Megasquirt

And now, for something completely different.....

While perhaps not as much an interest item here, I am looking at learning as much about the aftermarket Megasquirt FI ecu as I can in as far as fuel control. The goal being to simply upgrade an older Bosch FI unit as simply as possible.

Interestingly, the Megasquirt can operate closed loop with an O2 sensor in the exhaust in what is a pressure-volume system ( like D jetronic) with inputs being MAP, air temp, engine temp, throttle position and rpm sensors.

While I am on other boards including the Megasquirt board, just wondering if any experience or advice out there?

Tnx

 

Depending on what year you are talking about, the megasquirt is far inferior to a Bosch.

For aftermarket stand alone, I am looking at AEM. I have a Motec and it makes my brain hurt, so I have to hire a guy and that makes my wallet hurt.

 

Don't forget TPS!

My trackday project car is on a megasquirt 1 v2.2 - if you have any questions, feel free to PM me and I'll help as much as I can. I wouldn't be able to give you any Ferrari specific MS info, but speaking in general, having ripped out the stock harness out of my car and rebuilt an entirely new intake and injection for a car that was CIS previously, it's quite an adventure. I can tell you though from going to something like CIS to megasquirt was amazing in the response and smoothed out feel. Still trying to get my VE tables right, it's been an adventure for sure. But a fun one! The first time on your first project is the hardest. After that, you'll have beat your brains in with reading the megamanual enough that you'll have no issues next time around.

Megasquirt can be as elaborate or as simple as you want it to be.

If this is going to be an ITB car, your largest obstacles will be making sure the MAP readings are correct (ITBs if not properly setup or not properly sealed will have a high Kpa reading) and really benefit from TPS instead of MAP. You'll also get a lot better resolution with TPS and the tuning is SO much better that way.

Also, it is about 100x easier if you tune the fuel first, leave your stock ignition system alone and then once you get the fuel dialed in, to worry about spark if you plan on going spark and squirt. Doing my ignition was a COMPLETE pain. Getting the fuel setup working was a sinch.

- You'll want a good trigger point
- Need to know how much of your current car's system you want to use (if applicable)

I could type all day about megasquirt.

Knowing HOW you want to do it will have a lot to do with which ECU you want to go with. I had to do a lot of wiring I had not at all planned on doing to get my MS 1 ECU to work with my setup. A MS 2 unit had a lot better options. It will help you a lot if you are familiar with understanding circuits and microcontrollers, because there is the possibility of having to open up the megasquirt and making a circuit, be it on another breadboard or protoboard, or maybe just running wires and jumpers.

If you are ONLY doing fuel, that may not be the case. It's a different story with ignition.

The beautiful thing I love about my MS setup is that I can datalog everything I'm doing, tune it on a whim at any time even on the fly, burn settings instantly, and the ability to upgrade and tune things is amazing. I cannot, however, comment on jm3's comments on the bosch unit again as I have no experience with it.

Couldn't help but respond though since we're talking megasquirt

Also, you won't need any Ferrari specific fuel items to design a fuel system. You need to simply know what your desired AFR is going to be, how to get the injectors to work for your car, what your fuel pressure needs to be, the fuel lines to run to your rail setup, and a pump that is appropriate for the megasquirt unit. I actually ended up using a Honda fuel system for my car, it fit right in the head on my car. As odd as it sounds, I ended up using GSXR 1000 throttle bodies, honda fuel system, carbon fiber intake runners and part of the stock ignition system with a different trigger off an HEI system to do my car. Overkill for such a slow little car. But I wanted to do it, so I did.

Reading material:

(brief overview on how a system looks)
http://www.megamanual.com/v22manual/mintro.htm

(Various wiring configurations and what you'll be looking at)
http://www.megamanual.com/v22manual/mwire.htm

(area for fuel injectors, including pounds per hour and even a calculator to help you superduperuberguestimate your required fuel)
http://www.megamanual.com/v22manual/minj.htm
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Can't help at all, but good luck Russ. I know you'll get it figured out.

Henry

 

Corse,

Would that motor just happen to be a 924?


Ago

 

I have expeirence with Mega Squirt. Great system and not a ton of money. Most can be purchased from ebay and if you need help setting it up.....Loads of help on the internet. Decide on which system is right for you and then price the pieces. If you need a list of suppliers, PM me and I will glady send you some.

Start here.......http://www.msextra.com/
http://www.megasquirt.info/

 

Yep, it's the same one listed in my profile. I considered it being my daily and using the 911 for racing. But for some odd reason, it seemed more fun to do it with the 924 since it was an odd one off.

