If I understand correctly, a bigger turbo moves more air which in turn cools. HOWEVER, as I read more posts on this fact there seems to be conflict from my point of view. I have a hy 35 that spools and cools at 1500rpms with only ez. I have 3:55 ratio and usually average about 1750 rpms going down highway towing. I will be getting mach 1.6 this coming year and probably will need more air. From what I am reading the 62/12 for example cools well for this set up (ez, mach 1.6) but the benefit is best recogized after 2000 rpms. This defeats the purpose for me as the majority of run time is 15-1800 rpms. Is there anyway to get air moving at 1500 to spool larger turbo or is this a trade off of which I am not sure I see a benefit most of the time for my high ratio towing outfit. Thanks in advance.

 

a 62/12 will spool faster, but not cool as much as a 62/14 at higher rpms. As far as I know, with the setup you want, it will cool fine.
I am getting a 62/12, have a comp and 275's. I will be towing and that is why I went this route.