On rally cars they do not use blow off valves because they do not want to loose any throttle responce.
They run a lot of boost & the compressor is surging during on & off throttle position constantly.
The pressurized air has to go somewhere when the throttle is closed,well it does go somewhere, it goes backwards through the turbochager like my Syclone did before I installed a BOV.
I think Douglas' turbo is a 80 MM compressor wheel, is that considered big?
MBHD
