Firstly, I'm not sure if this is the correct place for this query, so I apologise in advance.
Was driving my mates standard Polo GTi (minus TIP and filter) yesterday and noticed how vocal the induction was - including the recirc valve.
It opens quickly and you can hear it dump really well.
My 1.8t is the opposite. I've placed the recirc port pretty close to the filter (within 4 inches) and it's not that loud unless its got a lot of boost behind it. Furthermore, you can't really pump the pedal to get it to continually dump unless you're up at 3/4k.
The valve could well be original (now on 143k), so could be leaking, so I'm going to replace and see the difference.
But, is there a map that controls the shut speed of the throttle plate? When you snap your foot off the throttle, the boost gauge takes second to return to vacuum. Now, its either because the engine is still consuming the rest of the air once the plate is shut to produce vacuum, or the plate is slow to react.
Now, is the reaction of the plate caused by the internal spring - and not the motor, or?
Just thinking out loud here.
Thanks!