Justin Pezzack

Just looking for a sanity check, no access to a dyno at the moment. Will just be doing ve analyze to begin. Leaned out around 3.5-4k RPM as that is what I cruise at on the highway. Could I go leaner at WOT?

Built the AFR table myself, the spark map is from a base map I got with the ECU from DIY autotune.

Fully stock 1.6
949 Racing U-Bend intake
Racing Beat Header - Test Pipe - Race Exhaust
91 Octane

18psi

iTrader: (76)

Those are bad. You want richer at wot, and that spark table terrible. A car should never be run at basically two timing values across the whole range.
DIYauto is known to have put out some truly bad spark maps in their base maps, that should never be used to drive on. Look around, you'll find proper ones or at least something safe enough to start with.

Ted75zcar

iTrader: (2)

Maximum fuel economy occurs at ~15.4 for ethanol free gasoline (Stoich of 14.7). Running any leaner that that actually consumes more fuel and increases the likelihood of spark knock.

18psi

iTrader: (76)

And targeting a superlean mixture isn't nearly as important as getting the car to actually hit the targets quickly and consistently.

Justin Pezzack

Thanks for the feedback guys.
Adjusted WOT to start at 13 and go down to 12.7
Brought leanest sections of the table down to 15.3
Spark map modelled after reply #2 of https://www.miataturbo.net/megasquir...gnition-71921/ by @Joe Perez . Took a few degrees out up top just to be safe. But Joe getting your thoughts would be dope.
Still feeling kinda lost on the spark without a dyno, but it is what it is.

andym

your spark map is too far advanced. I'd look to reduce your entire map by nearly 5 degrees if not more in certain spots. How are you listening for knock do you have det cans or a knock sensor?

andym

I am not holding out my spark map as the end all be all of good, I know it needs some more work but this is more or less what I run.I have an 03 engine so my compression is higher than yours which means my likelihood for detonation is a bit higher, but I think a table like this would be a good starting point for you.

LeoNA

Highlight the whole ign map and use the - button to subtract 8 degrees, then highlight the whole 1000rpm colum and add 8 back with the + button. That will put you in the ball park. These engines in NA form make the most power around 30 deg. The lean cruise area needs to be in the upper 30's for an AFR of 15-15.7. If this was a max effort MPG vehicle you could go further, but that's not for most.

18psi

iTrader: (76)

That is a decent looking spark map to start with, Andy

LeoNA

I agree Andy's is ok but Justin's is terrible. On Andy's the upper left and lower right quadrent are a bit extreme though.

Below is something I threw together that is similar to what I ran on my NA 1.6. This was on 91 CA gas and with an idle at 900rpm. I left them with the axis value view so that someone who is new to tuning can see how to change these values. It is important to have the ranges similar to each other, AFR, VE & timing. Also to have the correct range. Many newbies have ranges that limit incorrectly. No need to start at 10kpa which is not achievable and finish 150kpa if your not FI. Also I prefer to have a specific RPM that matches the idle.

Justin Pezzack

I'm quite confused about why going to 36-40 degrees at WOT redline on 91 octane is an issue.

As quoted by @Braineack on miata.net https://forum.miata.net/vb/showthread.php?t=303941

This is stock timing on 87 Octane

Call me crazy? Thoughts?

Re knock sensing, I am in the process of building det cans.

18psi

iTrader: (76)

The craziest part is just guessing numbers based on someone else's guesses and then just running with them without a single proper test or way to check that it's not dangerous.

The stock ecu also runs a narrowband, and also runs stoich all the way to midway of powerband. That should not be your standard. if you're advancing timing but not seeing any gains, even if you don't see knock, you're putting completely useless stress on your internals.


If you want to try stuff for science, I fully support this, but make sure to disclose it as such so that clueless n00bs in the future won't use your stuff as standard cause they're too dumb to know any better.

Justin Pezzack

@18psi yup makes total sense, I'll load up andy's spark map and go from there, priority should be getting fuel down anyways.

I find my car cruises on the highway around 75-80kpa, on @LeoNA 's map that would put me in the mid 13's, is running the 15.3 that high like in my map okay? Or tbh I guess that is something det cans and EGT'S is going to tell me... gotta put the time in.

Justin Pezzack

Documenting the next steps for completeness sakes. Built spark table similar to @andym 's scaled down for 12x12 on MS2. Minor tweaks to AFR table in some low RPM areas.

andym

If your car were mine I would not run 15.3 between 72 and 83 kpa. I'd richen that up a bit so that it is a more gradual transition. The difference between 83kpa and 90 isn't very much and you are jumping 2 whole afr points there. I'd work on your bubble of afr table so that it is a bit less lean from 72kpa and up around your 3500 to 4000 rpm range. Maybe target 14.7, then 14.3 then 13.8 then 13.2 then your 13.1 and 13 rows. Also, I run a bit richer at 100kpa. Roughly 12.6 to 12.7 Your results may vary.

LeoNA

I was running 50-70kpa at cruise and for the smaller 100hp engine it seemed to be more efficient near stoich. Stoich for E10 91oct fuel is about 14.4. I also tuned it more towards power then MPG. Max power is around 12.5-13. I was tracking my car at Buttonwillow sometimes at 90+ degrees. If fuel economy is your goal you could run well into the 16+:1 range with 38-40 degrees, but why, to maybe gain 1mpg extra. The beauty of a stand alone is to be able to tune for more power and better drivability. The OE ecu is tuned to meet emission and CAFE regulations.

Justin Pezzack

Makes sense, smoothed it out a bit, are there any rules of thumb about the magnitude of the slope of the Y-Z plane? units of AFR per Load %? How does that look? Wish I had better intuition but that is something that will come with time I hope. For instance between 85 and 90kpa I am still jumping 0.9, is that to steep still?

andym

If it were my car I would try richening it up a little bit more but it is starting to look better. Also, your idle areas look very rich. Any particular reason why? Are you also running idle ve and tuning that?

Justin Pezzack

My car is still running batch injection, the car seems to be happy idling in the 13.2-13.4 range, I tried leaning out to like 13.7-14 and it started getting upset. The injectors are 30 years old, it is what it is for the time being. At some point I should do the modifications to go sequential injection but it doesn't seem pressing atm. Ill richen up the 3500-4000rpm "peak" a tenth or two and see how it goes.

Do you think idle VE is worth doing? I didn't really see the point, but I am also serious tuning noob so there is that.

Not to throw more variables at it, but I do have a set of ID1050's around since I was planning to go FI once until all this COVID stuff blows over (getting parts has been brutal here in Canada atm). Would it be worth throwing them in now? I've heard modern injectors help with drivability and make tuning things a bit easier, but also seems super duper crazy overkill right now.

LeoNA

I don't run idle VE. I ran Flow Force 640's and a DW200 pump with my NA16. A friend of mine is running ID1050's with his stock NA1.8. Mainly because he occasionally runs E85.