2016 Challenger RT Magnuson part throttle surge

[Ditosmotors]

2016 Challenger RT Magnuson SC with 270 comp cam.

I tuned this car about a month ago and I dont remember it having this problem, at least not at wot.

The car surges at part throttle (between 40% and 70%). I can see in the logs that the throttle and timing are fluctuating when it does this. I can also see just before it happens the trans engine torque request changes from none to decrease. I tried disabling the trans ETC and Spark under torque management on the engine side and I also tried raising the Max torque limit on the transmission side. This did not help.

I havent been able to drive it on the street at wot today because of the rain but I know it did not do this on the dyno when I tuned it a month ago.

In the log the problem can be seen starting at 09:17:47

[Ditosmotors]

I tried raising a torque limiter I found in the trans side. Torque management>Gear max limit normal. When I change these the check engine light stays on with code P1DF3, U0402 and P1DD2 Torque Request signal from TCM denied. This puts it into limp mode. Once I put the table back to stop it fine. Not sure if this is a table that if changed would fix my issue but thought I would mention it.

[UHemiNow]

Are you sure your throttle body airflow is correct in that area? Sounds like it may want a little more. I don't think you can see delta throttle with HP or at least I haven't figured out how to but just "guessing" I'd say if you added about 2 gsec from .35 to .75 volts it might help. Hope this helps

[Mark@HPTuners]

2016 Challenger RT Magnuson SC with 270 comp cam.

I tuned this car about a month ago and I dont remember it having this problem, at least not at wot.

The car surges at part throttle (between 40% and 70%). I can see in the logs that the throttle and timing are fluctuating when it does this. I can also see just before it happens the trans engine torque request changes from none to decrease. I tried disabling the trans ETC and Spark under torque management on the engine side and I also tried raising the Max torque limit on the transmission side. This did not help.

I havent been able to drive it on the street at wot today because of the rain but I know it did not do this on the dyno when I tuned it a month ago.

In the log the problem can be seen starting at 09:17:47

If you aren't using VCM Suite 3.7 already, download and install the latest beta. There is a table in beta under Engine -> Airflow -> Electronic Throttle -> Proportional called "Proportional Gain vs Throttle Airflow Error vs PRatio" (Table: 5999 ... See picture below). I was having the same throttle surging problem on my 2015 RAM 1500 with a Magnuson, set this table to 1.00 across the board and the issue went away.

Prop Gain v AF Err v PRatio.png

[curt@injected]

If you aren't using VCM Suite 3.7 already, download and install the latest beta. There is a table in beta under Engine -> Airflow -> Electronic Throttle -> Proportional called "Proportional Gain vs Throttle Airflow Error vs PRatio" (Table: 5999 ... See picture below). I was having the same throttle surging problem on my 2015 RAM 1500 with a Magnuson, set this table to 1.00 across the board and the issue went away.

Prop Gain v AF Err v PRatio.png

This. Had to do the same thing on one recently

[Ditosmotors]

I'm still on the latest 3.6 offering. I'll down load the 3.7 and get that customer back in here so I can give these ideas a try.

[[email protected]]

If you aren't using VCM Suite 3.7 already, download and install the latest beta. There is a table in beta under Engine -> Airflow -> Electronic Throttle -> Proportional called "Proportional Gain vs Throttle Airflow Error vs PRatio" (Table: 5999 ... See picture below). I was having the same throttle surging problem on my 2015 RAM 1500 with a Magnuson, set this table to 1.00 across the board and the issue went away.

Prop Gain v AF Err v PRatio.png

This is most likely your fix. Drove me crazy until this was added.

[Ditosmotors]

Thank you, that table took care of it.

[orrwhat]

If you aren't using VCM Suite 3.7 already, download and install the latest beta. There is a table in beta under Engine -> Airflow -> Electronic Throttle -> Proportional called "Proportional Gain vs Throttle Airflow Error vs PRatio" (Table: 5999 ... See picture below). I was having the same throttle surging problem on my 2015 RAM 1500 with a Magnuson, set this table to 1.00 across the board and the issue went away.

Prop Gain v AF Err v PRatio.png

Where is this table on the 4.0?Screenshot (36).png

[Jay@HAP]

Where is this table on the 4.0?Screenshot (36).png

I've seen a few OS that didn't have it. I don't if it's not actually there or if it just needs to be added.

[[email protected]]

could this be different for a 2018+ ecu? i have this on a 19 car with a whipple.
nothing including a lot of throttle and airflow stuff hemituna recommends doing is getting rid of it.
any suggestions are welcome.

