Over the course of the last few weeks of researching my project I've been looking at the MSII PnP to run the planned Millenia SC'd NA . I'm hoping that by including this thread might give enough of a background. I hope also that I might be able to find somebody here who can advise me as to what to do before I make a mistake fatal to my engine. Can someone point me in the right direction where I might find the info I need as a noob in the MS world to do this tune safely? Everything I read just seems to confuse me even more than when I first started.

I've been aprehensive though of blowing my engine because of my inexperience in the tuning department. I understand the PnP comes with a base map to allow the S4 NA to start and I'm going to have to go into uncharted territory, Or at least that's how I feel. I'm told that TII base maps would not work since boost will not come on at the same time for the the SC as compared to the turbos. Anyone know of an SC'd NA with some experience in this department? Or am I worried for nothing?

I intend to get an LC-1 for my wideband and from what I understand is that I can attach this to the MS and that it has a learn function. Will it "Learn" fast enough to counteract any detonation problems or would it be too late by then? I just read this thread https://www.rx7club.com/forum/showthread.php?t=529708 and it makes me have to wonder.

I understand that I can stage my secondaries earlier and retard ignition upon boost and start moving things around after but can the adjustments be made while it's running and logging simultaneously? I do like the idea of going MS but would also like to know if I could use the PnP and still be able to use the HEI transistor to raise ignition spark for leading and trailing.

Pardon my ignorance but there's just so much I have to find out and learn before I make the jump to MS. Right now I'd almost stick w/ the stock ecu if it weren't for the fact that I need to remove the AFR due to space constraints under the hood for my application.

Hope I can find some answers soon, Sure would have liked to been able to place an order on the first batch of PnP's had I been ready. Any suggestions to my project to SC the NA would also be appreciated.
Thanks

 

Something I might not have mentioned before also is that I might actually have a way of attaching the supercharger in such a way that I'd have a way to switch the SC on or off. I would like the capability to run NA and switch to blown and have the ECU switch modes to compensate for boost immediately. Is that possible? Would the MS have that capability?

Anyone? Muy, Renns, Tofuball? Anyone Please?

 

ErixHvn,

If you are new to EMS's, and tuning, then this is a high risk DIY project. Are you planning to do all the tuning yourself, or will that be farmed out to a local shop? If farming it out, then consider using the EMS that your chosen shop recommends, as they'll be doing the work. If you do plan to do all the work yourself, then I'd suggest you build your own unit, take your time, and read the documentation at msefi.com.

As for West-SE's issues, take a look at his more recent thread, that outlines the probable cause - mixed high and low impedance injectors.
https://www.rx7club.com/forum/showthread.php?t=533218

I know of no one running MS on a supercharged rotary, but I don't see any particular complications. Switching the SC on and off will cause potential issues, as the VE at the same load point will surely be different. I'd suggest switching on at a chosen rpm, and leaving that switching point fixed. After the install is debugged and running well, then you may want to look at the table switching option, which is already built in to MS, and try custom switching points. Check the capabilities of that SC clutch as well. Many do not like being switched on at high rpm.

 

I would personally just use a bypass valve instead of a clutch. It's much simpler and that means less to go wrong. I'd leave the bypass valve wired open until you learn how to tune the ecu properly without boost. I'd even go so far as to buy a few different pullies. Get a large one at first so you literally only have a pound or 2 of boost. Tune this area then switch to a slightly smaller pulley that will raise the boost a pound or two again and repeat the process. This will let you slowly get a good map. Also only tune small rpm ranges at a time. Start at idle and go up 1000 rpm or so at a time. Start out at low load levels and slowly increase it. This process may take a while but it is pretty safe and that is much faster than rebuilding the engine again. You'll also learn alot in the process. Definitely build it yourself. You'll never really learn it if you don't. Luckily a supercharger is an easy boost curve to tune to. It isn't like a turbo that suddeenly comes into boost over a very small rpm range. I wouldn't be scared. Just be careful and take your time. That's the hardest thing for people to do.

 

you can run the dual table code so whenever you switch the SC on or off, it switches tables as well. I've never wired such a thing up though, so I'd have to go find out how.

 

Thanks Gentlemen.

For all your suggestions and comments. Rotarygod, You've been there almost from the start. Owe you big time. I figure by the the time I'm actually done with this project I'd owe quite a few people for their contribution of their knowledge.

Muy, Renns, I didn't even know MS had dual tables. YAAAAY. Then there is a possibility I could get it to work with an RPM switch to turn on the SC and also have manual switching. Question though, which version MS is the PnP? Does it have this feature? And as far as educating myself to the tuning portion of the MS where should I start reading as an MS noob? Could you direct me to the right place to start where there's some progression so it's not so overwhelming.

Renns, As for your concerns about the clutch, I'm going to try to find a dual pulley AC compressor clutch that fits the SC shaft. Only to retain the stock pulley setup of the S4 because I intend to mount the SC the somewhere near where the air pump used to be. Switching will be done at low rpm's (ala M Benz SLK)or at idle/cruise not WOT. I'm also wondering how the clutch would hold up. But at this point I'm more worried about blowing the engine than anything else.

Please keep the suggestions coming. There are days that I've wanted to give up but for guys like you showing interest in this project of mine.
Thanks!

 

The PnP is something that me, tofuball, pele, and a couple others build. It doesn't have the circuitry necessary to do the table switching, but it wouldn't be that hard to add I don't think.

As an MS n00b, www.msefi.com, and www.megasquirt.info are good starting points.

 

I've been looking in the wrong places all this time. Thanks Muy. Dont know how I missed those links. Musta been too dazed to see it as they're all over the other threads.
So can I order the PnP configured the way I need it? Not the electronic whiz at all even though I actually ran a RadioShack in the 80's. Besides, My hands aren't as steady as they used to be. Soldering would literally be a pain. (Carpal tunnel syndrome).
Got a lot of reading to do ahead of me so I better get to it.
Thanks Again

 

you'll have to talk to tofuball about that. Just PM him a message and tell him I told you to. I'd like to keep discussion about that out of the public forum as much as possible.

 

I don't have an MS yet but I have been on the MS forum for a few years and I also have long experience with an MR2SC.

Whether or not you have a clutch you still should have a bypass valve. The open bypass valve should not have a big impact on your VE (probably noticeable but not huge) so you can probably use the turbo fuel and ignition maps out of the box. The turbo fuel maps may not be accurate for boost at low RPM because a turbo doesn't work there but it shouldn't be too far off. You should probably retard the timing for low RPM boost too. You should be able to work fine without dual tables.

Your boost should be comfortably controlled by the throttle (no sudden surges common with a turbo) so you should be safe as long as you can restrain your right foot. Slowly work your way up to full boost over the course of weeks. You can modify the spark and fuel maps for extra fuel and less advance on overboost working your way up slowly.

But definately wire the bypass valve open for the beginning.

Clutch switching can be done like toyota did it. First the clutch is engaged while the bypass is still open at a few inches of vacuum. At that time there is no real load on the clutch. Then as vacuum gets closer to 0 the bypass valve is closed and boost starts. You could make some modifications to MS to controll that but it is pretty stupid so some simple hobbs switches could do it without any help from MS.

As I understand it, learning mode can help refine the fuel map but I don't think it can save you from sudden mistakes. You will have to rely on slow and careful progress.

I would guess that your biggest danger would come when you have your fuel and ignition maps mostly complete and it's time to fine tune for transient acceleration.