if u mean the switching point id leave it standard ifaik the mainifold pulse tuning has nothing to do with the engine internals as for power increase it gives a bloody huge lump of torque 3-4k rpm then it switches and drops off about 20 lb ft acording to the dodgy/dubious rr session i did it gained 80 lb ft at 3500 rpm!!!! that put peak torque upto 235 lb ft @ 3500 rpm i think its crap but its probably around 215 lb ft which makes + 60 lb ft then after the switching point (4k rpm) it dropped to about 205-210 lb ft which an alledged gain of 20 lb ft which again is probably crap i cant wait for