You Probably Don't Tune Very Many Old Turbo Hemis But I Thought I'd Ask You Anyway. I Have A 5.7 Hemi Turboed On A NGC4 PCM (2007-2010 Era). I Had The Same Problem On The Older NGC3 As Well. What It Does Is You Will Hold The Accelerator Pedal At A Fixed Point Holding A Steady Speed (Above 50mph usualy). When You Start Climbing A Hill The Throttle Body Opens Up Despite Not Changing Pedal Position. The Result Is A Massive Jump In Boost Pressure And The Thing Takes Off Like It's Racing lol. It's Related To Boost Pressure / Air Mass Going Into Engine. It Does Not Happen At A Specific Engine Load Or RPM... If This Makes Sense It Happens A Certain Air Mass Acceleration. So It Occurs Only A Certain Boost Spool Rate. What It Also Does Occasionally Is If You Are Going Up A Hill It Will "Runaway". The Throttle Stays Open At About 30% According The HPTuners Even With Foot Off Accelerator Pedal. It Will Stay Running Away Until You Reach The Top Of Hill And Grade /Load Is Gone. My Tuner Has Messed With This Numerous Times With Minor Fixed To It Here And There. I've Also Spent Over 40 Hours Total Street Tuning It And What I've Found Helped It The Most Was Part Throttle Spark And WOT Spark Tables. Basically Pulling A Lot Of Timing Out In Areas Where It Knocks Alot. My Tuner Thought It Was False Knock But It Was Indeed Knocking Over 12Degrees In Areas. The Issue Is Still Present And I've Got The Spark Tables Dialed In Perfect But There's Just Something I'm Missing To Completely Get Rid Of The Runaway / Throttle Blip. My Tuner Theory Is Basically This " The PCM Sees Air Coming In And It Thinks It Needs To Use Up That Air By Opening The Throttle". The Throttle Never Closes Abruptly Either. The PCM Likes To Try And "Decay" The Boost / Air Flowing Into The Engine Slowly. The Turbo Never Surges And There Is About Half A Second Delay When You Let Off The Gas When Under Boost Before The Vehicle Stops Accelerating. No One Has Any Info On This And I've Been Diving Deep Into This. There Are No Other Turbo Hemis Running A NGC3 Or NGC4. I'm Not Even Sure How Many JTEC Hemis Are Running A Turbo Either. Superchargers Yes But Turbos Are Completely Different Animals With Chrysler Hemi PCMs.
What I think is happening in my opinion is that when you start to climb the hill the load increases, increased load draws in more air forcing the throttle open under boost. I recommend changing tables related to torque and air flow together. Mainly the pedal follower tables.
Yes!!! More hemi stuff please!!
I got my 6.4 swapped duster runnin good from watchin your hemi playlist videos!! Thank you
I’m glad to hear that man!
You Probably Don't Tune Very Many Old Turbo Hemis But I Thought I'd Ask You Anyway.
I Have A 5.7 Hemi Turboed On A NGC4 PCM (2007-2010 Era). I Had The Same Problem On The Older NGC3 As Well.
What It Does Is You Will Hold The Accelerator Pedal At A Fixed Point Holding A Steady Speed (Above 50mph usualy). When You Start Climbing A Hill The Throttle Body Opens Up Despite Not Changing Pedal Position. The Result Is A Massive Jump In Boost Pressure And The Thing Takes Off Like It's Racing lol.
It's Related To Boost Pressure / Air Mass Going Into Engine. It Does Not Happen At A Specific Engine Load Or RPM... If This Makes Sense It Happens A Certain Air Mass Acceleration. So It Occurs Only A Certain Boost Spool Rate.
What It Also Does Occasionally Is If You Are Going Up A Hill It Will "Runaway". The Throttle Stays Open At About 30% According The HPTuners Even With Foot Off Accelerator Pedal. It Will Stay Running Away Until You Reach The Top Of Hill And Grade /Load Is Gone.
My Tuner Has Messed With This Numerous Times With Minor Fixed To It Here And There.
I've Also Spent Over 40 Hours Total Street Tuning It And What I've Found Helped It The Most Was Part Throttle Spark And WOT Spark Tables. Basically Pulling A Lot Of Timing Out In Areas Where It Knocks Alot. My Tuner Thought It Was False Knock But It Was Indeed Knocking Over 12Degrees In Areas.
The Issue Is Still Present And I've Got The Spark Tables Dialed In Perfect But There's Just Something I'm Missing To Completely Get Rid Of The Runaway / Throttle Blip.
My Tuner Theory Is Basically This " The PCM Sees Air Coming In And It Thinks It Needs To Use Up That Air By Opening The Throttle".
The Throttle Never Closes Abruptly Either. The PCM Likes To Try And "Decay" The Boost / Air Flowing Into The Engine Slowly. The Turbo Never Surges And There Is About Half A Second Delay When You Let Off The Gas When Under Boost Before The Vehicle Stops Accelerating.
No One Has Any Info On This And I've Been Diving Deep Into This. There Are No Other Turbo Hemis Running A NGC3 Or NGC4. I'm Not Even Sure How Many JTEC Hemis Are Running A Turbo Either.
Superchargers Yes But Turbos Are Completely Different Animals With Chrysler Hemi PCMs.
What I think is happening in my opinion is that when you start to climb the hill the load increases, increased load draws in more air forcing the throttle open under boost. I recommend changing tables related to torque and air flow together. Mainly the pedal follower tables.
@@Recklessmotorsports Awesome I'll Start Playing Around In Those Areas And See If I Make Any Progress On This.
i need you a tune for my 6.1 300 lol
Still ain’t done lol
@@Recklessmotorsports waiting on you to come back to kansas haha