Megasquirt & Emissions Testing

[BLOZ UP]

So, has anyone passed an emissions test with Megasquirt?

 

I moved to DFW, where they do an ASM test. I need to get my car inspected before I can get it registered. So, I tuned it to what I thought was stoich, and tried my luck.

 

I passed the safety inspection, but failed the emissions:

 

15 MPH (1500 RPM) test:

HC (ppm): Reading: 255 - Standard: 157 Fail

CO (%): Reading: 4.37 - Standard: 0.88 Fail

NOx: Reading: 182 - Standard: 1184 Pass

 

25 MPH (2500 RPM) test:

HC (ppm): Reading: 247 - Standard: 152 Fail

CO (%): Reading: 6.54 - Standard: 0.97 Fail

NOx: Reading: 133 - Standard: 1082 Pass

 

It read real rich. I datalogged the entire "dyno run", and ran the VE analyzer on it. It really was rich (11.5 - 12.5:1 for each part).

 

So, in Texas you can retest your emissions for free within 15 days of your first test if you fail. The guys at the inspection place are helping me out by "aborting" the test if it looks like I'm about to fail. This way, it doesn't "use up" my free retest. The only way to tell if I'm about to fail (the guy tells me) is if the test "takes longer than about 30 seconds". There's no indication of emissions output until the entire thing is done.

 

So, first, can anyone tell me if that's true? I datalogged the second try, and it was dead on stoich during it, so I'm tempted to just tell them to run the test all the way through, and see the results. But if it fails, I have to fork over another 40 bucks to retest.

 

Second, is 14.7 the sweet spot for emissions? I thought so, but I'm tempted to lean it out to 15.5 or so, and see what happens. My NOx were really low, so I figure I have room to play with.

 

The car:

1988 300ZX

VG30ET, no EGR, air pump, or really any emissions stuff, except a new cat.

 

Attached are my logs and msqs for each test.

blozup-inspection-logs-msq.zip

 

Test 1 is from about record 19360 to 22580

Test 2 is from about record 12520 to 13900 (aborted)

[BLOZ UP]

Hm, no one's done emissions with megasquirt?

[letitsnow]

This site is mostly s30's, so not many have. I personally haven't, but I do remember hearing some advise to someone else to tune for stoich and retard the timing a bit.

[randy 77zt]

lean it out some.i used to have a smog license in california before moving on to trucks/fleet work(more money).the machines in cali had a manual no test mode -see what the operator can do with his machine.the dyno puts a little more load than if you were normally driving the car on flat ground at 15 and 25 mph.that would be pulling less vacuem on the map sensor.as you lean it out the nox will go up some-but you have alot of room on the nox.i have my innovate wide band running a dash gauge and my ms at the same time-so i can have an idea about what is going on with out a computor.if the engine has good ignition and clean injectors the ms should make it pass smog very easy.if you are running rich you will kill a cat convertor.it should pass with out a cat if its tuned right.in cali they check to make sure all parts are oem-so that kills the ms idea.

[akuma-z]

I usually get my inspection taken care of when I go back home to visit my family. They live in a small town in Texas that doesn't require emissions testing. This has saved me from a few headaches in the past. I think I ended up saving like $28 since you only pay for the safety inspection portion.

[BLOZ UP]

I usually get my inspection taken care of when I go back home to visit my family. They live in a small town in Texas that doesn't require emissions testing. This has saved me from a few headaches in the past. I think I ended up saving like $28 since you only pay for the safety inspection portion.

 

That's what I would do (I used to live in San Antonio--no emissions testing), except the law now states that the car has to be inspected in the same county it's registered in.

 

Although, it isn't registered yet so I'm tempted to trailer it out to a no emissions county and get it inspected. But I have a feeling they won't like that at the tax office.

[jc052685]

Lean it out just around the rpms and loads they test. Got a budy with a Starion and it has zero emissions stuff. Not even a cat and it passes smog every time and every time the say "wow this thing is clean!" lol. After the smog test he just reloads the old tune.

[BLOZ UP]

I passed. Yay.

 

I did two tests, one was just a "voluntary test", that didn't count for anything. I passed that, so I tried my luck right afterwards.

 

I added 1 gallon of denatured alcohol to my tank, which was at about 16 gallons (I thought it was at less than half, but I went to fill up right afterwards and it only took 2 more gallons. I retarded the timing 8 degrees across the board. I leaned out the test areas a few more clicks too, during the voluntary test, and it started missing during the low speed one. I richened it back up a couple clicks before the next one, and it cleared up. But I barely passed the second time.

 

Round 2: Pass

15 MPH (1500 RPM) test:

HC (ppm): Reading: 110 - Standard: 157 Pass

CO (%): Reading: 0.01 - Standard: 0.88 Pass

NOx: Reading: 363 - Standard: 1184 Pass

 

25 MPH (2500 RPM) test:

HC (ppm): Reading: 123 - Standard: 152 Pass

CO (%): Reading: 0.01 - Standard: 0.97 Pass

NOx: Reading: 250 - Standard: 1082 Pass

 

After that test I richened up the table at those points just a couple of clicks (two percent). That almost made it fail for the real test (it was bucking on the dyno):

 

For some reason, the high speed test results all came back as zeros. Works for me. Look how close the HC was, just from getting it back down to stoich-ish (the alcohol leans it out a lot)

 

Round 3: Pass

15 MPH (1500 RPM) test:

HC (ppm): Reading: 155 - Standard: 157 Pass

CO (%): Reading: 0.01 - Standard: 0.88 Pass

NOx: Reading: 319 - Standard: 1184 Pass

 

25 MPH (2500 RPM) test:

HC (ppm): Reading: 0 - Standard: 152 Pass

CO (%): Reading: 0.00 - Standard: 0.97 Pass

NOx: Reading: 0 - Standard: 1082 Pass

 

Here's a log of the tests (he had to restart each test a few times because the tach signal for the dyno kept going out): http://krovisser.com/stuff/blozup-emissions-pass.zip

 

Now I have a full tank of fuel that I have to burn off... without flooring it.

[randy 77zt]

test 3 at 25mph looks like the probe was kicked out of the pipe.but if it works thats all you want.just think what it takes to get a new car map written to pass emissions-but thats what auto builders have engineers for.before ford came out with the gt i looked at a pre-production car getting gas at a station in lake havasu az.an engineer was driving it and it had a lot of computor equipment riding in the passsenger side.it was a shock to me to see the car out on the road .trying to get my ms to run that good has been a problem though.

[Nismo280zEd]

Props for you for going legit! Good to see MS is capable of dialing in for "The Man"

You said you retarded timing 8 deg, not sure what timing you were running, but doing so would actually richen you mix, sounds like it was a little too retarded if it was bucking. Probably would have been fine kicking back like 3,4 deg timing. At anyrate, save the map for next year and load up your old map and go use up that fuel!

 

Also... I've heard adding the rubbing alcohol actually increases values?

 

-Ed

[BLOZ UP]

Props for you for going legit! Good to see MS is capable of dialing in for "The Man"

You said you retarded timing 8 deg, not sure what timing you were running, but doing so would actually richen you mix, sounds like it was a little too retarded if it was bucking. Probably would have been fine kicking back like 3,4 deg timing. At anyrate, save the map for next year and load up your old map and go use up that fuel!

 

Also... I've heard adding the rubbing alcohol actually increases values?

 

-Ed

 

Perhaps it was a tad too retarded. But I also had a pretty aggressive map. Here's more or less what I changed (not exactly what I was running but close):

 

From:

 

 

To: