Fair enough, makes sense. But surely it would be more advantageous (even if only slightly) for it to be sucking air that hasn"t been through a hot radiator first? Or am I just clutching at straws here

?
I'm not saying it's not beneficial to have cooler air entering the intake, just that it's not as important as the cooler compressed air entering the intake manifold. This is why anything you can do to provide cooler air prior to entering the intake side of the engine, is far more beneficial ie,
(intercooler air/water, intake & TB spacer plenum, water injection, etc). These will be far more important for producing hp & tq.
The compressor/turbine will add additional heat to the air flow due to its inherent function and location but a proper sized intercooler, will quickly cool the compressed air moving thru it.
Now, does a higher volume & velocity cold air intake help? Yes, as there is more volume of air entering the engine. Larger volume of air in and out, thru a more efficient intake and exhaust scavenging, produces better performance. Everything on the intake & exhaust side, does its part and add to hp/tq production.
This is why
ram air systems were developed, first for naturally aspirated engines and later for turbo/supercharged applications. Speaking of this, reminds me to check in with Dan @ Velossa Tech and see how the; i30N Ram Air Snorkel is coming along.
After all, the engine is nothing but a complex compressor.
