plug 'n play MS prototype finished
 

The plug 'n play MS for S4 2nd gen rx7's is done and works. I started up my 86 S4 GXL on it today, and it ran great!

Here are some pics of the unit itself:


http://www.speakeasy.org/~culverk/plugnplay1.jpg

http://www.speakeasy.org/~culverk/plugnplay2.jpg

http://www.speakeasy.org/~culverk/plugnplay4.jpg

I'll post vids of running and tuning as soon as I get the stock wiring harness's grounds fixed and get the stock harness's coolant temperature sensor connector fixed (I had some grounds rigged up and jiggled the harness until the coolant sensor worked... but this isn't because of anything wrong with the MS, this is the fault of the factory harness in the car).

I saw it! It's fantastic! :D

wow.. thats nice.. i really want to see a vid.. im wanna try my ms on the vert.. but im affraid i might not want to remove it . haha..

That looks great.Do you have to shield the ignition VR sensor leads,or is it not important on a short run? Are these 2 leads twisted together for a reason? cheers

inside the car, and for such a short run, the shielding doesn't matter so much.

The ones that are twisted together are just not wired to anything yet... they are the fuel-pump relay wire (which isn't used on an S4 if you leave the AFM in.... if you take it out you can use that wire to trip a relay to turn on the fuel pump) and the O2 sensor wire, which I haven't hooked to anything yet b/c I'm going to be tuning the GXL to get base-maps using a wideband.

Pricepoint? Availability? If and when? Thanks. Keep up the great work!

Price: depends on how hard it is to get the ECU plugs. Most likely between $400 and $500

Availability: depends on how hard it is to get the ECU plugs, other than that, as soon as pele, tofuball, and I can build up a stock...

I also want to put together some good base maps so people can fire their cars right up as soon as they plug in.

Depending on time and money (it's a bit expensive to buy a lot of kits at once), I should be able to have several within the next month... and also depending on time, I should be able to have a wideband-tuned base map.

Nice work Muy. I have 2, S4 ecu's N326 style that work but as we all know are not worth much. Id be happy to trade them both for a in dash cd player used is fine. Thanks for the great work and let me know if your interested in the ECU's.

haha, I'd rather give you money, I don't have an in-dash CD player that I can give you.

I have a N326 paperweight sitting here. Want it? I think everyone who has benifited from your work and shared info owes you one. haha

I'll take it.

i found that the 80's toyota ecu uses a very similar connector. two of rx7 harness connectors will plug in. i built a adapter harness pretty similar. i wish i made the harness somewhat longer so i could get megasquirt off the floor. it rains alot here and my car leaks.

I am planning on doing the same but for a S5 TII.The S5 uses a two-stage voltage output for the fuel pump,what would be the best way to tackle that? cheers

Ken,

That looks great! I'm sure there'll be a good market for these. Have you found a source for the harness connectors yet? Finding and scrapping old ecu's seems like a hassle for production quantities.

Griffin,

Here's one option: Power the pump with a series resistor like stock (S4's?). Use an auxilliary output to close a set of relay contacts that bypass the resistor. When the auxilliary output is on, you have full pump voltage. When off, you have low voltage.

Either replace the stock FPR with one that can handle the full fuel pump flow or wire up a MS output to activate the fuel pump relay resistor. Just make sure that if the circuit fails, the fuel pump will run at full voltage.

Yea man send me a few bux for USPS and ill send you a GSLSE ECU if you like.
aaron
email

I have a stock second gen convertable in dash CD player I will send you for the two ECUs. :)

we have tofuball's set up to run full voltage all the time... and it seems to work fine.

Not yet, pele is working on getting AMP to custom make us some if possible. Until then we're using scrapped ECUs.

Ken

Tofu,
Thats nice but I need a aftermarket cd player for a DIN sized opening with RCA outputs. CD players are cheap now. If you and Muy want these ECU's thier the N326 style 2 of them just let me know 30.00 each . I paid more than that but dont think thier worth more especially for your purpose. I also have a GSL-SE ECU but think they use different AMP plugs. If you want me to remove the plugs to save on shipping thats not a problem. I am in NY so shipping to MD would be fast and reasonable. You can email me directly if wanted at Azenis29@aol.com thanks for the input.

Nah.

Thanks though :)

So when is the S5 version coming out? ;)

I fairly intrested in picking up a plug'n'play for my S5. I need to talk to my father because he is the electrical guru when it comes to stuff like this. If he isn't intrested in building one with me then I will definitely be in the market for one.

I also have a S4 ECU you guys can have if you pay shipping. ;) If that will help you guys out any (Especially if that will make the S5 version come out faster ;)). PM me if intrested.

