| On my 931, there's a wastegate AND a "pop-off" valve. The wastegate lets
exhaust bypass the turbo when it reaches full boost. The "pop-off" valve is on the intake side, and it's function is to route boost back to the inlet side of the compressor when the throttle is closed so the turbo will stay spooled up and ready for the next time you open the throttle. Any questions? :) Tom 78 Audi Fox GTI 79 Rocco 80 Rocco (future SOLO car) 81 Rocco S (parts car) 81 Porsche 924 Turbo (blown turbo) 82 Rabbit Pickup 85 Audi Coupe GT 86 Rocco 8 V (daily driver, future 16 V) 87 16 V Rocco (organ donor) |