Megasquirt NA Setup?

[MrMuddle]

Hi All, just wondering if anyone can help. I'd like to get around to fitting my Megasquirt2 ecu to my '96 E39 528 and just wondered if anyone had done similar and what you did about the wideband? My long term plan is a boosted setup, but at the moment I'd just like to start playing with the MS2 on the bimmer. As the E39 manifold is split into two and I believe has 2 O2 sensors before the cats, I was curious what others had done.

I currently have 1 Innovate MTX-L wideband controller/gauge but I dont really like the idea of just fitting it to one downpipe for 3 cylinders and not getting a WB reading for all 6 cylinders.

Is there a recommended distance from the exhaust ports for the cat(s) to be, so could I maybe remove the 2 cats and just replace with 1 cat a bit further along the exhaust and fit the WB just before that cat. I know I could just buy a second WB and run a dual WB setup, but wanted to see what the 'norm' was first!

Thanks in advance
Rob

[pizzaman09]

I have played with the MS2 and MS3 though in an entirely different application, single cylinder Briggs and Stratton engines. So I am not expert on the subject.

From a tuning standpoint, you are going to want to run both O2 sensors if it is an option because it gives you ever so slightly more control over the actual output. If you have both sensors the MS2 should allow you to fine tune AFR for each bank of 3 cylinders. The difference probably wouldn't be big but it might help things out a bit. If BMW was doing it with their ECU then there must have been a reason, I suspect you will get slightly more consistent AFR readings with the dual sensor setup.

The Innovate MTX-L wideband gauge is very nice, that is what I was using on the Briggs and Stratton to fine tune the different carbureted setups I was running. I honestly don't remember how the O2 sensor hooked into the Mega Squirt unit, I want to say you didn't need the gauge, then again I am sure you have already figured that bit out. It has been a few years since I played with that stuff.

Good luck and let us know how it turns out! The MS2 is a very powerful and nice ecu that has a considerable tuning potential if you are capable of figuring it out.

[MrMuddle]

Thanks very much for the reply. Yeah I've done a fair bit of tuning with MS so know how to use it, I was just wondering really whether other people running NA setups on standalones alter the exhaust to a single O2 setup or stick with a dual O2 setup. I guess some people may just use one, but I wouldn't be happy just getting a reading from just 3 cylinders, as potentially I may not know if there was an issue with one of the other cylinders just from the AFR reading.

I would quite like to change the exhaust anyway, so I guess I was really looking to know if people have changed from dual to single cat/O2 setup or if people only change the exhaust system after the cats! If people have changed to a single cat/O2 are there any guides or best practices for where to place the cat. Most the stuff I've read online seems to imply the further back the cat the longer it will take to heat up and do it's job but I'm not sure if this is the only real factor. On previous cars I normally remove the cat, but I'd quite like to keep at least one on the E39.

Cheers
Rob

[pizzaman09]

This is just a guess, but I bet you will find the most support in the engine swap section or FI section of this forum because those people are the ones playing with things like the MegaSquirt.
http://www.bimmerforums.com/forum/fo...rced-Induction
http://www.bimmerforums.com/forum/fo...ne-Conversions

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I also remember there being an excellent forum elsewhere just for the MegaSquirt community.