Early MGF Trophy with Air Filter Valve - where is the vacuum drawn from.

For those with the first trophy's (MGF, not MGTF), they had an air filter valve (connected to one of the two air filter hoses) which was operated by a direct vacuum link. Could anyone with one of these early trophies (Vin no from YD525704 to YD530688) please tell me where the vacuum is drawn from? There are several possible sources but I want to confirm EXACTLY from which hose the vacuum is drawn from.

A later Trophy has a system with an exhaust valve operated by the MEMS 3 via a solenoid, vacuum reservoir etc. I am not talking about this version.

Many thanks.

I have no idea but what was the purpose of this valve?

James

It was supposed to reduce the drive-by noise which would have been a problem with the regulators on the Trophy. What happened was that the early Trophy (Vin nos from YD525704 to YD530688) was fitted with a standard exhaust at the factory (to strictly meet regs), shipped to the dealers who then fitted the Trophy exhaust plus the vacuum activated air filter box valve. Fairly shortly after with the MEMS 3, they fitted a more complex ECU driven vacuum system with the exhaust flap.