MegaSquirt: Sticking it to the man...

[Jon K]

So here I am at school still, nothing to until tomorrow morning when I take my last final exam. Once I am done, I am going home to pick up saj3n's car to do a radiator and struts for him over break. Once back from that, I will put on some music (I am thinking Mendelssohn or Liszt for now) and begin building my MegaSquirt standalone ECU.

Being that I am bored, I decided to look up this Grassroots Motorsport article Bahnstormer had talked about a while ago regarding MegaSquirt. So, here I am reading it, I am about 25% through and realized this is not only informative but also a good read. So, I decided to share with you guys because I know a lot of you are not exactly sure what MegaSquirt is, what it does, and how much it costs. People hear "Standalone fuel management" and think 2- 3- 4 thousand dollars. Wrong. So here is the article - I find it quite entertaining, informative, and motivating

http://www.grmotorsports.com/news/10...megasquirt.php

[winfred]

i am thinking about building a ultra megasquirt for the e30

[Jon K]

The Ultra is not out yet but rumor is that it will be soon. I am using a MS v.3 with MS-II add on card later. Something worth noting is that they yielded 100whp initially with just the MS installed. Once they had it redo the AFR's, it yielded 117whp. The 100whp was +10 on their previous test, and 117, is then, +17 hp, just in a preliminary tweaking. Very nice.

[winfred]

that's why i am still thinking i've been watching for over a year for the ums to come out as i am not in a hurry

The Ultra is not out yet but rumor is that it will be soon.

[Jon K]

is there a specific reason you need UMS over MS-II?

[Booster]

My boss's friend in ST' Louis Mo. has been doing Beta testing with them for some time now. Its convinced him to run Mega on 3 of his cars.3rd gen RX-7,1st gen RX-7 and his sons 2nd gen too ! ALL of them turbo and injected 13B's.
I figure what the hell......I'll do it on one of my Turbo Datsun 240-Z's just to simplify the older 3.0 litre modded electronics that tend to have Gremlins from time to time.
If I like it enough.....I'll do another one for my 525I turbo instead of just a chip and additional injectors. Would be more efficient for sure.
.............Vinny

[winfred]

it's been a while i looked at it and can't remember what pushed my decision to wait for ultra, it was something that caught my attention some feature i want. ill check out the site and see if i remember

is there a specific reason you need UMS over MS-II?

[kyleN20]

to intense for me, i woild def need help on this portion of turboing. but why cant you just use standard FI, it seems like this is for taking a carbed car to EFI, why not just stick with what you have if you already have EFI. and i am truly asking this question, not making any kind of statment.

kyle

[Jon K]

I don't think you fully understand what it does. It is a EFI controller. Our cars already have one, true. The MS is a EFI controller for cars without EFI. But more than that, it is a programmable EFI controller. You plug your laptop in, and with various sensors, are able to dial in more or less fuel/timing/spark. You can use "standard FI" (I think you mean the stock Fuel Injection computer) if you get a chip burned specifically for your application - but few tuners offer that and as far as doing it yourself, you need to know how to read hex code and where in the hex dump the fuel maps are etc.\

The alternative is running a chip - you cannot (although FMU/RRFPR work, as I have right now) just turbo your car flop some big injectors on it and go. The stock ECUs have no idea what happens with boost as they are not MAP activated. They also don't have the necessary fuel maps to be able to scale injector pulse width down. Let's play a numbers game. Let's say 19# injectors on an M30 idle (this is totally hypothetical) 12 millisecond pulse width. You go and stick 30# injectors in to support your boost, the ecu says - based on the O2 readings - "wow this car is running rich" (obviously, larger injectors...) so it tries to make the pulse width as short as possible (amount of time the injector is open) but maybe it can only go to 10 millsecond pulse width, but the car is STILL rich because of higher flowing injectors. The injector size may require a 7ms width, or you may simply have to raise idle to add more air, the ECU, without a chip, is not able to do any of this - it can only work in it's programmed tolerances.

[kyleN20]

muy interesting, do you have to be skilled in computer know-how in order to set up a system like this? like you were saying, with all of these unknown tolerances, its possible that a stock ecu cant down tune it enough, but it would seem to me that making your own ecu would be "harder"?? wouldent having a chip burned for you be cheaper? and when you do set up your own MS system, how do you know yourself what to set pulse width at and such?

thanks for the info

kyle