Miata Turbo Forum - Boost cars, acquire cats.

Miata Turbo Forum - Boost cars, acquire cats. (https://www.miataturbo.net/)
-   E-Manage (https://www.miataturbo.net/e-manage-10/)
-   -   Anti stall map? (https://www.miataturbo.net/e-manage-10/anti-stall-map-12710/)

piratetim 09-18-2007 01:49 PM

Anti stall map?
 
Can someone explain how the anti stall maps works? along with 02 clamps cause im guessing thats what it is.

Joe Perez 09-18-2007 02:03 PM

From page 32 of the operating manual:
Anti Engine Stall Setting
• This feature is used to prevent engine stall caused by turbo blow back to the airflow meter.
• Input the Throttle Position point which will activate this feature for the set amount of time. When
the throttle position is below the inputted point, the e-manage Ultimate will recognize the
accelerator as closed and will clamp the airflow meter signal going back to ECU.
Sounds like this isn't going to be relevant in your case, though it seems straightforward to try.

The T.P. box indicate what level the TPS must be below for this to activate. The manual says to use 1%. If your TPS is less than perfectly calibrated, maybe 2 or 3% would be better.

The Time box indicates how long to hold the anti-stall value on throttle closing, before releasing back to normal. Values are 0 to 5 seconds, in 0.2 second increments. Maybe try 2 or 3 seconds and work from there?

The row map at the bottom is easy- for any given RPM value, hold exactly the indicated AFM voltage while the anti-stall is active (TPS and Time parameters are met). I'd put in whatever voltages indicate normal idle at those RPMs.


O2 clamp is an unrelated subject. Has to do with preventing the engine from going lean at the transition into boost and at low boost levels. We covered it just recently over at M.net: http://forum.miata.net/vb/showthread.php?t=249854


Regarding the MAF removal- I'm really excited to see someone else picking up the torch and making this happen for the NB. I've had people ask me if I was ever going to do an airflow map for the 1.8, and I've always had to say "Sorry, I don't own one." Hopefully you'll get this all ironed out and create a nice walkthrough that everyone can benefit from. Best of luck.

piratetim 09-19-2007 02:37 AM

Well today was a huge turning point for me. The car moved!!!

I am definitely running no MAF which I guess is pretty cool for the NB. Im still having trouble getting my LC1 to be recognized by my EMU. I went to radio shack and bought a micro mini jack stereo to mini jack stereo. I plugged the small one into my LC1 and the other end into the EMU....its not showing nay af numbers in my data log.

So anyways ive been doing this blind. Having my a/f ratios run beside my emanage tool as I drive and tune from there.

Our problem tonight was getting + boost numbers(remember this was the first time we have ran the car). We found that my BOV is missing the O ring so that will go in tomorrow and I can actually start building boost. Otherwise we have the map smoothed out enough to basically feel stock running

piratetim 09-19-2007 02:38 AM

It took us awhile to figure out the airflow output setting. The manual says use this to force it into open loop. it took us about an hour to figure out what to do with the thing. Well we hit enter and turned all the off's to on's. Were guessing ON means no more closed loop?

Oh and Joe thank you for your help so far this week. All of your replies have helped out a TON.

Joe Perez 09-20-2007 06:09 PM

Resurrecting an older thread here because I'm very confused by something.

You mention changing OFF to ON with regard to Airflow Output. What screen is this on exactly? The Airflow Output Map is just a regular 2d grid with numeric values in it, and I can't immediately see any other setting where this makes sense to me. So where were you editing when you saw this?


As to open loop vs. closed loop. When dealing with the stock ECU, we cannot necessarily force it into closed vs. open, nor can we know with certainty which mode it is operating in.

We can infer whether it is running open loop or closed loop by observing AFR (absent any correction) or by looking at airflow vs. RPM and making an educated guess based on the fact that we know it switches to open-loop at some undisclosed point on its load map (and not merely when it crosses 4000RPM or senses WOT, contrary to popular belief)

As to controlling it, well, we can't. There's just no way to force the ECU open-loop without causing a fault code in the process. The best we can do is use things like O2 sensor clamps to prevent it from doing stupid things when it is (or might be) in closed-loop mode.

piratetim 09-20-2007 06:23 PM

It says in the back of the EMu manual that you cant make changes on the af target map in non boosted areas b/c the ecu is in closed loop. But to force the ecu into open use the aux output setting map. When you open this map it says off...you hit enter it turns it on. Maybe im just confused

Joe Perez 09-20-2007 06:49 PM

Ah HA!

