boost question

[F_T_F]

ok so recentely i upgraded my down pipe from the restrictive stock DP to a megan racing downpipe. i noticed something rite off the bat, i hit max boost 15psi and as my rpms climb i loose boost i thing something like 10psi at around 5500 rpms. prior to this when i was using the stock downpipe i had no problem, i held 15psi all the way through till redline.
i checked the piping from the turbo the throttel bodie and there are no cracks or boost leaks im getting ready to check for intake leaks but i dont think ill find anything just because im not having any of the problems i have had in the past with intake leaks. is a sign that i should give up my manual boost control and go with an electronic one?

 

[OneJoeZee]

Stock CT26? Boost taper is normal on the stock CT.

 

[Nick M]

You held restriction all the way to redline is another way of saying you held boost all the way to redline.

The stock CT can't out flow that downpipe. Joe is correct.

 

[F_T_F]

i figured it was something like that
thanks im getting the car dynoed today and i jsut wanted to make sure it was running at optimal levels.

 

[rumptis]

Engines request more air volume as they go higher in RPM's any turbo can only flow so much. So at lower RPM's our CT can supply enough volume to create enough boost to hit Fuel cut or max boost as you call it. As the engine speeds up and you hit the limit of the volume the CT26 can flow the boost will taper off.

This is normal and to be expected on a stock turbo. I have the same problem you do.