Popping at 20 psi.

[8scbuick]

I run a Twin Turbo car with 2 T70 turbos.This all started in the spring as a mild popping under boost and high(6k rpm and higher)
rpm.As time progressed it was getting worse.The only way to get rid of the popping was to turn the boost down to 16-17 psi.
Changed wires,coil pack,module,still it stayed.
What I have noticed was the Felpro keeps taking fuel out.
My A/F ratio is at 11.2.But it just keeps taking it out.
What I`m thinking is valve springs.I have about 3 1/2 years on these springs.The motor has a PTE big roller in it ,Lift is about 680 lift.
Taking ideas now.
Thanks
Tony

 

[EightSecV6]

Springs are shot, need a bunch of pressure on the intake on a S2 head due to the valve size and the boost assisting it to open.It is taking fuel out because the popping (missing) is putting raw fuel in the exh. and the O2 sensor reads this as rich.