Megasquirt can work on any car though, with time, patience, planning. As Turbopanzer mentioned as well, it's not terribly expensive either.

 

Actually it works better than a lot of the hi-dollar units. It can work on just about any engine and when using the Bowling-Grippo software, it is pretty easy to setup and get the VE correct. On a dyno, you can go thru it like Grant went thru Richmond. I pefer over AEM or any of the Bosch stuff. Best part is all the sensors and stuff are straight of the shell Gm stuff. A full setup for an engine I did ran about 400 bucks. And the thing is bulletproof.

 

That was a huge reason I wanted to go that route. I plan on doing some endurance races with the car at PIR and ORP. With my CIS system, it was becoming a NIGHTMARE to try and get the thing to run reliably. The last thing I wanted was to end up broke down at the track. Now I have a reliable fuel system, wiring setup, parts and if anything breaks, it's a simple trip to any parts store to replace something instead of waiting on expensive and hard to get parts.

I love microcontrollers too, and though I've only been tinkering with microcontrollers for a little under a year, I have to say it's been a TON of fun to learn. Thanks for not shunning me for modding a 924 LOL.

 

Are you kidding? Shun you for that? Hardly...Wanna hear the kicker? I am considering if my TR doesn't perform correctly with its CIS system, guess what will be getting a brand intake system featuring the entire MegaSquirt PNP system? The thing is cheap, bulletproof and a heck of a lot of fun to tune once you get the hang of it. I have a flowbench in my basement machine shop and I have been playing with some ideas and the MS3 & MS3 can do a lot more than the current setup including upping the fuel mileage. We shall see, but stay tuned!

 

I'm liking this forum more and more every time I read and post here. I've got some hate on my project a few times just because it's a 924. I think it's cool that we've got some really open minded car enthusiasts here.

Also, I'm jealous that you have a flow bench!

 

They are a great thing to have. You can actually setup your fuel sytem on the flowbench. I have done several engines where all you have to do to make the fuel system pefect across the board was simply raise the fuel prssure a few pounds. You are doing the right thing going MS because a lot of the Bosch CIS stuff has been discontinued. I am a total fan of your 924 getting "squirted".

P.S. A 924 is a real good car when you get them setup right.

 

Let you in on a little secret .....If you want you can change Megasquirt to MAF also. Fast easy and you can run one throttle body!!!

 

Corse,

25 or more years ago, I converted a friends 78 924 to dual side draft Weber carbs, reground hotter camshaft, raised the compression by decking the block and retiming the camshaft. It really woke up that car. would do over 130mph.



ago

 

Thanks everyone - great discussion. The car currently has D-Jetronic, and I wanted to keep the outward appearance but perhaps add some tweaking using the wideband feedback. The MS-1 seems almost custom tailored to upgrade D-Jet, allowing for a more modern TPS to be adapted.

Again, many thanks and all advice welcome.

 

Do you have any pictures of the current setup and sort of where you want to go with it engine bay wise?

Keep in mind that what kind of TPS will be irrelevant as long as it's a basic unit that just uses a ground, 5v input, and a signal wire, that's literally all there is to it. All the megasquirt cares about is a range. So you can calibrate it so long as it's capable of registering the 5v connection coming from the megasquirt. Think open minded when it comes to the sensors and setups. The reason I went with the ITBs I went with is because it already had the TPS and vacuum setup ready to go for being able to hook up vacuum and everything else I needed.

Likewise, one can easily adapt something onto throttles they already have too.

Also HIGHLY recommend going with a copy of tuner studio for tuning if you go with megasquirt. I tried going with the normal megasquirt software and hated it. I tried tuner studio and found it to be easy to learn, intuitive in placement, easy to customize gauges and excellent to use overall.

Nice things you can also monitor even on a megasquirt 1 unit:

- TPS position and calibration (literally as easy as taking foot off throttle, hit a button, then pushing pedal, hit a button, and your TPS is calibrated.)
- TPS fuel per second - you can tell it how much fuel you want to send when it sees the TPS move. For instance, you could tell it that if you see x per second movement on the tps, it will send x fuel. You can also go into diagnostics and you can see if it's reacting properly as well.
- Tooth/Trigger logging - really important so you can see if your trigger pickup is consistent or not, or if you're missing a tooth, etc.
- O2 Input, you can see where the O2 bank is reading and how much correction is taking place
- Intake temp, coolant temp
- You can also datalog AFR (air fuel ratio) in real time and also if you want to get really spiffy, you can even whip out real time VE (fuel map) and spark mapping as well (if you really end up wanting it to control spark as well)
- Spark advance and trigger angle control (also entirely optional if you want fuel only) but the nice thing is that you can adjust the trigger angle to be spot on and then you can control a fixed timing, or go off the table. Sounds like a pain, but it's actually very simple to set. On top of that, you can set it up for multiple coils or systems if you want. But that DOES require a lot of extra wiring in the megasquirt unit.

