Hold on here. There's some half truths being applied wrongly. Yes, dynos can show different numbers depending on a multitude of factors. But clubhead is dynoing
his car on the
same dyno. Weather conditions in Singapore is pretty consistent so it shouldn't be an issue. It's not like we're comparing his dyno to someone else's in NY with 35 degree weather.
Secondly, the fan only helps to keep the engine cool. There is no "ram air" effect unless you're doing ~170+mph...and even then it is negligible. The engine is a vacuum pump. It sucks in air. It doesn't need air to be "pushed" in.
I'm a firm believer in using a dyno when you start modding a car. I can't see why someone would spend hundreds to thousands of dollars on "go fast" parts and skimp on a few runs on the dyno to save $70???
.