irl, centrifugal and twin screw supercharger designs compress the boosted air even at idle, and as such typically have a blowoff valve or waste gate to close or open at certain times to avoid detonation or other going boom related things. i've tried adding both a wastegate and bov to a centrifugal system i'm working on but it doesnt do anything. beamng appears to only allow these on turbo setups. is there a workaround?
no. i've tried adding the bov/wastegate tag to a supercharger and nothing happened. i asked agenty who's in better contact with the devs why that is, and he said its not possible because the turbo and supercharger systems are completely separate. as for if it will ever be updated, i asked pretty please very nicely. so probably not.
There's no need to install a bov or wastegate on a supercharged engine. For a turbocharged engine, the BOV is located between the compressor and the throttle valve, since the throttle valve is located downstream of the compressor, closing the throttle cause the compressed air nowhere to go, hence the need of a BOV. for a supercharged vehicle, the throttle valve is located upstream of the compressor, closing the throttle reduces the air intake of the supercharger and that's it.
this is true for normal roots blowers only since they dont compress the air going in. for twin screw or centrifugal setups though blowoff valves are an absolute necessity to release pressure when off the gas, just like a turbo.