Boost drop

[rx7ben]

Hey guys im hopeing some of you may be able to help me out with a little issue im having. When im hard on the gas up high in the revs im getting a slight drop in boost on my stock twins and i can feel the car hesitating abit. Its like  the boost is going up and down by a few psi. Now this only happens up high in the revs low down its fine.
 
Anybody have any idea what this could be.
 
Thanks

[m1tch]

On an FD its usually the boost solinoid or a slightly leaking hose, search on the forum under FD boost leak, you should have some pointers from there

[rx7ben]

Thanks ive had a look and this seems to be a common problem. If i wanted to change all of these where would i get the parts from.
 
Thanks