2021 Silverado 6.2 PD blown 100% TPS spikes

[xsesiv]

Experiencing throttle spikes on a 2021 Silverado 6.2 with the E90 ECM and a Harrop 2650 PD blower. Mild throttle pedal movement in part throttle results in 100% TPS spikes.
Otherwise TPS tracks throttle pedal movement well during slow or instant pedal movements. Significantly increasing Virtual Torque in the spike areas reduces the TPS spikes somewhat but causes other issues like hard gear shifts and TPS surging at light throttle cruising. Tried reducing torque values in DD but didn't help.

I've tuned the MAF and VVE with NN and they're close, MAP and airmass sides of Virtual Torque seem balanced, have tried increasing MAP VT only, then airmass, tried several different DD maps with the Driver Demand Editor. Have installed a SCIAP sensor.

I think it's Torque Management causing the TPS spikes but just can't nail down an acceptable solution as extrapolate coefficients messes the off boost areas up when I increase torque in the boost areas too much. Unless there's a background table I can't see.

Any help would be much appreciated.

2021 Silverado 6.2
Harrop 2650 blower at ~9psi
LT4 HPFP & injectors
1 7/8" headers, hi flow cats, dual 3"
K&N intake
93 octane
DSX IAT & baro breakout box from digital MAF so I have true manifold air temp using LT4 TMAP sensor
SCIAP sensor wired in to E90 ECM using 1 bar GM MAP sensor

2021 Silverado 6.2 Harrop 2650.hpt
2021 Silverado 6.2 Harrop 2650.hpl

[will_974]

With a SCIAP setup, you do want to keep the barometer in the MAF air box. It is needed to keep the throttle blade pressure drop calculation correct.
You also will want to have both the IAT in the MAF, and the IAT post roots. This is needed for more air density calculations.

Next up. you'll want to request the Throttle Area vs position table from support.
(I used to offer these tables, but Hptuner put in the work to find them so i now send people to support to get it)
This table on the Truck OS's seems to have a much faster ramp, and in my experience causes the throttle to snap open.

I do see that you have disabled the airflow checks. This may mask potential issues with sensor wiring.
When I start offering services again, I would be happy to adjust the SCIAP performance table and the Barometer smoothing factor which can fix these error and allow those tests to be enabled.

Next up looking at the driver demand table, It is in axle torque. Which means you will need the commanded power table to convert from axle torque to engine torque.
HPT has located this in the past but it is not one they have released in many OS.
As power increases, Bumping only axle torque will lead to inconsistent throttle control.

Hope This helps.

[xsesiv]

Thanks for your valuable knowledge Will, I've requested HP Tuners Support to add the "Throttle Position vs Area" table. Will provide an update once I've tried it.

The DSX breakout box has an inbuilt barometer and the box is located in my air box pre air filter. The LIN based MAF still provides IAT, I've wired the Manifold Air Temp sensor on the LT4 TMAP post rotors to the DSX breakout box so the ECM gets both IAT and MAT.

I'll also see if Support can add the Commanded Power table, I believe that's ECM 33008 "Driver Demand Engine Torque".

[xsesiv]

HP Tuners Support in the latest Beta has added the following tables:

ECM 26414 - Throttle Position vs Area (Throttle position to throttle effective area correlation)
ECM 33008 - Driver Demand Engine Torque (Current demanded engine torque from the driver)
ECM 32872 - Supercharger Linear Flow Constant (Constant of linear flow function of supercharger speed and pressure ratio)
ECM 32873 - Supercharger Revolutions to Volumetric Flow Coefficient (Coefficient of supercharger speed to volumetric flow in the flow model)
ECM 32874 - Supercharger Flow to Pressure Ratio Constant (Coefficient of linear flow function of supercharger speed and pressure ratio)

Will report back once I've tried them. I'll start with using a Camaro LT4 Throttle Position vs Area table.

[will_974]

Perfect!
Im glad HPT can now locate all those tables in the E90/E99 as well.
That lets me spend bandwidth on new avenues!

The First 2 are the most important,
Throttle table will help with snap opening by adjusting the positions which result in higher throttle position
The Engine torque or commanded power table will help by requesting more engine torque at different requested axle torque

The blower calibration values can help remedy the Barometer error (P2227) but I haven't found a solid use for them otherwise.

Once I re-open my store, I can help get the SCIAP Performance table to help remedy the P101 error that will happen as you move into boost.
I have not seen HPT locate this table as of current posting.

[MeanMike]

I'm still having a little bit of this same issue. A small throttle spike on acceleration. I can see the extra tables in your tune file, but not mine, so I've requested HP tuners add them for mine also. Hopefully we can figure this out. Mine isn't intolerable, but it would be nice to fix it.