boost problems

[khsdm]

my friend has a gsx and just got his car back from a rebuilt turbo, what the problem is when we get into boost we get up past about 5 and the car will jerk and bounce back off the boost gauge, its almost like it has a bad plug and not getting a good spark and when the car jerks its losing its boost, let me know if any one has had this problem before, maybe the wastegates connected wrong, but didn't see any signs of that. please let me know

 

[I-luv-em-all]

check all the simple things first, plugs, wires, fuel filter, boost leaks.

 

[khsdm]

well i was also thinking that when we re rerouted the dumptube from the wastegate back to the exhaust it mght be not getting all the exhaust out quick enough and backing it up. its the agp kit that has it shoot out the side