I'll do something about an S5 version as soon as I get 2 things:

1) an S5 rx7 to test on
2) a spare, busted S5 ECU to steal the connector from. I had one somewhere, but I can't seem to find it now.

I or tofuball will PM you about the S4 ecu.

Ken I've got an S4 and an S5 ecu you can have.

Sounds good. I would gladly let you guys play with my S5 if we lived closer. I'm planning on picking up a DD soon and would gladly let you guys play with my car as long as it takes but, I live in Oklahoma. :(

Someone with an S5 in MD.... STEP UP! Help these fine people out!

On the subject about the ECUs I will go raid the local junkyards and look for some too. You can of course have those for free or for around free depending on what I have to pay for them. ;) Prolly not too much. Heck, maybe even for free if I get a good discount when the S5 version comes out. ;)

Cool, tofuball's car is an S5, but we rebuilt the harness on that, so it's no longer anything like stock.

There's another guy here with an S5 turbo, but he is also rebuilding his harness (noticing a pattern here?) Even my S4 has ground problems, I fixed the power grounds, but I have still got to fix the signal grounds... right now it runs like crap on the stock ECU (although it runs great on the megasquirt). The point is that the stock harnesses on these cars are crap.

Anyway, if someone around College Park, MD doesn't mind me using his/her running S5 as a test mule, that'd be much appreciated.

so when do you forsee a working plug n' play model with a base map or 2 ready to buy? (s4 tII)

We won't have a TII base map for a while (tofuball's TII isn't registered yet), but we'll have plug 'n play units ready in 2-4 weeks assuming we are able to get more stock connectors.

MTB, do you have some way to come up with a good timing map for a TII? I was thinking of looking over the maps from the other ecu units and seeing if I could come up with a descent, safe map.

Is there any way you could run a stock ECU on the bench and measure the timing outputs? I know how to do it but just don't have the equipment.

I'm coming to the conclusion that the tuning of ignition could be a serious show stopper for my use of MS for timing. On NA engines it's not as big a deal, but modded turbo engines that see 10-14 psi can easily be blown by bad timing. I have EGT logging so that helps but really it's only part of the equation. Another needed input is knock sensor--perhaps use the stock knock sensor and run it into the MS...?

I feel like the stock map may not be the most optimum, but it should be pretty safe to run up to 10-14 psi with some additional retard after 9 psi (like RTEK). My current setup with Rtek 1.7, solid fuel system, and FMIC has been trouble free. I think the other saving grace for my setup is the lower compression S4 TII rotors.

Right now I'm kinda on hold with MS deciding what to do about the transition hesitation and ignition timing--once these two things are resolved I see no problems ahead.

Scott

I solved my transition problem by moving the transition point higher in revs about 300-400 rpms higher than when the aux ports open. For you just pushing the point up the revs may do... I may also look into having up to 2 configurable transition points... one for revs and one for MAP or something like that... so you can box in a point on your map where it's primaries only, but when you get on boost or when you go over a certain rev point, it'll bring in the secondaries.

I'll have to look into that feature I was talking about... I don't know if I'll have time soon, but msns-extra is always a work in progress, so I'll work on it as soon as I can.

As far as generating an ignition map, I was just going to use the stock NA map, and gradually increase the boost, while lowering the ignition timing enough to be safe.

I saw a post on msefi at one point or another that described a method for determining good ignition timing on boost:

From this thread:

http://www.msefi.com/viewtopic.php?t=9941

"Finally, for boosted engines, you subtract 0.3° of advance for every kPa above 100 (it's not a coincidence that this is the same factor as for the 'vacuum' adjustments). Because 101.3kPa=~14.7psi, this works out to ~2° per pound of boost. It is often the case that you want to limit the retard under boost as well, typically so that it takes out no more than about ½ of the maximum advance at 100 kPa"

I'll probably take another degree out or so from what they say to do here... just to be absolutely safe.

As for the knock sensor... the circuit for that is rather elaborate... and I don't have the parts to create that circuit right now... although I can definitely see the benefit of having it, I'd almost think that by the time the knock sensor hears knock, it's already too late, at least on a rotary engine.

Between 400-500 is a good price for that system. I would seriously consider that if they go for this price without a doubt.

do will still need to chunk the stock airflow meter? or is there a sensor we need thats house in that bastard?

Ken,
We have a brave blue 91 S5 NA coupe at the shop but it does not belong to me att. I will check with the powers that be and see about getting it over to you guys.

