puppyslaughter

hey can someone give me a good explination of the megasquirt stand alone system and how it works on a FC i am seriously considering doing this but i have a few questions first does it need to be hard wired or will it mount in the old ecu case so i can utilize the plugs from the case so i dont have to cut wires? next how good of a laptop do you need in order for the thing to datalog and what not also which version is the best for a 87 GXL with intake full true dual exhaust and the T2 drivetrain
thanks guys,
jeff

gear_grinder

iTrader: (4)

man, i dont even know were to get these thing can u tell me?

snowball

no, the megasquirt has its own case. you could reuse the old case i guess, but why?
heres the last one i built



DO NOT try to reuse the stock wires. they are nearly 20 years old and are falling apart even if they dont look like it. the megasquirt wiring harness is cheap.

any old POS should work 500mghz or better, you could try something slower though.

just buy the newest version, no reason to skimp on features.

puppyslaughter

ok sounds good so here is my next question which software should you use (i should prolly be asking this on the megasquirt forum but i dont really trust them like i trust you guys as far as rx-7's go)

GodSquadMandrake

Megasquirt is difficult and takes expert knowledge of electronics. If you don't know much about soldering or electronics you will after you do megasquirt.

My Jetta still isn't running and I have been working on it for over a year. I am not the best with electronics, but i'm getting there I guess.

GodSquadMandrake

You use Megatune to configure Megasquirt. Theres a whole package of applications you get when you download it from the Megasquirt site. It's basically all you need. Theres a thing called Mega Log Viewer so you can replay your engine on a graph and watch what happened etc.

Go on the Msefi.com forums. There are some rotary guys on there that have done this. I know for a fact there are some rotary specific things that make it more difficult. Read a lot first!

GodSquadMandrake

Don't forget to pick up an Innovate LC1 Wideband Oxygen sensor while your at it!



Their $200 at:
DIY Auto Tune

You need to tune Megasquirt with a wideband. If you get dyno tuning done they have a wideband so that'll save you $200 but the dyno's are usually like $90 an hour anyway. If you ever change anything you need to pay to have dyno tuning done AGAIN. So you might as well just buy the wideband and do it yourself.

puppyslaughter

thank you this was most informative

junito1

or wait and get a plug n play for the s4? heh

puppyslaughter

actually i dont really think i would enjoy that at all half the fun for me would be building it which brings me to another question how do i go about wiring the stock ecu plugs to the mega squirt

puppyslaughter

ok so disregard the last post cause i think there is a wiring harness that does that for me

West-se

If your going to get started right away get the Megasquirt I ver 3.0 but if you're planning to do this down the road get the megasquirt II since the extra code should be completed soon with all the rotary support. You can do your wiring yourself its fairly easy. Or you can buy a pre-made generic harness from DIY but its not necessary in my opinion. As for laptop anything capabale of running windows 98 or ME should do the trick. There is no different version of code that is better for rx7's and what mods you may have, its all in the tuning. Although not totally necessary a wideband is very usefull if you plan on tuning yourself, i'd say almost a must.

muythaibxr

I have to disagree... while code will be available for ms2 to support rotary soon, I will not have time to document it for a very long time, and megatune support for ms2/extra has some problems right now.

I'd suggest getting a v3 board with an ms1 chip, and then later on down the road when ms2/extra gets rotary support AND is stable, you can upgrade.

fstrnyou

FYI, i have an old 266mHz laptop with XP on it. although starting up and loading programs takes a while, it has no problems running MT or datalogging.