Could someone help.

I have a Subaru 1998 what i think is the running standard boost. When I am at say 80 and I accelerate in hard (5th only) when hitting full boost it cuts out the boost, if I eccelerate gentle its fine.

Everthing else is fine through the gears 1 2 3 4 accelerating hard

I am thinking overboost!!!!!

 

Sounds like it could be but have you checked the plugs and coils??
Plugs gapped wrongly or cracks in the coilpack??

 

Cheers mate. Going into the garage on Tuesday for a gasket replacement so I will get this checked.

 

I would go with the overboost theory and would clean out the boost control solenoid with brake/carb cleaner.
Do a search on how to clean it out its quit simple.

 

i had this the ohter day and mine has just been remapped to 350 and it was doing the same thing i had the spark plugs cleaned and gaped and it fine now