Cool, that would be helpful if it's still in running condition

The only thing the S4 needs the stock AFM for is to turn on the fuel pump... You can rewire it (I leave a spare wire free on the plug 'n play harness) so that you don't need the AFM anymore and let the MS turn it on, but then it's not really plug 'n play.

if you still use the stock harness on the s4, i just use a jumper wire on the fuel pump check connector,near the right shock tower. i checked the wiring schematic and the check connector is in parralel with the air flow meter fuel pump switch. thats how my car is set up.

I am so incredibly interested in this be sure to hit me up when you guys get some in production to sell... thanks

That's a little dangerous--you need to let MS control the fuel pump. If you jumper the check connector, the fuel pump will run anytime the ignition is on--even if the car is not running. It's a safety issue, you could get in a wreck and end up spewing fuel all over the place while you're knocked out or trapped.

The right way to do it is to have the MS replace the AFM circuit, thus MS pin 37 provides the ground on the circuit opening relay to turn on your fuel pump. You should have no problem doing this.

If you need help on the wiring diagram, just tell us what kind of wiring system you are running.

Good luck,

Scott

oops! read next post, muythaibxr.

MS prototype finished...
 

I just want to make sure I understand this: it IS possible to ditch the AFM by using an MS box? Does the same apply for MSII, which is what I'm currently assembling? That would be cool... Please elaborate.
Thanx.

-turb'd

an ms2 won't control rotary ignition... but yeah you can eliminate the AFM as long as you wire the MS correctly to turn the fuel pump on and off.

Just wondering if you knew that the ms2 won't be able to control the stock 2nd gen ignition system (can't read CAS, and can't fire trailing).

Yeah, I know about the ign. issue in the MSII. I got it for the upgrades/expandability - will be used on future projects (non-rotary). I'll just wait patiently until the code for rotary ign. is done. I have other beasts to build that'll satisfy my appetite for boost w/o an ECU! In the meantime, I'll just run the stock ECU for ign. on this car.

Just curious, is the method for wiring for this mod that Rex4life stated, the same for both ECU's or are there differences?

T.I.A.

-turb'd

it's the same... you just wire the fuel pump relay output to the MS to the coil pin on the relay, specifically the coil's ground pin.... One way to do this is to just run a wire from the MS to the pin on the check connector that goes to the relay.... that should give the MS control of the fuel pump.

This is really the only part of my setup (aside from the vacuum line) that isn't plug 'n play, and there's really no way around that on the S4 as far as I can tell... I think there's a way around it on the S5 however.

Hey muythaibxr,
I appreciate the feedback. I know you could easily get burned out being a hub of knowledge for so many. Much respect.

-turb'd

wiring the ms to the fuel check connector is a good idea. but im old school, im use to just turning on the ignition to power my fuel pump. in my first gen i had a inertia kill switch, never had to use it which is a good thing.

Hey no problem. On the days I'm slow to answer, just consider those "burn-out prevention"

Or in some cases, "I'm too busy working on soldering/coding/testing in my car to answer questions" :p:

Muy, any ideas when you'll be able to post some wiring diagrams? I'm curious about the injectors wiring and which custom pins you're using for what. :)

no need to post it, the diagrams are on the megasquirt website.

Here it is from that site:

http://www.megasquirt.info/ms2/v3ext_wiring.gif

Parastie,

Here's a modified schematic I put together a while back. If you use a modified CAS (knock 2 opposing teeth off the 24-tooth wheel), then all signals can be fed nicely through the DB37, rather than requiring extra wires/connectors. Ign #1 thru #3 are the three ignition outputs to leading, trailing, and select wires on the FC ignitors. A-In is a spare analog input for datalogging fuel pressure, compressor discharge temp, or whatever. E-Fan is the electric fan output. The tach signal on pin 24 shows connection to the coil -ve terminal, but would actually be the +ve VR sensor lead from the 24-2 VR sensor in the CAS. The -ve VR sensor lead is terminated to ground at the upper row of DB37 pins.

For those needing more pins, it is possible with some care to remove the ground traces from some of the upper pins, and use those as well.

on the v3 board, it's not necessary to remove any ground traces. 4 of the 2.2 ground pins have been turned into extra spare pins, and come out on vias directly above the MAP sensor.

I'm using the second trigger on the v3 board without any extra connectors by making use of all almost all the available extra pins for ignition, and CAS... and I still have a few spares left.

I haven't posted any kind of diagram b/c I basically did most of what the above diagram did, except I didn't use the IAC pins for IAC (they have to be jumpered to the MS2 to use them, I jumpered them for my own use instead), and I used some of the other extra pins as well... there are at least 9 extra pins that you can jumper internally (if you don't solder in the IGBT circuit), and I think there may be a couple others I'm forgetting about.