>Sounds interesting same as Igors mod or TAP? Yes, I checked a 1.8 A4 at the dealer today and it has also a "boost bypass valve" Colin, what do you get as reading on the OEM pressure gauge? I don't seem to get any reading higher than 1.3 Bar even when Paul's gauge read 10-15PSI of positive press.? Avi Meron 86 5Kcstq