On Boost Breakdown

[ttlctrl]

ive got an R32 gtst rb20det i recently threw a dump pipe on and now i have a misfire at 4000rpm onwards to 5000, 5500 its flat all over the revrange as it is also. it has recently been serviced plugs filters oil ive swaped the coils out and the igniter but still its misses ive been told to gap my plugs its all standard i dont understand why it should need this.???? any help would be awsum.

[limpus]

Well...the coils might not be firing at optimum and hence spark would still be weaker...with the dump pipe and any other mods your boost levels would have come up slightly too...with an issue like yours...8 out of 10 times the culprit would be plugs with too big a gap...try something with a gap of about 0.8...for a rb20...i'd run bcpr6es or bcpr6e plugs...they are already pregapped to 0.8...give it a go...