Throttle decay rate dodge

[Benjamin Lopez]

Hi team, should I have a cal for adjusting throttle decay? may I ask HP tuners to add it for my model, or for Dodge there is not such cal... then how can I deal with the following if anybody can help me?

After I blip the throttle to high rpms and I release, the PCM holds rpms to drop down really slow by retaining throttle from about 20% and slow (6 seconds) decay until iddle: I can see the throttle hangs at around 20% open after I release the pedal and sloops down slowly.

I is horrible ..... I have read its like this in stock modern cars for emissions.... but I just hate it. I see GM has idle cracker where they manage this and I have seen for dodge other programmers have this "iddle decay" cal, but mine does not show any direct way to adjust that. I have seen some ones increase throttle airflow table to reduce this effect, but I think it should be a direct more effective way to cancel this throttle hang?

Thanks!

[vndetta79]

What vehicle is it and do you have a scan and a tune file you can share?

[Benjamin Lopez]

4rev1c garaje chally11v6.hpl

4rev1c camtry2 WOT cam angles for all normal table polished.hpt

There you go. I have seen when the engine is colder its much worst than when on its temp.

ITs a chally 2011 V6

[vndetta79]

Firstly, you need to add "Aircharge" to your channels list in the scanner. You have no load reference for your spark tables. You could use the MAP sensor too but your spark tables reference aircharge on the axis so I like to use that. Would recommend adding MAP to your channels too.
Screenshot 2023-04-21 115231.png

Second, your throttle blade appears to be closing but there is a lot spark advance after you back off the throttle. I don't think your issue is throttle related. I would recommend backing out 10-15 degrees of timing from the top 2 rows of your Base Part Throttle map and smooth it out. See how that goes and continue taking 2-5 degrees out until it's where you like it.

My guess is it needs about 20 degrees taken out. Right now, you have 53 degrees with 5% throttle on deceleration. Too much advance can cause rev hang.
Screenshot 2023-04-21 115359.png

[Benjamin Lopez]

Firstly, you need to add "Aircharge" to your channels list in the scanner. You have no load reference for your spark tables. You could use the MAP sensor too but your spark tables reference aircharge on the axis so I like to use that. Would recommend adding MAP to your channels too.
Screenshot 2023-04-21 115231.png

Second, your throttle blade appears to be closing but there is a lot spark advance after you back off the throttle. I don't think your issue is throttle related. I would recommend backing out 10-15 degrees of timing from the top 2 rows of your Base Part Throttle map and smooth it out. See how that goes and continue taking 2-5 degrees out until it's where you like it.

My guess is it needs about 20 degrees taken out. Right now, you have 53 degrees with 5% throttle on deceleration. Too much advance can cause rev hang.
Screenshot 2023-04-21 115359.png

OK Sir I will try that, first of all thanks a lot.... I have couple of questions: this is the stock timing what you see in that range table (that area you highlight is unmodified), don?t you think retarding spark in low range from stock will make it to bang on deceleration? because I don?t like that.... (but I will try it anyway and see). However if you see to the trending, the throttle reaches 50% and it drops fast until 20% then from 20% something is holding it to close very-very slow: it holds it for 4 seconds in a soft ramp until back at iddle and in the first instance there is not even any fuel injected.

Thanks again.

[vndetta79]

Exhaust crackle requires negative timing so you're safe there.

As for your throttle question you can try the attached file. Your Power % Request and Expected Pedal should be inverse. See if this helps.
Screenshot 2023-04-22 093929.png4rev1c camtry2 WOT cam angles for all normal table polished1.hpt

[Benjamin Lopez]

Vndetta, I tried both things and none gave a perceptible result on the subject.

In fact the last proposed made the car very ugly to drive because of my shifting schedule: nothing that can not be fixed of course... I understand gears shift schedule is function of the pedal, and now that I needing much more pedal for the same throttle makes the car shift at very higher rpms so it would require to reschedule the shifts.... but anyway it did not fix the issue so I returned to my original because I feel better my current pedal response.

Thanks, any other ideas appreciated.

[vndetta79]

Vndetta, I tried both things and none gave a perceptible result on the subject.

In fact the last proposed made the car very ugly to drive because of my shifting schedule: nothing that can not be fixed of course... I understand gears shift schedule is function of the pedal, and now that I needing much more pedal for the same throttle makes the car shift at very higher rpms so it would require to reschedule the shifts.... but anyway it did not fix the issue so I returned to my original because I feel better my current pedal response.

Thanks, any other ideas appreciated.

Did you do a before and after scan to compare? It's hard to help unless you can share some data that also has load scanned.
If you can share a scan that includes Aircharge and P Ratio, it might help to see more of what is going on.
Screenshot 2023-05-15 200134.png
This is from the scan you shared and it shows that you have throttle lag relative to your pedal position when you hit it rapidly.
Screenshot 2023-05-15 201813.png
As a comparison, this is a scan from my Ram where the throttle tables are inverse of each other. The throttle and pedal characteristics are identical. Much like a cable operated throttle. You will notice that when the throttle closed my timing only goes to 27 degrees which is half of your 53 degrees. This scan is in second gear too.

[Benjamin Lopez]

You are right Sir, I entered the file, did a trip with the car and didn?t like it ( mostly because the shift schedule requires big adaption) I pushed the pedal and I noticed same or worst delay in rpm decay than with my file. But you are right: next time I have a chance I will re-load it, warm up, trend and share. If you see the timing of my trends the lag between pedal and throttle to increase I believe is just electronics or reading delay, it is not noticeable at all: but maybe you are right that it can be reduced with the inverse, I will take a look to my inverse calculation too.