I was on the freeway last night and noticed that my car was surging in 5th from 80km/h as i was trying to gain speed. It would hit 5psi and bounce up and down to 2psi while fluttering. Could it be because i was suppose to drop a gear before giving it some? I tested it on both uphill and flat road, but still had the same problem. I'm running vortex 98, turbo back, wolf 3d, 18psi t3/t4 hiflow, denso pump, nismo 555cc, greddy type-s plumback
cheers.