cant boost over 5psi without terrible bogging...help please

[sluis05]

i have a r32 with a rb25det swap, just bought it and new to the import thing. if i have over 5 psi of boost it starts bogging really bad and it also will not rev past 5000-5500 rpm. i changed the spark plugs and gapped them to 1.1 mm, changed the blowoff valve and vented it to atmosphere.

[Nismo_line]

gapping is supposed to be .8mm regap and see if that helps

[amnash]

have you ever messed around with intake manifold or ic piping? i had a torn plenum/intake manifold gasket and had the same symptom you mentioned above. while the engines is running, start from intake and work your way back feeling for leaks.

[Skym]

Engine can start reving up and down (o2 sensor causing this) when there's a intake airleak on intake manifold to head joint, miss at idle.

Bog can mean knock maps which can pull ignition timing to 0 degrees with foot to floor, dump more fuel in, drop boost level, etc. The safety revlimiter is set at around 5000rpm. Faulty knock sensor, knock, speedo at 0km/h are few that could cause the safety revlimiter to engage. I agree about trying to gap sparkplugs, use correct heatrange. Try this first to see if it fixes the problem. I think it should be PFR7A for R33 RB25DET (factory is PFR6A) with 0.8mm gap.

[Bruizer]

Everyone gaps differently. I used 1mm on OEM everything, then went to .8with 300hp now I use 1.1mm gap but would suggest .8mm if you have stock coils or no amplifier. Sounds like a plug issue. Have you done a compression test which doing plugs? curious.