[Hemituna]

Put table 14064 back to stock numbers.
Raise up table 39020 to allow more airflow.

[[email protected]]

how do i search by table number? not finding these in airflow section or torque mgmt.
have throttle steady now, it's only spark going nuts.

[[email protected]]

i do wish hpt wouldn't put important tables like those in diagnostic section. took forever to find them.
it's the same unfortunately. i really thought that would do it.

[wadejesu]

If you use edit function then type table number in text box, it will take you straight to the table.

[[email protected]]

ok, edit, then navigator and you can type in the table number. will not forget.
thank you.
hope to hear from ht or anyone else soon.
thanks

[Hemituna]

You might wanna take a look in the trans file and see what the limits are there...

[[email protected]]

a limit for part throttle? that's not in the tcu. tcu has 700+ nm limits and we're not making that, at least not according to ecu reported torque.
so i did what you originally suggested and lowered airflow tables. chose to lower 2v and below by 20%. your 2015 file from another post lowered them a great deal and the car didn't like those values.
i also only changed the 3 airflow tables, nothing in DD.
good news bad news. it worked, most of the time.
first go through the gear is great. no problems. this is around 1:15s in the log.
next try is at 2:18s and lighter throttle but then get on it enough in 5th get boost and still doing good.
next is 3:10s, lightly again, but get on it sooner. as soon as 3rd hits, give it over a volt of pedal and it goes right into the sawtooth. stays that way even through 4th and 5th gears.
go real light again at 4:15, no boost, does good.
then at 4:36, it's in 4th gear, low speed, i get on it enough it goes to 3rd and soon as catches 3rd and boost to 110kpa, does it again.
the only thing i can see in this is that it only does it when it's in slight boost. but interesting thing is there's on/off with this one. even though it's 2-3psi of boost, it's very smooth.
where to go next? still thinking this newer ecu thing. did 2015 jeep grand cherokee with built 427 and this same blower with a 3.0 pulley on 1000cc injectors and flex fuel and it never did any of this.
more airflow table work? DD tables?
thanks everyone for the help so far. hoping for more to come. this is making things no fun.

[Hemituna]

I'd look at your cam timing also as blowers dont usually like the stock numbers much.
You have a heap of STKR which is coming from somewhere so check knock sensor voltages, thresholds etc.
If it is not knock then it may be another limit somewhere pulling the timing.
May be that some of the later models have an extra trans table (max available engine tq 30262) and with blower you are bumping into this.
Get HPt to add this table if you cant find anything else causing it.

[[email protected]]

my experience is all engines love cam advance low and taper to zero towards redline. zero being what would be a cam that isn't designed for variable cam timing.
these cam tables are bonkers. the normal table is all 93 in the entire driving range. that's nearly full retard right? how can that be good? emissions?
do you have suggestions for numbers on the cam? i put in your 2015 file stuff and didn't drive nice. swear they've done different stuff new ecus.
could be hpt doesn't have all we need yet.
spent a lot of time with it today (had to get gas) and i have the timing fixed. it was the fucking NN.
it's a stock cam so i left it enabled as it drives like shit as usual with it disabled even when i spend time trying to perfect the ve table.
look at pr ratio table max in nn tab. was 1.2. i put to 2.0 letting it use it's "brains" in boost and was massively worse. couldn't drive the car once it went to boost. put it to .7 and magic. never again the timing chainsaw. also moved ve max to .7
next is what you're saying. there's huge kr everywhere below 2000. i can't find where its getting its timing. i have part throttle 1800rpm 1.3pr at -3 and it's showing 9 in the log with -6 kr. even mbt is close to that. iat is really high and i checked and i/c pump is working, can see pump moving water. no idea why iat so high. moved temp bias down to do even more retard for temp to help with this but does timing more than i can find no matter what.
i'm really at a loss. NN maybe? anytime i turn it off it just runs like shit. you think 18+ ecu is more dependent on it? you know gm is using it now too? this is probably Q for hpt more than us but wouldn't be surprised. these ecus are every bit as smart as your laptop.
what i'm left with is car drives ok now, but shifts gears way too fast and then holds them. runs 110-130 kpa 1500-2500 rpm closed loop with "why that spark".
i'll look at demon trans tables and ask customer pay license trans and at least try those tables. even if airflow is different, this is output shaft speed making gear changes, not airflow, all the tables are shaft speed. but have to think demon tables wouldn't make it lug like this.
here's current file.