I have been driving G25-660 ( AMS Omega 12), full built engine and Shep 1K trans for 6 months. The car makes 1146 whp and 963 ft-lb torque. At high rpm, there is plenty of power for my need. But lower rpm like 1,500-3,500rpm when I drive around regularly, it's felt so sluggish. Before G25-660, I had Bill Spray it Racing Stage 1 turbo with FBO. It was the fun car to drive as it has good response abroad wide range rpm. When I chose the G25-660, I had expectation for quick boost response while loose some top end HP compared to 1300 package. Currently I feel like turbo lag where it should not be as these G25 turbos are small.
I am confused. What could go wrong? I don't think boost leaks. Tune not optimized at low rpm? Any suggestion?