autopaul

will this need a crank angle sensor?,
i was wondering how this will all go together, or if its better just to use the stock ignition, with a msd, or something,
i was also wondering if anyone has any costom intake setups with 12a megasquirt or other fuel injection, i wanna see, any ideas, what throttle body to use, what high impedence injectors to use, so many q's about convertion to FI
any info you can give will be greatly apreciated

rotarygod

iTrader: (1)

I just built a megasquirt for my streetported 13B. I am using a stock distributer. It works good running in MSD direct fire mode so I have no need to replace it. It's better to learn how to tune fuel only for simplicity reasons. Later on you can get into ignition. You don't want to get overwhelmed buy learning too many things at once. Megasquirt can be made to run the ignition on a rotary with some board mods. You have only 2 options as of this time though on how to do it. You can use the Ford EDIS system which you'll have to source pieces together for. The different options come into play with how you actually fire the plugs. You can either run only the leading plugs and use wasted spark mode (or not) or you can not use wasted spark and fire the leading and trailing plugs together with no timing split. As of this time, Megasquirt does not have the ability to control leading and trailling timing independently.

You're oprions are limitless on what to do in terms of manifolding, injectors, throttlebody, etc. Get creative here. You'll get tons of different recommendations and all of them would probably work just fine. One thing you will have to do is get a higher pressure fuel pump and regulator and do the necessary fuel system work.

johnnyA101

I have started looking into install MSII into my car as well. Although I think it may be wise to get the car running on its own first before starting any type of fuel system conversion. According to the information I have found so far, no. Well maybe. It seems that all of the MegaSquirt installs so far have been with the original version and even at that a few different methods have been used. At this point I am planning to running the stock ignition. I would start with the info from the link below if you haven't already done so. As far as intake my initial thought was to start with a manifold for a dual carb setup like the one used with a Weber DCOE or IDA carbs (I am leaning towards the DCOE manifold). As far as the actual throttle body I am not so sure. It is most likely going to be using a GM setup, they used a fairly similar design on several different engines. One type was on 4 cyl and smaller V6's and another on larger V6's and V8 engines and just altering the flow rate of the injectors accordingly. Basically I am looking to do a TBI style rather than a port fuel injected setup. Either way it is going to take some creativity to do it. I do not know what injectors would be the best at the moment, I know just as much as you do.

John


http://www.megasquirt.info/manual/rotary.htm

rotarygod

iTrader: (1)

If you are just using a non forced induction 12A or 13B, find a set of 4 injectors from a 2nd gen. This would be easiest. I'd recommend the Holley intake manifold from Racing Beat. It is $204 for a 12A or $228 for a 13B style. Get a Holley style throttlebody. This is where the savings come in if you know where to look. Typically a new manifold and tb combination will set you back many hundreds of dollars. I've found a Holley tb with injector holes for only $75 new!!! That's $300 for an entirely new manifold setup that can't be beat. FWIW: There is no other manifold out there on the market that outflows the RB Holley manifold. You can't lose with this system. Check out this website for the tb:

http://www.auto-nomics.com/cgi-bin/s...rt=10850-002-D

Buy a standard Megasquirt first and learn how to use it. Since MSII is still being Beta tested, you've got plenty of time to add it later. It will be as easy as removing the stock chip and installing the daughter board in it's place on the standard MS. If you want ignition control, you'll have to change a couple of things.

numan2

that throttle body link was just what I was looking for! I want to try running a megasquirt on my 12A but cringed at the thought of buying a used holley TB for over $500.

QuagmireMan

switching to FI is ideal but it is just too expensive. Why not buy a 13b and drop it in? You might be able to pull it off for alittle more and i bet you would have alot less head aches.

numan2

I don't always take the easy path that's why I choose rotaries and I like to build my own stuff for my car so the megasquirt is right up my alley besides if I don't like it for my RX I'll put it on one of my other projects.

Jeff20B

iTrader: (13)

I hadn't touched my MS for a couple months due to being too busy with other projects, but I soldered a different bias resistor to R4, because I'm using stock Mazda temp sensors, and cleaned the flux off the PCB and installed the case the other evening. The next step is to build a harness for the sensors.

