Have a look at my thread in forced induction, you'll see my dyno curves for AFR and boost. The car, once fitted, with a aftermarket ecu will fatten up the mid range hugely and should make the turbo spool quicker. You can see from about 4700rpm to 6200rpm I'm running an AFR of 11.0/10.9 thats hugely rich, plus the stock ecu is retarding the timing as well. Lets wait a few months till the fuel system is sorted and the ecu in and tuned and see what happens. For the power I wanted, and the engine being on stock internals, I had to find a turbo that would give me enough HP at a lowish boost and I think you will be hard pressed to find a aftermarket turbo that flows enough for a decent amount of HP without a bit of lag. I think the HPI r34 turbo is a ball bearing and that hits full boost around 4000rpm. I agree about the stock turbo being great for spool after driving my car around for the past few days, but the hit of power is amazing when it does spool