and at relative TDC. Turns out, if I am looking at it right, the M50 NON VANOS and the M20 crank wheels are the same positioning! The CPS is at tooth ~15 on both motors, this means that M50 NON VANOS motors should accept the M20 crank angles in MegaSquirt. But, this was theory and I had yet to try it.

So I continued to think and think (over thinker, I am) and then at work just decided to put the M20 numbers in there and throw a crank timing of like 5 degrees advance and 7 degrees idle advance just to see if it'd kickback on the starter like it did before when using what I THOUGHT was a pic of an M50 at TDC. The end? The bitch fired right up and it freaked me the hell out!

Turns out the picture that guy sent me was of a M50 VANOS motor which has different crank wheel positioning at TDC which really doesn't matter, but it was confusing as **** because you have to count the crank angles differently and was confusing me.

I have to go over to the garage I work out of and get my Bentley manual and some other tools (car is here) and remove fan clutch/etc and set motor to TDC and make new markings on the engine somewhere and confirm that the timing MegaSquirt is seeing is the same as the motor.


Confirmed the timing on the motor and I believe it to be dead on

Here are the images. It looks like I got it lined up pretty good.






So hard to set this motor to TDC with the fan/shroud in place... very annoying so I set the motor to TDC with a mirror and digital camera and then made duplicate TDC marks on the oil pan that I can see when I get on the ground w/ timing light.


By the way this is a first, never done before on a BMW M50 motor Up next? Safe tune and mad boost

[SilverTurboRidin]

nice work man ...very extensive write up which is always good!

[sisforsurfing]

Awesome to hear that worked out. Are you planning on boosting that engine or the one sitting in the garage? Regardless, tuning should be lots of fun. That's great you're the first M50 to run the MS... they said it couldn't be done, haha

[99SL2_Modder]

I always find it weird that people constantly talk about using a setup with wasted spark...but then again, I guess that's because my car uses it stock. =/

[Black Power]

Originally Posted by 99SL2_Modder

I always find it weird that people constantly talk about using a setup with wasted spark...but then again, I guess that's because my car uses it stock. =/

yeah, but you still have a saturn

[SoStock92]

Originally Posted by 99SL2_Modder

I always find it weird that people constantly talk about using a setup with wasted spark...but then again, I guess that's because my car uses it stock. =/

99% of cars on the road use wasted spark - the point is that it's easier than sequential spark control and everyone told me how difficult it'd be to get a BMW motor with its trigger angles/etc to run on MS.