Ok- the book is right about the A/F Target Map. In fact, this was one of the big problems that badboy was having a short while back. If you have any value other than "-" in the A/F Target map that is in a cell which is active during idle or normal cruise, then the EMU and the ECU will be constantly fighting each other- one trimming fuel up, the other trimming fuel down. Makes the I/J tables look like hell and doesn't exactly help the engine either. On the other hand, there are times when we do want A/F Target active (while in boost) and since we don't know for sure whether the ECU is going to be open or closed-loop at the time, we need to prevent the ECU from meddling in the affairs of the EMU A/F Target Map during those times.

However, simply turning on the Aux Output does not, by itself, do anything at all to put the ECU into open-loop mode. You have to have the Aux Output wire actually connected to something!

The assumption is that the Aux Output is being used to drive an O2 sensor clamp. This is how my setup is wired, and how I recommend that everyone with an EMU do it. So when the Aux Output Map is in an "ON" cell the O2 sensor clamp will be engaged, and with it's in an "OFF" cell, the stock narrowband sensor will feed the ECU.

Understand a couple of things however. Operating an O2 sensor clamp does not force the ECU into open-loop, it merely prevents it from seeing the actual AFR and instead fools it into thinking that everything is just fine. In reality, the ECU is probably going to switch itself into open-loop as a result of its airflow-based load calculation when you are boost anyway, but why take a chance? At a minimum, the switch into open-loop might tend to be a little slow, causing the nefarious lean tip-in that everyone used to lament in days gone by.

And that being said, you do not want your engine to be running either open-loop or on the O2 sensor clamp all the time! When you are not in boost, the NB O2 sensor needs to feed the ECU so that it can actually control the mixture. Otherwise you'll just run pig rich all the time and throw codes.

The proper way to set this up is to have values entered into the A/F Target Map only in boosted cells, and to have the Aux Output Map also set to ON in these same cells. Thus, when you cross into boost the O2 clamp will engage, blinding the ECU to the fact that we are now intentionally running the mixture rich. With the ECU no longer trying to oscillate the fuel around 14.7:1, the A/F Target Map is free to do its business without interference.

piratetim 09-20-2007 07:03 PM

ok now the on makes a lot more sense HAHA

Marc D 09-22-2007 11:50 AM

i wish it were that easy for me. i wasnt getting the results i was supposed to get forcing me to mess with the A/F ratios. anyway, i called up greddy about my problem, but they told me to send the unit to them so they can do a diagnostic on it. it should be back next week.

Joe Perez 09-22-2007 10:58 PM


Originally Posted by badboy88000 (Post 154108)
i wish it were that easy for me.

Well, if it's any consolation, look at it this way. You're having better luck than piratetim who, as it happens, convinced me to stop by Home Depot and purchase a fire extinguisher.

Marc D 09-24-2007 02:19 AM

that does make me feel better ><

thanks

piratetim 09-24-2007 03:20 AM

HAHAHA!!!

anyways. The car is surprisingly good. My new brake cylinder will be here this week. I already have the two new hoses, spark plugs, wires and oil feed line I needed. The last few things i need are a new LC1, dipstick and oil cap.

If the stuff gets here quick enough the car will be running by the end of the week!:)

oh .. and yes I need a new fire extuingisher

Joe Perez 09-24-2007 11:37 AM


Originally Posted by piratetim (Post 155328)
oh .. and yes I need a new fire extuingisher

I tried HD last night, but no luck. They had a nice-looking 10BC model, but it didn't include any kind of clamp or other suitable mounting provision. I really want something I can secure to the floor just in front of the pax seat.

Guess I'll try Lowes this afternoon, maybe NAPA or PepBoys... Someone local has got to carry this sort of thing.

piratetim 09-24-2007 02:58 PM

I bought one of those APC chrome ones from schmuck's. It came with a bracket that I ziptied to my roll bar. And surprisingly it worked great for the fire too!

Joe Perez 09-24-2007 03:39 PM

Schmuck's? Clearly you must have some interesting auto parts stores up there in WA.

piratetim 09-24-2007 05:25 PM

Thats what we call them around here. If you need to ask a question about a part...you might as well just close your eyes, spin around and pick up something random then ask one of them.

mazda/nissan 04-08-2008 10:14 AM

I'm going to revive an old thread rather than create my own. The antistall feature on my EMB can only be used with an incremental TPS, not an on/off like my 1.6 has right?

Jefe 04-15-2008 04:19 PM

I had to use it on my EMB on the P5. (I must have the map on the other computer right now) and it's been a few years...


IIRC, It clamped the MAF voltage so it wouldn't stall at idle using a VTA BOV. I wasn't using the TPS for anything, IIRC you could set it using RPM either MAF V or Greddy Pressure sensor V.

mazda/nissan 04-15-2008 04:24 PM

Sweet thx for the help jefe!


All times are GMT -4. The time now is 05:56 AM.


© 2024 MH Sub I, LLC dba Internet Brands