[Norm K]

Originally Posted by Bleedski

Here are my answers. The car is full stock; I don't know what RPM in 4th it hits full boost; it's not a recent development; there is no throttle issue; my idle is very smooth at 950-1000 rpm after warm up.

The bold text above provides the simplest answer to your question. It's easy, albeit not all that inexpensive to address your lag. An upgrade of your exhaust system (headers and muffler) and turbo will go a long way toward lowering your car's boost threshold. Lots of opinions as to which products to use although budgets are often the deciding factor. One thing you can count on is lots of help from the tremendous aggregate knowledge base of this forum. Understand that you'll have to put up with a fair amount of junior high school-type banter that frequently appears from seemingly nowhere in threads that, up to that point, were on-topic and you'll get along just fine here.