If you're interested, I could toss up a vid on youtube sometime this week and kind of go through some basics on how it works on my car (it's really pretty much the same on most all cars, the difference is really going to be how someone wants to set it up, and one can do various different things on a megasquirt, but the concept itself is similar on most all cars).

 

Here is the engine compartment. I would like for it to remain as stock appearance as possible. Ideally, the best would be to replace the Djet ECU and harness and keeping as many original sensors as possible (air temp, coolant temp, tps, MP, rpm) and add an O2 sensor for trimming for an MS1 ECU.
I did see where the MS folks will build you a plug-n-play if you have 10 people.

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Two of the guys in a shop where I worked for a time built a megasquirt for their cars. Its a cool concept, a fully programmable Fuel injection map. But as I see it there are two caveats.
First, you can't really appreciate how many variables there are until you try to cover them all. The factories spend thousands of man hours working out those maps. Who has that kind of time? Second, Bosch really knows how to make an automotive component. The life of automotive electronics is as hard as it gets. They have to work under all kinds of heat and humidity conditions. They're frozen in the winter and baked in the summer. They're shaken and battered and bashed around daily, and they frequently have to endure random voltage surges as the other demands on the electrical system are constantly changing. I've never met an aftermarket component that could stack up to the durability of the Bosch equipment.

 

A friend of mine, (young engineer) has built Mega- squirt for quite a few cars. He rallies his turbo VW bug, Pounds it to death, Holds up well. But He is the young generation and is very competent with computers and like. Tells me (old guy) nothing to it. Someday I will try Mega-squirt. He says some of the V8 bolt on FI is based on the Mega-squirt concept. They took the concept and made there own FI.


Ago

 

MS3 has come a long way since the first quad4 OEM based stuff we used to play with, with now plug-and-play boxes available, and even auto-tune programming!

 

Agree that at some point high priced unobtanium could go to the wayside in favor of modern tuneable reliability. Keeping the car pure helps keep the resale price up and one would have to consider the impact if selling at a later date. So just for gits and shiggles, I was wondering how the induction system (fuel pump, injectors, air valve, air flow measuring, computer, oxygen analyzer etc) from say a donor GM straight six like they put in the Trail Blazer would work on the 12 cylinder engine? You could use two systems one on each side of the engine. One GM system makes around 300hp on the 4.2 liters so two throttle air valves might be too much air flow into 5 liters. I suppose you could go to one properly sized throttle air valve. Food for thought. Thanks, Ray

 

Air flow into an engine is a matter of port configuration, airflow restrictions and engine exhaust flow. Even the BIG throttle will simply flatten out air flow at some point. The real issue is throttle response. A fast dump of air into an engine will create a different issue. The on-off throttle response will be more erratic as the fuel-air mix becomes unstable. Instead of positive air fuel density, you get globs that cause overly rich or overly lean conditions based upon engine demand. As for the GM parts, pretty much a straight forward changeover. Keep in mind one thing....any engine is only as good as its induction and exhaust systems. More air in with an exhaust that allows more air out means improved power across the board. The TR engine is derived from F1. The restrictions come from how the engine is housed at the rear of the car. Tight bends do restrict both the intake and exhaust airflow. Getting rid of the current intake system and replacing it with a tunnel ram type or induction plenum type system will yield more power, but you will lose engine flexibility. Individual runner system offers flexibility and improved throttle response, but limits top end airflow. You decide what you particular application is and then determine what you want to give up.

One other thing....Megasquirt is a system that can be tuned in many ranges. Even a factory manifold setup can be tweaked to yield power gains. It really becomes a matter of machining parts to fit correctly. The Bosch system can be modified to utilize M/S. You simply take your time and decide what you want to keep and what needs to go. Follow the formentioned links and read up on it. It has tremendous potential.

 

It was my understanding with port fuel injection that big throttle openings did not have the same over carburation results as a carburetor. You don't need velocity to pull the fuel up the spray bar as on a carburetor.


Ago