RomRaider

Hello

Thank you all for the effort you have put into this project. I am incredibly excited for the custom code in the works and am looking forward to contributing as I believe it will be very useful to many people! Now to my current silly project idea:

I have seen m20's on m50 management in the past, but I would like to try using MS41. Here is a fun thread for reference: http://e30techarchive.com/showthread.php&t=63504.htm

Couple questions:

Would this cam trigger work, or will I have to make my own trigger wheel similar to the native 50/50 wheel? https://bimmerheads.com/products/cam-sensor-plate

I figure either way I will adjust the trigger position until logs show cam timing to be close to a stock S52.

My second dilemma is the crank pulley. See here: http://m54megasquirt3.blogspot.com/2011 ... tings.html

I plan to get it idling with an s52 crank pulley as proof of concept (with euro front mounted crank sensor), then I suppose I could try an m20 pulley by adjusting the base timing map by 240 degrees? I'm not sure if the DME code will accept timing valves that far out of expected range, but it would be nice to use the m20 pulley so I don't have to try and convert to a serpentine belt.

Assuming I can get this thing to run well N/A, I would like to turbocharge it. I thought it would be cool to use the VANOS wire to trigger a meth relay, utilizing the fuel and timing "VANOS" correction maps, however I am hoping I can simply disable the "VANOS jammed mechanically" fault because obviously my cam won't advance.

Thanks in advance for your feedback!

The effort and expense of doing this, you'd be better off just going MS2/MS3 like most people with M20s do.

Or speeduino which is lot cheaper than even ms2 and easier to wire.

I'm not worried about cost or effort... I've used megasquirt on m20's, but I want to try something new. If you read the link I posted, people are able to run m20's with m50 bosch ecu's easily. I'm comfortable with romraider and ms41, it has all the features I am after, and I already have the parts needed. Besides, if it doesn't work, I will be using the e36 harness anyways for the prewired sequential fuel and spark and I'll just use a PnP e36 MS unit.

Cool idea! I was amazed to read how easy the M50 (Non-vanos) DME can be used.. It will probably be a little harder with the MS41 as the crank wheel isn't the same (M20 and M50NV are identical, which makes it a lot easier), but I think it's doable. You can first start off without the camshaft sensor wheel, as it's optional (you'll loose seq. injection and it will resort to wasted spark), but it will still be a major improvement over the M20 DME.

I think the MS41 is a quite advanced DME. As MS2 only allows 4-channel seq. injection, to get a comparable Megasquirt DME you'd need the MS3, which is quite expensive. You can get the MS41 DME and wiring harness for a lot less money.. I've megasquirted an E28 528i before (MS2) and costs easily go in the direction of $1000 USD. MS3 a bit more expensive. To properly tune the M20 you'd need a wideband O2 sensor though, so that will increase the costs a bit.

I was playing with the thought of using an M50 DME to upgrade the E28 528i, but eventually decided to go with Megasquirt.. Back then I didn't know (or perhaps it wasn't even available then) about RomRaider and the MS41 DME.

For your info: The M30B28 in the E28 528i really, really loved the upgrade (wasted spark instead of distributor, AFM-delete, way improved digital ignition curve, I used M50 injectors instead of the old L-Jetronic injectors).. Acceleration 0-62 mph went from 8.4s stock to 7.0-7.2s .. It turned into a quite fast car, big smiles.

So, if your M20 is still the old L-Jetronic you can really expect major gains. If it's Motronic, which was a major improvement of L-Jetronic due to the way improved ignition curve, you can still expect moderate to good gains (AFM-delete, improved tune, stronger spark due to no distributor). Also depends on if you compare it to a stock Motronic 1.0-1.3 DME or a tuned Motronic unit. Compared to tuned Motronic unit (which already has optimal fuel and ignition maps), gains will be moderate (better air flow and throttle response due to MAF instead of AFM and better spark). Other advantages are the ability to log and the feedback/errors the DME can give you compared to the simple Motronic units.

Good luck! I certainly think it's doable.. Let us know the results!