Guys,
Following this thread : https://forum.hptuners.com/showthrea...efore-4600-rpm
I removed the TSP VVT3 Cam and installed a GPI Stage 3 cam and performance Morel 4708 Lifters ($750 the set !). I paired them with 7.750 comp cam pushrods, which was the correct lenght after using the comp cam push rod measuring tool (7.700 + 0.050 of preload). Also did a complete engine rebuild since the engine was out.
This cam is a little less aggressive on the intake but more on the exhaust, with a 112LSA instead of 116LSA
No matter what I have EXACTLY the same issue than with the TSP VVT3 with the GPI Stage 3 !!!
Engine makes decent torque down low until 3500 rpm, then fall on its face for the next 1000rpm....Despite consistent timing, no torque management, no knock retard etc (exactly has the TSP). I tried again Ben Charles program or mine, same in both case. Airmass is falling or not climbing in this range. Keep in mind my 3000FT elevation
On top of that the 112 LSA makes the idle a lot harder to stabilize, I'm struggling a lot of that. PCM keeps giving me P300 Random misfire, even at 1000 rpm idle I get like 10-15 misfires per cylinder. I'm really bummed... I managed to get it better in very low load transition by decreasing the external load torque value, but now my idle surges...Also since the idle is shitty the MAF calibration in this area is difficult to obtain in those low frequencies (2400-2700 and 2800hz)...
I precise right now I'm on MAF only, I had a comment from Hassan that it was the transition from Dynamic to MAF, nope, not that Dynamic is disabled...
I precise stock cam was dot to dot on cam timing, Did the same for the TSP and the GPI. Jumping 1 tooth would be 8 degree, I can't see how it could be possible both the TSP and the GPI have exactly the same behavior if it was a timing issue. If stock cam was dot to dot, if only the TSP was having the issue it could have been a ground issue. On 2 different cam I don't see that possible.
I ordered a stock ported IM to see if the issue could come from my used MSD IM (bought it used). With the TSP I put a 100% stock IM from my Camaro and it reduced the issue, without making it disapear though.
See some logs
Prog Alex 062020.hptAlex 062020.hplpull2 14062020.hpl
I'm lost and pissed...
Thanks