OK, I belive some events spread out over today have caused a problem with my car (1991 9000 Turbo). I had been running it with top tube of the BPC valve removed (called the wastegate line??) since my BPC valve is stuck underboosting. I know it was a stupid thing to do but I assumed I could just keep an eye on the boost guage and it'd be fine until my boost controller arrived. Well today during acceleration from a light, I let the boost guage go up to right before the checkered area of the bar and eased off the gas. Right as I did that, there was a loud pop and a hissing noise. The car managed to creep along to an area where I could stop it, but would barely idle when I got it there. I checked around for vacuum leaks and found my usual suspect, the tube right below the begining of the throttle body. I reattached it (and the wastegate line) and started up the car. It idled horribly for about 30 seconds (bouncing between 250 and 750 then evened out (usual 900-1000 rpm) as if nothing was wrong. The car drove just as normal on the way back exept for an odor I noticed only at a stop. I got it home and looked at the engine. The pipe directly behind the turbo was glowing red hot (turbine?). I let it cool down for the next 3 hours. I then took it on a short trip to see if the problem had fixed itself. This time only the corner of the pipe closest to the exhaust manifold was slightly glowing. During this trip I noticed no strange noises or smells, just that it idled a little rougly for the first 15 seconds after being started. Any suggestions or advice would be very much appreciated.