rotarygod

I went back and checked, we did try that wire. That was the first one we tried. The voltage range was easily wide enough but it doesn't hold that voltage there if you hold the throttle in one spot. We can try it again.

I love technology. I am in a conference call right now!

swoope

iTrader: (5)

words of encouragement.

beers

rotarygod

Oh man I love Megasquirt! I was playing around in Megatune (the tuning software) and noticed an option which I can use with absolutely no modifications to hardware or wiring whatsoever. It is called mapdot tuning. I am currently using tpsdot tuning. What mapdot allows me to do is to completely tune the car based off of map pressure during acceleration. tpsdot is a combination of tps signal and map pressure. What this means for us is that I do not need a tps sensor to make the car run!!! YAY! Don't have to worry about that wiring problem anymore. There isn't one. This little ecu just keeps getting nicer and nicer. All I have to do is make a quick change in the tuning options. I'm doing this anyways by tuning the car. I will get used to tuning it this way on my RX-7. I'll play with it tomorrow (today, it's 2:15 am). Then I'll get Alan back over here to try it out. This means that the RX-8 should fire up with full Megasquirt fuel control in the VERY near future! I don't even want to go to bed right now I'm so excited about this. Too bad I can't work on it right now.

Stay "tuned"...

stever

Sounds encouraging, great stuff!

Longhornxtreme

I had discovered that option too when playing around with Megatune... I remember reading somewhere (MS forums) that for FI you want like a 20%-80% TPS-MAP for your Accel and Decel settings...

I hope we can get this to work off of just the MAP tuning so we don't have to mess with the TPS...

I still do'nt understand how the Greddy can pull working TPS and MS can't thouhg...

rotarygod

Actually I may have been looking for the wrong thing when I was testing all of the tps wires with the meter. I was looking for a signal wire that always gave you signal for where the throttle plate currently is. That actually isn't important. All we need a tps sensor for is to determine acceleration enrichment. Even this is only just spraying a small amount of extra fuel for a few milliseconds to account for the sudden rush of air when the throttle is opened. The car always runs on the maps. Since this is such a short amount of time, it is irrelevant if I continuously get a signal from the tps or not. The ecu will only compensate with accel enrichment for this split second. After that the value is worthless. I just understood it wrong and tested it wrong. We probably can use one of the wires. That will involve going back and testing them all again. I'm just going to play with mapdot to see how well I can get it running first. If it works good, there's no reason to use the tps. There are many MS users that apparently aren't even using tps anymore. That's just one less wire to tap into if I can do it this way.

I'm going to wire up the harness to the injectors so we can actually try to get the car started. Hopefully we'll try it within the next day or 2. IF this all goes well, I will tune in a couple of fuel maps based on a/f ratio. I want one at 12.5:1 across the board and another at 13.0:1 across the board at full throttle. I want to be able to do some timed runs with the stock ecu and both of these maps to see if there is an improvement. We still don't know if the factory ecu is going to mess with the timing adversely or not. We'll know soon though.

rkostolni

Wont' it be a problem that the ecu will see excessively rich a/f (11.5:1 for turbo'd 8's) on the O2's and will try to adjust it back to stoich, but won't be able to? It seems to me this would at least throw a cel.

rotarygod

It may or may not be an issue. I'm not tuning for forced induction right now. We fully expect to get a CEL until we get the a/f tuned in good. Hopefully after that we can reset the CEL and everything will be fine. If it's only a CEL that pops up and not a problem with the way the car runs, I'm not really concerned. Our system literally just plugs in in less than 5 minutes and can be removed just as quickly. No issues for inspections this way.

Richard Paul

iTrader: (5)

That is exactly what I was trying to say when I called it an accelerator pump wire.
Sorry I related to carb lingo but I'm too old to change now.

rotarygod

I thought we'd have a chance to get it fired up tonight but we didn't. It will have to wait until Saturday.

rotarygod

The day has arrived. The world's first Megasquirt powered RX-8 runs!!!

I guessed, yes guessed at the values to enter into the MS. When Alan went to start up the car, it started like it was running off of the stock ecu. We looked at each other and wondered if it was. The only difference is that it was running better at idle off of the MS than stock! We found that Mazda runs the stock ecu a little lean at idle and too rich everywhere else. By richening it up just a little bit at idle, it idles very smooth and holds a nearly perfect 825 rpm idle. Actually it was between 815-830 but who's counting!

