my friend has a 97 talon tsi with a serious boost problem .
when he gets up into the higher rpms (3500-4500 & 12-15 lbs boost) the car starts to surge.
it feels almost like when you bump start it but if i eez into the gas and keep the boost uner 10-12 lbs its ok .
he's changed all vac lines to make sure the are all good (no cracked lines) he also removed the mbc .
He's also done a boost leak test and fixed the leaks He also found out it also had the wrong plugs in it, changed that but nothing fixed this surge any suggestions guys as to whats causing this?