As for ignition control, I'm not interested in Ford EDIS because it lacks the dual leading sparks that DLIDFIS/MSD direct fire has. Well guess what: one of the braniacs working on some new code mods has written a wheel decoder that should be compatible with a CAS. It will even allow dual leading sparks. What I'm really exited about is that it will also allow dual leading sparks at the correct times on a 20B.

Like rotarygod said, it's best to start with MS controlling fuel only and learn all about tuning etc before getting into ignition. It's what I'm doing on my MS 20B project (modded 12A dizzy for dual leading sparks on a 20B).

Edit: all this is based on the classic MegaSquirt. I don't know very much about the MS II. I think it's going to have a different CPU that can take higher temperatures which means mounting in the engine bay is possible.

rotarygod

iTrader: (1)

MSII is kind of an intermediary step between the original MS and MS-Ultra. It just takes the standard chip and replaces it with a plug in daughter board. It's a 5 minute mod. If you have a standard MS, upgrading it is simple.

nimrodTT

I did some checking on this throttle body because it looks like a really good deal. Unfortunately I found some stuff that explains why it's so cheap. First off it's made as a replacement for a throttleboy for a company called Airsensors. The way this company did EFI was without the use of a TPS, and the TB does not come with an IAC. If you want to use MS, you'll need the TPS added - which is machine work to the body and an extension added to the throttle shaft (I'll assume without some sort of seal to prevent a boost leak). So the guy says he'll add the TPS for you for only $65, and he has a GM IAC for $60 on the website that apparently screws right into place. That brings you up to $200 even for the TB alone, and over $400 with the manifold, which still isn't too bad. But then there is the problem of no fuel rails, mounts, mounting provisions for any type of rails, no gaskets, no individual vacuum ports, etc. I also happened to ask if the flange is a holley copy, he didn't answer, but it does look very much like one.

Just something to consider before anyone buys this setup.

numan2

well I'm not opposed to doing some mile machinework to the throttleshaft or the body to add a TPS to it so that's not too bad and while doing that sealing the throttle shafts for blowthrough wouldn't be too bad to do. It looks like there's a boss between the injector holes to mount the rails and injectors to it. Adding vacuum ports isn't a real issue either but it appears from the picture there's atleast 1 port for each throttle blade and 2 larger ports on the rear so there should be plenty of ports. The flange looks like it will bolt to either holley, carter/edelbrock or q-jet manifolds too.
All in all I think I might just have to get one to play with it's either that or start hunting down a decent holley to work with and I'd prefer to go EFI if I could.

nimrodTT

I mis-spoke about the vacuum ports, you are right. There looks to be an allen key between the injector ports that you may be able to use, but you really want more than one mount point per rail - you could easily come up with sone bent flat stock aluminum that attached to the mounting ears on the TB, but the point is that the thing doesn't come with pre-determined provisions for rail mounting. The reason behind this was that the Airsensors setup used injectors that had barbs on the ends so they could be hose mounted as seen below.

He seemed like a very helpful guy and was nice enough to reply to my email on christmas eve. I may pick one up if I'm still stalling on the manifold for my other throttlebody setup as this one is much less work - but a little more work than I was hoping for. Here are the pics he sent.

numan2

unless your doing blowthrough the injectors should stay in on their own if your doing blowthrough then the injectors should only see a max of 15 pounds pressure seeing as their diamater at the tip is less than 1/2 in. and that's not alot to hold in

siragan

iTrader: (1)

Maybe you'll find this interesting:
taken from: http://www.race-cars.com/carsales/ot...54757039ss.htm



I'm in exactly the same situation. I'll probably build my own intake runners/injector bungs. I don't know if I'll build it from scratch, or if I will use a butterfly'd dual-runner intake adapted from another car. That's still up in the air. It'll probably use the TB/IAC/BAV unit from another car, and then the injectors will be placed near the ports.

bill Shurvinton

Hiya. I'm the 'braniac' working on the lead/trail split for rotaries with MS. hoping to find some time over the next 2-3 months to get some code in place to start testing with the mazda CAS.

Coupla things to note for people.

1. You don't actually need a TPS for MS. Mike Roberts developed some code changes to use MAPdot instead of TPSdot for acceleration enrichment.

