Compiling common Gen5 tune changes for Cam, Headers, Thermostat, and Catless

[antob94]

would these changes for the fuel pump work for an l83 or only for l86?
currently have a 2014 l83 with a btr stage 2 cam with a 14% fuel lobe and 4 degree phaser
and having bucking issues when gaining speed on speed density

[GHuggins]

You should be fine with just increasing the axis... It shouldn't be bucking.

[GapRider]

I?m glad GH responded, he knows WAY more than me, but your question made me think of two things.
One, you should be able to log requested and actual fuel rail pressure, they should stay really close, all the time
Two, you might be able to zero in on the bucking more by logging spark and Torque Management Advance. In my car (Cammotion Titan 3 cam, really close to BTR stage 2), I noticed bucking at really light throttle and low rpm WHEN Torque Management Advance jumps in and causes back and forth changes in spark. This may not be where you?re seeing bucking but I?m throwing it out there

[antob94]

Thanks y'all
I'm still trying to learn how to tune but
I adjusted the fuel edge angle axis and kept adjusting my sd tune where it finally got rid of the bucking
now I'm just getting issues when accelerating at high rpms
Would I just need to keep adjusting sd or am I missing something?
my sierra 7-4 back to sd 6.hpt
7-6 morning log.hpl

[jmiller1119]

Im curious as well, i might go up a couple numbers

[cmitchell17a]

What RPM is the bucking occurring at? With that cam I would think you would be maybe wasting effort trying to trial and error things to get the bucking to go away if its below 1000 or 900 or so RPMs, I would think you wouldn't be able to get combustion stability even slightly good enough for it not to do weird things like that.

Is the bucking more of a feels like it has no power so you give it more throttle and nothing happens so you go some more, then all of the sudden it goes, so then you try to let off then its too much and you try to give it more and then it starts bucking back and forth like the whole car structure and throttle spring is in resonance? Or is this just bucking at rolling idle with no throttle application? Also is it on the stock torque converter?

I would think anytime you see torque management advance at anything other than zero, it would be because something is wrong with your torque model or either your airflow model is wrong and causing issues with your torque model? But maybe I am wrong? I really don't know.

When I get this, its very distinctive from the low rpm cam induced, combustion instability bucking. Its at a higher rpm around 2000 rpms, and you can see torque management advance make what looks like a square waveform with zero signs of a consistent frequency and very random.

[Jer4251]

Good stuff. Got my truck running pretty solid atm.