ECMlink SD WOT pull suggestions?

[Marchev]

Hey guys, I'm having some issues with wot tuning that I can't seem to get rid of. After about 6k rpm, AFRs dip into the mid 10s, even thou I have already leaned out my SD table a few times. My SD table seems to lose volumetric efficiency very rapidly after 6k rpm. Any idea why that is?
Also it seems like I'm hitting fuel cut at high rpm. My fuel setup is more than enough for the 16g I'm using, so I really don't understand why my injectors are shutting off at redline. The only thing I can come up with is battery voltage is dropping to 13.0 at WOT, can this cause injector malfunction?
Disregard the knock that is present at the second log, that has already been taken care of. Pulls were done on 93 oct/ 10% ethanol fuel. BLT has been done. Map sensor is tapped on the back of the IM with a direct, short hose leading to it. Mechanical timing is at 5°. Mods are up to date in profile.

Suggestions?

 

[c2ypt1c]

I was just taking a look at your log and noticed the injectors are turning off when your clutch switch turns off...if you're definitely not tapping the clutch by mistake, check the wiring and make sure it's soldered up properly.

EDIT: actually it looks like they start acting up a half-second before the clutch switch so maybe it was just your reaction to it. Try disabling clutch-cut switch to rule it out...

In terms of the rich condition, my gut says your global fuel is off, considering the 10% ethanol variable. Right now, you're global is set for 1226cc injectors...when you add ethanol, stoich is decreased. Essentially, it should be configured for *smaller* injectors (ethanol requires more fuel for stoich), so that is a red flag in itself. I'll dig into it a little deeper and let you know.

And when you say 10% ethanol, do you mean 10% of a full tank is e85, or what?

 

[Marchev]

Good call on the clutch cut switch, I didn't notice that. And I do have a habit of resting my left foot on the clutch pedal when doing pulls, so that might be enough to trigger the clutch switch. Ill disable it today and try it again.
As far as the ethanol is concerned, here in Chicago every gas station has 10% ethanol in every fuel. On the pump itself there is a sticker that says "up to 10% ethanol in every grade of fuel". I'm guessing it's for cleaning purposes. So basically assume there is 90% gas and 10% alcohol in every drop of fuel.

 

[gofer]

I can't look at your log at work but if your injectors are shutting off at redline then your rev limiter is probably set for that RPM, move the rev limiter if you want to go further into the RPM band.

It's common to see a significant VE drop in the upper RPM's, if it's richening up either lower those values in the SD table or use the sliders to pull fuel.

Every gas station advertises a 10% ethanol mix in their unleaded gas, you're running straight 93 oct.

 

[Marchev]

I can't look at your log at work but if your injectors are shutting off at redline then your rev limiter is probably set for that RPM, move the rev limiter if you want to go further into the RPM band.

They shut off at random rpm, sometimes at 6k, sometimes at redline etc. The rev limiter is set at 7500, so I doubt it's that. I really think it's the clutch cut limiter since I rest my foot on the clutch and that might be triggering the switch. Will find out tonight.

It's common to see a significant VE drop in the upper RPM's, if it's richening up either lower those values in the SD table or use the sliders to pull fuel.

It seems like it jumps around a lot, at 5500 rpm I reach ~101 VE and by the time I get to 7k I'm down to ~69.
So you're saying that to keep the SD table smooth, it's ok to pull fuel with the sliders under the "fuel" tab?

 

[lil corb]

They shut off at random rpm, sometimes at 6k, sometimes at redline etc. The rev limiter is set at 7500, so I doubt it's that. I really think it's the clutch cut limiter since I rest my foot on the clutch and that might be triggering the switch. Will find out tonight.


It seems like it jumps around a lot, at 5500 rpm I reach ~101 VE and by the time I get to 7k I'm down to ~69.
So you're saying that to keep the SD table smooth, it's ok to pull fuel with the sliders under the "fuel" tab?

Try to stop the bad habit of resting your foot on there. That's the only thing that makes sense as to why it cuts out unless you have electrical gremlins somewhere.

 

[Marchev]

Update
So I went out for a few runs tonight and sure enough everything is fine! Looking at the captured log the injectors did not shut down like they used to.
I also looked at the majority of the old logs that I hit that mysterious fuel cut, while logging the clutch switch, I noticed the injectors shut off exactly when the switch gets triggered.
Thanks for helping me find the issue!

 

[c2ypt1c]

Cool man! However, I'm suspicious something else might be going on because the injectors are getting choppy in the ~69 area on the VE table. You can see your AFRatioEst is getting choppy causing your WBFactor to do the same, pulling your VE values down...and it doesn't look like the clutch switch is causing this. Post an updated log wot from 3k to redline.

 

[gofer]

They shut off at random rpm, sometimes at 6k, sometimes at redline etc. The rev limiter is set at 7500, so I doubt it's that. I really think it's the clutch cut limiter since I rest my foot on the clutch and that might be triggering the switch. Will find out tonight.

It seems like it jumps around a lot, at 5500 rpm I reach ~101 VE and by the time I get to 7k I'm down to ~69.
So you're saying that to keep the SD table smooth, it's ok to pull fuel with the sliders under the "fuel" tab?

After reviewing your tune it wasn't the rev limiter and the NLTS diagnoses is probably the most accurate, especially since you've recently done a pull and conscientiously kept your foot off the clutch pedal. You may crawl under the dash and see if you can't thread the cruise control switch further out of the pedal assembly so it isn't so touchy. If/when you do decide to activate NLTS again, be sure your launch limit RPM is lower than your NLTS RPM. If it isn't the second you launch the car will assume you're trying to shift as you slip the clutch and you'll never get off the line...

I don't recommend touching the fuel sliders but if it bothers you that the increments in the SD table transition too quickly then you can keep the SD table smooth so it looks nice and use the sliders.

I don't know your mods but there are a of things to help increase VE and it's pretty normal to see VE numbers dip like that after the motor reaches peak volumetric efficiency. Your AFREst and AFR's line up well, who care's what the VE table looks like?

 

[Marchev]

Cool man! However, I'm suspicious something else might be going on because the injectors are getting choppy in the ~69 area on the VE table. You can see your AFRatioEst is getting choppy causing your WBFactor to do the same, pulling your VE values down...and it doesn't look like the clutch switch is causing this. Post an updated log wot from 3k to redline.

I noticed that as well, however even with the old setup the injector duty was never a perfectly smooth, linear ramp.
I will post up an updated log in the late afternoon.

I don't recommend touching the fuel sliders but if it bothers you that the increments in the SD table transition too quickly then you can keep the SD table smooth so it looks nice and use the sliders.

I don't know your mods but there are a lot of things to help increase VE and it's pretty normal to see VE numbers dip like that after the motor reaches peak volumetric efficiency. Your AFREst and AFR's line up well, who care's what the VE table looks like?

I would rather not mess with the sliders. As long as it's normal for the VE to drop like that, I can live with it.
Besides cams and port work, what else can increase the efficiency of the engine?

 

[gofer]

SMIM, oversized valves, bigger hotside, bigger/no exhaust...

 

[c2ypt1c]

As long as it's normal for the VE to drop like that, I can live with it.

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This is not normal. Notice the spike in AFRatioEst (blue line) and WBFactor at -22.0%. This is why his VE values are going so low, and it's happening before the clutch switch (green line) hits 0. Maybe his foot is hitting the switch faster than the sample rate of the logger?? We need another log with clutch cut disabled to find out.

 

[Marchev]

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This is not normal. Notice the spike in AFRatioEst (blue line) and WBFactor at -22.0%. This is why his VE values are going so low, and it's happening before the clutch switch (green line) hits 0. Maybe his foot is hitting the switch faster than the sample rate of the logger?? We need another log with clutch cut disabled to find out.

The log looks very similar even with the clutch switch disabled. The AFRest jumps when the IDC dips for a tenth of a second, but the wideband reads steady. I will post a current log when I get home

 

[gofer]

Once again I'm at work so I can't open a log but typically those AFRatioEst spikes occur because the SD table cells aren't smooth, which I remember being the case last night when I glanced at the log. You may also try checking the "Enable airflow smoothing with SD..." box in the Misc tab...

 

[Marchev]

Here is a log from last night with the clutch switch disabled. The injectors don't shut off, but there is that spike that Phil was talking about. I think Corey might be onto something because if you track the VE table, exactly when AFRest spikes, the ecu is jumping from a cell with 76.5 VE to another with 70.5 VE

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[gofer]

Your AFR's are solid so I would tune out the knock by lowering timing where it's knocking and call the tune good if you're happy at 21 psi.

To smooth the SD VE table highlight a few cells that need smoothing and right click the highlights section, then select "interpolate..."

 

[c2ypt1c]

Yeah, I agree. After digging around the ECMLink forums I noticed Dave's recommendation for a spiky AFRatioEst:

I would enable airflow smoothing with SD operation (Misc tab) and configure the AirflowSmoothing direct-access table with something like 30% for all of the values.

(^that thread has some good info)

Hopefully that'll clear things up

 

[Marchev]

Awesome! Thanks a lot guys! I will read through that thread and make the suggested changes.