I have a is38 full bolt on APR 93Oct, has everything you can imagine. Only thing is im on stock Diverter valve (which is supposed to be very good still), but i have the new is38 from the new R's with the new diverter valve assembly for only about 9k miles... I did a dyno run yesteday and only put 330 down which is completely off. I have the p3 guage and my tuner saw that my boost at around 5400 was going down to 18psi.... On the street at around that, im making about 23 torward 5500-6000 RPM. I peak at about 30-31. Based on the dyno curve you could see the is38 going up and up and up past 370whp but dropped at 5400 like said. We think it could be the PCV... What do you think? The car feels fine on the road but I dont know what the boost is supposed to hold at, or if its supposed to drop that low. What do you think?