Originally Posted by Stealth69
They only sound off on lift off, they don't do anything on gear change on this car
Gearchange is so quick that there's never a real moment where the throttles close and a BOV is required.
It's also the reason why your MAF tuned GTR doesnt drive like crap using VTA BOVS.
Personally I think you're risking bore wash, fuel into oil contamination, crapped up spark plugs when to VTA on a MAF tune.
Go SD if you want VTA with no risk.
Back to OP question... you're risking a slight increase in rich running when off throttle as the standard tuning method is MAF and the ECU has already injected the correct amount of fuel for the metered air, so when it's blown off you run rich.