ill be honest, i have no turbo expierence......yet
but on the engine i work on, (marine diesel engines) there is no turbo lag, even with a good bit of pipe the intake charge runs through.

once the intake pipe is charged, it doesnt matter if the pipe is 10 inches long or 10 ft long, 10 psi is 10 psi. make sense?

 

I'm in full boost at 3800rpm with a gt67 turbo. You should go to youtube and check out the corvettes running the STS turbos into the 9's