http://www.infinity-hobby.com/main/a...rticles_id=172
"In the air:
In first few flying, I don't feel too much different until when I take out the Exhaust Gas Cooler. But I don't believe the 7'c different won't influence any performance. So I change the way of testing. I fly the heli alternating with exhaust gas cooler and not. And I have also extended the flight time from six minutes to nine
Minutes. "
as how describe in heli article..