Magnuson Silverado throttle oscillation help

[smokeshow]

Yeah that is odd. However it wouldn't be the first time something was mislabeled, either in the scanner or the editor.

Cool to see people having success with this now though. I've brought it up in various conversations over the years and people usually assumed I was full of shit lol. Physics will get ya

fbd.jpg

[Alvin]

I have another thread going on about this.. If you want to check what I did to the edelbrock tune to enable the sensor.

Someone said to turn "supercharger fitted" on... I've had issues with that in Gen 4 stuff.

But like I said before.. it made a tremendous difference in driveablity. I just wish I saw what I expected in the scanner

[smokeshow]

I have another thread going on about this.. If you want to check what I did to the edelbrock tune to enable the sensor.

Someone said to turn "supercharger fitted" on... I've had issues with that in Gen 4 stuff.

But like I said before.. it made a tremendous difference in driveablity. I just wish I saw what I expected in the scanner

What sort of issues? It can make your torque management more aggressive, and the knobs to dial it back are rarely defined. But again it depends on the calibrations that you enable by flipping that bit. There's no legal requirement to populate those inactive cals with reasonable values, so there's no guarantee what you're enabling. User defined can help but may be more work than its worth. Long as the SCIAP fixes the boost transition...send it.

[Alvin]

What sort of issues? It can make your torque management more aggressive, and the knobs to dial it back are rarely defined. But again it depends on the calibrations that you enable by flipping that bit. There's no legal requirement to populate those inactive cals with reasonable values, so there's no guarantee what you're enabling. User defined can help but may be more work than its worth. Long as the SCIAP fixes the boost transition...send it.

If I remember right it picked up a big hesitation and also felt like it had the VVE bug. (huge spikes in GMVE IDC SPARK) This was GEN 4 LS type stuff. Both 2008 Trailblazer SS"s if I remember right. I feel like a Chevy SS gave me fits too.

[castorjames]

Today ill teSt another truck. it haS the Same iSSue, weird to drive becauSe of the throttle body (it haS magnuSon Sc). ill Share reSultS, hope thiS make the trick again.

[GPGTP]

did it have the problem? Or did it work?

[Ben Charles]

Just buttoned this up over the weekend. This is on a 2016 Suburban, L83 5.3L. SCIAP sensor is in and functioning as expected.

I can echo castorjames results. The addition of an SCIAP sensor and polishing the Driver Demand table has 110% solved my throttle oscillation and spike issues. Accelerator pedal and throttle position track each other spot-on in virtually all scenarios now.

This does require opening up the ECM connectors and removing/installing pins. Tedious, detailed work but fairly straightforward.

ECM Modifications
X1 Pin 4 (TIAP Sensor Signal) -> move to X2 Pin 45
X1 Pin 5 (TIAP Sensor 5V) -> move to X2 Pin 64
X1 Pin 4 -> add Pin 1 on SCIAP Sensor Signal
X1 Pin 5 -> add Pin 3 on SCIAP Sensor 5V
X1 Pin 20 -> add Pin 2 on SCIAP Sensor Gnd

This mirrors the LT4 ECM pinout. Probably didn't have to move the 5V power wires, but my OCD required me to move them over.

Update Pressure Sensor Type to SCIAP-TIAP in the tune.

Vapor Worx remote MAP sensor mount:
https://www.vaporworx.com/shop/produ...nting-bracket/

Used the stock L83 MAP sensor, GM 12644228.

Repoll for supported parameters in VCM Scanner, and you can add the Supercharger Inlet Pressure PID.

Wanted to question the pin outs here?
On the connector for the Sciap (simple 1 bar map)
Pin 1 should be 5volt reference
Pin 2 low reference/ground
Pin 3 map sensor signal

[GPGTP]

Wanted to question the pin outs here?
On the connector for the Sciap (simple 1 bar map)
Pin 1 should be 5volt reference
Pin 2 low reference/ground
Pin 3 map sensor signal

are you saying the listed pinouts are incorrect and what you have is the correct pin out? what vehicle did you do it on?

[Ben Charles]

are you saying the listed pinouts are incorrect and what you have is the correct pin out? what vehicle did you do it on?

Customer of mine installing on his 16 lt1 camaro with 2650 and not getting signal.. he mentioned this thread… I looked up the pins for the map and they differ from the above on the 5v reference and the signal (it’s backwards)..
I have a PD blower on my personal car and run the map setting as NA-Tiap and have no problems in or out of boost and I make 20psi on a 2.3

[Alvin]

Customer of mine installing on his 16 lt1 camaro with 2650 and not getting signal.. he mentioned this thread… I looked up the pins for the map and they differ from the above on the 5v reference and the signal (it’s backwards)..
I have a PD blower on my personal car and run the map setting as NA-Tiap and have no problems in or out of boost and I make 20psi on a 2.3

That's kind of the odd thing. I've had some go on with no issues at all. Some that were just untuneable without this. Really early on in the GEN 5 days we had a dealer installed magnacharger on a escalade that was so bad with magnachargers tune and I couldn't make it any better they took the thing back off. But I did plenty of them since then and most went perfectly.

I feel like the right thing to do is wire a SCIAP on a PD car just how VVE should be tuned on just about all applications even though some people get by fine without it.

I've checked the pinout personally a couple of times and its correct. I feel like we can probably get by by not swapping the GND and 5v references but.. at least this way its exactly how it should be.

[Ben Charles]

Thanks for the reply Alvin, been contemplating doing it on my own car just to see if I can make it any better.. if anything I can see how efficient the blower setup is with the SCIAP…

Customer may have something else going on? I’ll dig a little deeper. If I decide to Do the sensor I’ll chime in with my outcome

[Alvin]

Thanks for the reply Alvin, been contemplating doing it on my own car just to see if I can make it any better.. if anything I can see how efficient the blower setup is with the SCIAP…

Customer may have something else going on? I’ll dig a little deeper. If I decide to Do the sensor I’ll chime in with my outcome

I'm not completely sure of your issue.. But the first car I did this on.. I could see the voltage changing but the SCIAP pressure wasn't changing or something odd like that. It was a edelbrock supercharged C7. Even though it didn't appear to work as it should it made a tremendous difference in driveablity right away with no other tune changes. The other ones we have done work right away like a LT4 car.

Another thing I found is at this point we cannot change the BARO config.. (scalar/offset) AAP1-3 are not it. There is a separate scalar/offset someone has found and has added as a user defined parameter.. So having said that use one that works the same as the OEM baro. Typically 128.13 x -0.31

[will_974]

The Scalar and offset for the SCIAP sensor have been added to VCM suite
You may have to request them for your specific OS

[ECM] 4013 - Supercharger Inlet Air Pressure Sensor Linear:
[ECM] 4014 - Supercharger Inlet Air Pressure Sensor Offset: