Part Throttle Surge, Desperate for help

[zkonmando]

Hey guys, I got the car running great on the dyno. It made good power and sounds good. However the part throttle has a weird surge that I can't get to go away after hours of making revisions and reading the forums. I am also having a pretty harsh transition to WOT. I need to get this thing done pretty quick so it can go home. I am willing to pay if you will teach me and not just send me a revision. Knowledge is learned through many hours and time is valuable. The car has an unknown cam and built bottom end with more compression than stock but don't know exact number. Any help is appreciated. Thanks guys.

6.4 swap 2012 challenger w/ unknown cam and forged pistons and rods, higher than stock compression on 93

[zkonmando]

Tunes PT1

[zkonmando]

Tunes PT2

[zkonmando]

Tunes PT3

[zkonmando]

Again any help is appreciated. Thanks for the help.

[N2speed]

can you explain the surge any better? Why is the idle set so high? is it bucking with your foot on the break while in drive?

[zkonmando]

can you explain the surge any better? Why is the idle set so high? is it bucking with your foot on the break while in drive?

Idle is set to 675 I didn't think that is very high. The surge is from about 800 to 1200 rpm with that really light throttle applied. I found out that it does it in park and in gear. It bucks a little but its a stock converter.

[N2speed]

Looking at you log looks like it is hitting 1000+ RPMs at Idle should be around 850 IN Drive and 750ish at Idle in Park. Try that. If the cam is to big you could be bouncing off the converter. Try unlocking it and see if it helps

[zkonmando]

I can try raising the idle but idle is stable. Just did another log Log 27.hpl with this tune Write 1, rolling idle speed increased.hpt I made last night before I realized that it did the same surge in park and neutral. The surge occurs almost everytime at .65 pedal volts.

[N2speed]

Does this have a supercharger?

[FstdodgeKY]

Try decreasing to tb airflow table in that area. Start with small range first. Multiply by .85. Could also be in power percent tables as well. Do you have wideband?? Could be fueling. To kean or fat can cause same issue

[zkonmando]

No supercharger, it's NA. I have tried the TB airflow table many times. How does the correlation between the TB airflow table and the small and large range tables work? Do they have to be inverse of each other? Also when you say multiply by .85 do you mean to the axis (airflow) or to the voltages? Whenever I have tried the TB airflow table I always did the inverse in excel and pasted that to the small and large range tables.

[FstdodgeKY]

There are a few really good threads on here about how these tables work. In simple terms the lower the number makes the pcm think its flowing less air so it open the tb more. Also if you go bigger it open less.

The small range is to have a better resolution for small throttle inputs. Kinda like when you cruising around and pulling out into traffic type situations
I Use this table mostly for fine tuning TB for PT tuning.

The large is for making bigger throttle changes like when you go to pass some one at highway speeds etc.

The main tb table is for airflow calculations that help the pcm know exactly how much air is going into motor at any given range according to the axis of the table.
This table i have found helps control throttle hanging and or lagging pedal feel.

This is only how I have interpret this information and I could be completely wrong, again ther are very good threads on this information. Do a Google search for dodge Throttle body hp tuners and it should pop up some older threads

Let's not forget fueling. A lean or rich condition can cause this same effect of stumbling at a certain spot in the tune. I have not looked at you log/tune. Also changing airflow tables will cause fuleing to be changed. Due to airflow.

A large cam will need more airflow at idle and just off idle as well as fueling. Also if the converter is to small then its hard to control the off idle conditions due to the converter surging and trying to engage/lockup right off idle.

[zkonmando]

There are a few really good threads on here about how these tables work. In simple terms the lower the number makes the pcm think its flowing less air so it open the tb more. Also if you go bigger it open less.

The small range is to have a better resolution for small throttle inputs. Kinda like when you cruising around and pulling out into traffic type situations
I Use this table mostly for fine tuning TB for PT tuning.

The large is for making bigger throttle changes like when you go to pass some one at highway speeds etc.

The main tb table is for airflow calculations that help the pcm know exactly how much air is going into motor at any given range according to the axis of the table.
This table i have found helps control throttle hanging and or lagging pedal feel.

This is only how I have interpret this information and I could be completely wrong, again ther are very good threads on this information. Do a Google search for dodge Throttle body hp tuners and it should pop up some older threads

Let's not forget fueling. A lean or rich condition can cause this same effect of stumbling at a certain spot in the tune. I have not looked at you log/tune. Also changing airflow tables will cause fuleing to be changed. Due to airflow.

A large cam will need more airflow at idle and just off idle as well as fueling. Also if the converter is to small then its hard to control the off idle conditions due to the converter surging and trying to engage/lockup right off idle.

I've done a lot of reading on the older post and have trouble wrapping my head around it all. From this it sounds like the "range" tables are not required to be inverse of the TB airflow table. I have heard mixed info on that though.

It seems like just changing the small range table may be my fix. Possibly pasting that area to the large range but leaving tb airflow alone?

[FstdodgeKY]

Yes. I try to keep the tables close but don't have to be the inverse of each other. Just experiment with it and see what it likes.

[HaasExp]

Just going back to basics: have you tried a throttle relearn and reset all the adaptives?

[zkonmando]

Just going back to basics: have you tried a throttle relearn and reset all the adaptives?

Have not tried a throttle relearn lately but have in the past. I reset adaptives on the engine side every write.

[FstdodgeKY]

Is NN on/off? Also have you changed any of the driver demand tables??

[zkonmando]

Is NN on/off? Also have you changed any of the driver demand tables??

I'm doing fueling by ve as the cam phaser is locked out. I have not messed with any driver demand tables as I don't know where to start with them

[zkonmando]

After an extreme amount of writes, I am about ready to give up on the car. I cannot get the surge 100% gone and now there's a huge throttle hang at 3500 and any rev to 2500 or more takes forever to return. If anyone has any advice I'd love to hear it because I have read every forum post that I can find about tuning the throttle and I either don't understand it or it just isn't working. My offer for paying someone to teach me is still open. I can share logs and tunes but they're all just modifying either the tb air, small range, and/or the large range tables. I've gone up in all. I've gone down in all. Some progress was made but it's so negligible for the amount of time that has been put into this car and now I have discovered the throttle hang and I have no clue if it has always been there or if something I have done recently has done it.