popping in exhaust at high RPMs the higher the boost the worse it is

[myblack98gst]

9:1 compression
FP2X cams
Magnus intake manifold
3" gm maf
to4e 50 trim
ramhorn manifold
3" turbo back
denso 660cc injectors
walbro 255hp fuel pump
3/8" fuel line from pump to rail adjustable FPR set at 40psi no vacuum.
bpr7es plugs
MSD wires
running 100LL fuel


more mods but inconsequential

I have been having issues every since the intake manifold install of it going lean up top 6k+ so I re-did all the fuel system with bigger line it made it richer for sure but it still leans out.


the MAF translator is set for 660cc on the global knob the others are all zeroed out.
the AFC NEO is like -35% till 5500 then it go to -13% till redline

this STILL maxes out the AFR gauge at 10.0 until 6000 then it hits 10.8 -11.3 the higher the boost the leaner it goes. and when it starts to lean it is popping out the exhaust 25psi @6k sounds like gun shots going off almost like rich popping. 20psi only does it real high rpm like 7k up.


I need to get the fuel pressure gauge mounted in the cad so I can verify it holds good but I would assume so.

the coils are now mounted off the strut tower. and control module off one of the rear T-belt cover bolts.



at this point I am lost.

could it be a weak coil pack?
blowing out spark?
maxing 660cc's
translator screwed up?

 

[94Jettameowpsst]

Sounds like your maxing out the injectors. im running into a similar problem but the one thing we both have in common is we lose all tuning capabilities at some point high up in the rpm range. Dont you have some way to log your duty cycle?

 

[perley03]

According to the DSM Tuning Sheet (Excel format) even at 100% VE (which you will be running up around 120% with the SMIM and cams) you are maxing out those 660's. In order to maintain an 11:1 afr, at 25psi you will be seeing ~42 lb/min, which in turn will require at least 880cc injectors to keep your IDC down near 80%. All of this is calculated at 37.5 psi fuel pressure.