I need a MegaSquirt!!!

Discussion pertaining to positive pressure E28s.
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5timesturbo
Posts: 265
Joined: May 26, 2013 3:24 AM
Location: Fayetteville, Ga

I need a MegaSquirt!!!

Post by 5timesturbo »

I need the easiest or quickest or best route to a MS system on my turbo e28. I reached out to someone to make one for me and it has not materialized as they said it would. Can I get some advise? Can someone point me to a manual on how I cam MAKE my MS system. I'm pretty technical....or I'll pay for someone else to build one. I just need one in a the next month. Please tell me what I can do brothers.

-Thanks.
RossDinan6
Posts: 57
Joined: Jun 24, 2006 11:23 AM

Re: I need a MegaSquirt!!!

Post by RossDinan6 »

Sounds to me, by your post, that you need to hire an experienced calibrator. You claim to be "technical", but What does that mean?

Trust me, stand alone engine management can not be rushed.
Nosis
Posts: 311
Joined: Nov 25, 2009 11:38 PM
Location: Denver

Re: I need a MegaSquirt!!!

Post by Nosis »

Ehhh. If you’re not already running motronic 1.3 you have a lot of wiring to do. If you do already run 1.3, https://www.diyautotune.com/product/me ... -e30-325i/ will save you the ECU assembly effort, but at substantial cost. And you will still need to rewire the harness for timing, IAT, and wideband O2, at least. I’m not sure if the PNP ECU even has 3 coil drivers in the ecu , so if you want wasted spark you may have to open it and mod it anyway... t here is no reason not to go wasted spark from this point so add wiring for 3 coils, a coil pack and plug wires.

My .02c of the reality of MS is that you really only have one choice, the best route. It involves converting to the motronic 1.3 60-2 wheel and sensor, and building a new wiring harness that either uses a bosch 55 PIN plug and a PNP ECU as linked above, or use the DB37 plug that comes with the generic Megasquirt 2 kits. In either case, you have a ton of learning and tuning to do, after you’ve opened the engine harness and made all the wiring changes. The AFM goes away, so you need the GM IAT sender, Megatune can use any CLT with known values so stock is fine.

My used TCD came with a megasquirt DIYPNP, and I already ran motronic 1.3 on my b35. I ended up rewiring and repinning many connections to clean up the install and add intercooler pump control. And that was just hardware. The tune is a whole other issue, but the resources are here. Almost a year later I am still ironing out tuning issues but seldom drive the car, I’m not sure it would be doable for me on a daily driver, but mye28ers do it every day.

I just ordered a MS 2 kit for my NA 533i and am going to follow my own advice. It will take effort to build, but I’ll be sure it is setup how i need it... and since i have to make a whole harness anyway, no need to look for a ‘super eta” harness for PNP purposes, even though thats what i'm going to butcher off and use the db37.

MS is a labor of love, and lots of fun. Don't get cheap, buy megalogviewer. You will be able to get a base tune but do get familiar with the megamanual http://www.megamanual.com/ms2/tune.htm
5timesturbo
Posts: 265
Joined: May 26, 2013 3:24 AM
Location: Fayetteville, Ga

Re: I need a MegaSquirt!!!

Post by 5timesturbo »

RossDinan6 wrote: Nov 12, 2020 10:40 PM Sounds to me, by your post, that you need to hire an experienced calibrator. You claim to be "technical", but What does that mean?

Trust me, stand alone engine management can not be rushed.

Hey man, I’m not gonna argue with you over how technical you believe me to be...lol. I just wanted To ask the different pathways to realizing a MS on my boosted e28
marc79euro645
Posts: 445
Joined: Dec 09, 2008 12:33 AM

Re: I need a MegaSquirt!!!

Post by marc79euro645 »

If you can install a car stereo, you can wire a MS. It does require a lot of reading, to set up , but there's a lot of help here if you have problems.
RobertRO
Posts: 370
Joined: Feb 12, 2006 1:00 PM
Location: Romania
Contact:

Re: I need a MegaSquirt!!!

Post by RobertRO »

If it is of any help, here's a briefing of my Megasquirt build story:
https://www.bimmerforums.com/forum/show ... my-E32-M30
(note: all the links to the pictures work, even if sometimes they don't get loaded in the forum page. You just need to right click on the picture symbol --> open image in new tab).

Although my application was for a Motronic 1.3 wire harness, you can easily adapt it for a Motronic 1.0.

I would like to stress on what Nosis pointed out above: building the ECU it's rather easy. It's the tuning where the pain waits. Do not underestimate it.
Quite odd, tuning the high load it's rather easy. You can get good results, fast - as long as you start on the safe side, and improve in small, controlled steps. Idle and warm up tuning, they are more challenging, but doable.
I found most difficult to and/or I still have to work on:
- determine the correct injector dead time (note: the dead time changes with battery voltage, but also with the temperature of the injectors). Actually, I found this parameter to be of major importance. Start with a bad dead time, and it will induce headache all over;
- smoothing out transitions and low trottle cruising;
- reach the right MAT/CLT Correction and MAT Density Table;
- eliminate the influence of large ambient temperature changes on the quality of the tune.

Unless you have plenty of time to invest in this, you will never get nowhere near the superb tuning of a stock ECU.
But, at the same time, if you heavily modify an engine, then Megasquirt offer a good solution to reasonable tuning.
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