[BilLster]

it would realy depend on where your boost gauge is , if your reading manifold boost (back pressure ) or at the exhaust side
of a waste gate.

the best is to inject n2o into the intercooler for cooling things down,

I still have the timing pulled when ive used n20 with the old turbo set up and motor. but i can understand the theory Gale banks used n2o to cool the exterior of his intercoolers so it wasnt getting injested by the engine just cooling the charge.(my current purge valve is aimed at my intercooler)

I used it to offset any lag.at the start and it shut off after 5000 rpms

I would try the smaller jets with the same timing at the top end of a run and check plugs. just remember your exhaust might already be taxxed with 18lbs of boost.