2. Having seen the racing beat dyno graphs for their holley setup vs their weber manifold on EFI, the weber creams the holley all through the rev range.

However that 4-bbl TB is a real steal. may score a couple of those just in case.

Jeff20B

iTrader: (13)

Will your code also support dual leading sparks? Or should I call it late leading? Or should I call it simultaneous firing? Or should I call it the piston engine term wasted spark? And will it also support three or four ignition output channels?

jsmcortina started working on a 12-1 wheel decoder recently which can work with a Mazda CAS if two of the teeth are removed from the 24 tooth wheel and the other VR sensor, for the upper two tooth wheel, is not used. He said that in order to use both VR sensors inside the CAS, a keyboard input would have to be sacrificed, which requires a bit of rewiring of the CPU, or something. Sorry I can't be any more clear, but it's been a couple months since he and I exchanged PMs on the subject.

All I want is a code that can handle three ignition channels at the proper times according to my requirements (available upon request). Oh, and staged injection of course (already handled with renns' code mod). I wouldn't even mind if all three LED circuits on the PCB were converted to trigger GM HEI ignitor modules or what have you. I have no need for dwell control in the code or any of those extra features like water injection, launch control, or even fan control... well, fan control would be nice, but not a necessity. Too bad I suck at assembler.

bill Shurvinton

Complete specs have yet to be finalised. All the notes I have from when I was looking at doing the code for MS initially was based on the stock factory coil packs. No reason why I couldn't change that to 3 ignition channels though in a future release. However in your case you have such orthogonal views to everyone else on how the leading spark should be fired that I doubt the first few releases will meet your requirements unless it drops out automatically.

I do need to talk to James again to try and see where we can share resources on the 2 code bases so we don't end up repeating work.

FWIW there is a 4 rotor drag engine here in the UK that is running very nicely with an EDIS-8 and Renns has a lot of miles on an EDIS-4 in his car, so the EDIS solution does seem to work if you are not overly concerned about ignition.

Jeff20B

iTrader: (13)

It's only because I've tried it both ways and prefer that extra leading spark at 180° on all my rotaries. I won't own/drive a rotary without it anymore. It's true that if I didn't know or care about it, I'd probably go with EDIS-6 right now on my engine because the code loaded on my MS supports it, but I can't in good conscience, knowing what I know. EDIS-6 basically would provide less sparks to the mixture than my current direct fire dizzy mod does, even with trailing (sparking through the tiny trailing holes in the rotor housings). There is also no split with EDIS, and I'm not a great fan of the resulting exhaust note because it sounds more like a V6 than a 20B.

Oh, and renns' buddy did some dyno testing on a stock FB (through the cap) ignition system on a 12A with MS and tried it with trailing on and off. The difference was around 1.5HP or so. I figure the higher energy available with a direct fire leading ignition system as well as that late leading spark, which I'm so fond of(hehe), makes up for the loss of trailing, and then some. Anyway, that's the logic that I used when deciding to run leading-only on my engine, plus I could not justify the use of three more ignitors and coils to provide such little return when they'd be put to better use on some of my other two rotor engines around here.

Test firing the engine proved interesting. Even with a crappy makeshift carb setup that would go rich at the drop of a hat, and static timed as accurately as I could muster (given the circumstances), it reved quicker than the Pac Performance RX-3 but wouldn't idle. Not too shabby. I'm happy.

Yeah, get in touch with James. He's flying through the code mods right now and even impressed Mr Grippo.

I think one of the things holding a lot of RX-7 owners away from MS is that it doesn't have support of the stock CAS, unlike so many other commercial ECUs out there. Perhaps your code, or James' could finally unlock the doors. I've got a CAS just sitting here collecting dust.

By the way, does that four rotor drag car have an ignition event every 90° (so it sounds cool), or every 180° (so it sounds like just another two rotor)?

bill Shurvinton

Ah confusion. I was referring to your 3 sparks per event theories. Stock type spark at beginning and end of combustion will be supported.


The real problem with the MS1 is that the processor memory is completely used up. James has done some clever stuff to page tables in and out as needed to make the most of the design, but some considerable rework will be needed to handle a CAS. MS2 has 6 times the processing power and 8 times the memory, so the task is much easier on the new platform.