As I changed the a/f ratios, we could watch the wideband through canscan to see exactly what I was doing. Talk about being easy to tune! The stock timing was not affected in any way nor was anything else that we know of. Here's the best part, we got NO ERROR CODES!!! None. No CEL's. The car had no clue what we were doing. Even when we plugged the stock ecu back in, still no error codes.

Alan had to leave pretty quickly so we only had a few minutes to play around. The next step is to develop a nice map or 2 and then compare them to see what the car likes and also to verify how everything works. So far everything has worked exactly as we thought it would! Today is a very good day full of lots of promise for the future.

Mazda, I have gotten around your ecu. You guys are now officially my bitch! To add insult to injury, I've done it with an 8 bit ecu vs your stock dual 32 bit unit and mine runs better! HA!

neit_jnf

flame me all you want but... is the car turbo or n/a? I'm waiting to see this or Mazport's unit tuning a stock car!

nijelSC

Congrats, RG. You are the MAN.
How do you intent to tune it, I mean with no dyno? Just putting AFR like is suppose to be, with no real feedback what are you doing? Just curios.
And get the ignition done too. :D

TexasKyle

Holy Hell! Awesome job guys. Richard (along with all of us) is probably smiling big time right now.

TexasKyle

Just thought of something...Once the guys that make it find out how well it is working for the 8...the price will probably double! hahahahahaha.....

brillo

Hehehe

Mazda is my bitch....

Yeah we were pretty impressed with the ease of tuning the car at idle, the ignition didn't change from stock (its still running -5 at idle) and the car appears to not really care what we are doing prolly because we are operating in a safe range of ~11-14:1 afr.

for Neit_inf, my car is totally NA. I don't really feel that this is a competition with Mazsport, they have what appears to be a great product, with more features than the MS will have that pertain specifically to the 8. The MS working is almost more important not because the MS it self runs, but its proof that other ECU's can as well on the car. The MS is a neat unit, and will be a solution for some folks but not all. We still need to work out some driving maps and of course get the ignition working before this could ever help the FI guys. But were are getting closer everyday.

I hope that by 7Stock we can have a good working fuel tune and hopefully have the ignition started as well.

rotarenvy

good work!
this work paves the way for other engine managment systems as well.
I hope the warning lights stay off :D

neit_jnf

thanks, I got confused by the thread title

what afr's are you planning to tune for? 13~14:1 at wot?

swoope

iTrader: (5)

excellent job gentlemen!!!

beers

Moostafa29

Congrats guys!

rkostolni

Will this be well suited to be used on a turbo'd rx8? Will it lack any critical functionality that the interceptor has? I am definitely going to be getting myself one of these if this works out!

Longhornxtreme

Everything sounds just great!

I can't wait till my car is running MS, maybe we'll see the fuel economy come up a little...

I can't believe that this thread came to fruition!

Keep us updated and make with the how to

brillo

theoretically, the MS should be suited to help tune any light to medium turbo/supercharger (6-12psi), asssuming we can get the ignition side of the system working. I give that range b/c the maps are only 12x12 right now, and the more boost you run, the more fine tuning you will need.

The MS does not have some of the features of the Mazdasport unit, we can't yet adjust the VDI and Aux intake ports, and you will have to upgrade the spark coils since the MS runs wasted spark mode, which will likely burn out the stock coils.

I don't expect a fully functional megasquirt with ignition til Nov/Dec, given that RG needs to get the parts for the ignition side, set it up on his first gen to learn the system, then we will take the project to my car. In the mean time, we can try to make some maps up for the fuel side, but the ignition tuning is rather critical for you FI folks.

rotarygod

The MS does have the ability to control VDI, the aux ports etc... I just don't have it wired up to do so. I would have to build a small driver for a few bucks to do it and add it to the ecu but that is easy. I've just decided to leave that area alone but it can be done quite easily. May try that in the future at some point but I feel it is more important to get it working good first before adding features to it.

I'll do a "how to" after I get it all completely worked out. Right now I would have to go back and do a "how did?".

rkostolni

Wow, Nov/Dec time huh? What is it that is going to take so long? Any way us forum members can help speed that along? Maybe donations to help pay for parts, or researching wiring diagrams, just name it if it can help get this along. I am dying to get this emanage out of control!