Today I was on the highway in 5th at about 2000rpm, and I hit the gas to pass a slow car, and the revs climbed a lot faster than usual, and I noticed that I wasn't going any faster. First thought is that I need a new clutch. Is there any other possibility that would produce this result (only happens when the boost gets over ~7psi and the revs over 2000 where it starts making power), and if so, is there anything I can do without taking the transmission off to keep it driveable much longer?