Originally posted by Rudy Yarbrough
If you add a pusher fan you will be pushing engine bay air through the IC and not outside cool air. This plus the aerodynamic effect of the rear deck lid will be completely negated. Why do you think that the engineers in all of the automotive companies decided to pull the outside air in instead of pushing the hot air out through the radiator/IC? I have heard the same argument about the AC condensor in the engine bay that if you wanted a helper fan it should be a pusher. All you have to do is feel the air coming out of the engine compartment in traffic to realise that this is a no brainer. What would make more sense would be to route the IC discharge air out of the engine bay without any restrictions and be discharged over hot componets such as the turbo or manifold area. Where am I going wrong on this?
* The air in that area of the engine isn't really that hot. There is a large rubber gasket designed just to keep the "hot" stuff (exhaust, CAT, headers, etc...) from heating up the "cool" stuff (intake, intercooler, etc...). I will be moving so much air that my temps will be nearly ambient.
* Porsche wanted a high pressure area above the spoiler to force air into the intercooler and reduce lift and drag. In stock form, the air isn't very high pressure up there (preventing it from being forced through the intercooler). My fan will INCREASE air pressure in this area, aiding aerodynamics and engine cooling.
* "...the engineers in all of the automotive companies decided to pull the outside air in instead of pushing the hot air out through the radiator/IC?" Because the engine is in front on most cars, and blowing air into the wind doesn't make sense.
* Yes, it makes sense to dump post-intercooler air out of the engine compartment. However, that doesn't solve the relatively low natural flow of air through the intercooler - the fan does.