If you want to change it. without splicing wires. Pull the harness on the right side of the engine deck and swap the polarity, brown and black wires. Never thought such a simple thing would cause such controversy and discussion

 

Golly....isn't this an interesting thread

Personally....I want to find a way to make the fan blow side ways.
What would be the wiring proceedure for that?

It does make some sence it blows down........'up' would actually oppose incoming air as you drive......in effect limeting engine ventilation.
As for all other cars sucking air from the bottom and out the top........are those cars w/engines in the rear & with top ventilation ahead of the rear wing?

 

Let's keep arguing about this binary possibility, and keep this thread going, shall we?

I still say it makes more sense for the fan to blow up and exhaust. I believe that area above the fan is a low pressure area. It would naturally suck the air out. A fan blowing into the engine would simply be fighting the natural suction, and the fact that heat rises.

 

Mine blows down.

 

The electric motor probably only has thrust bearings for rotation in 1 direction. Running it in reverse may wear it out.

 

I just took delivery of this "squirrel cage" fan as a replacement for the stock fan.




Or I may go with a passive exhaust system.

 

Just checked mine again. It blows down whether the engine is running or not. I have no way to check it when the car is moving but would assume that it blows downward since it'd be kind of hard to change fan direction.

Come to think of it, most cars have fans near the radiator. The TT engine compartment fan is not. Not sure how that impacts the design. One hypothesis is that the layout of the components in the engine bay makes it that the hotter elements sit below the cooler ones. And the cooler ones has lower heat tolerance. By blowing the air downward, one prevents the situation where the bottom components "grilling" the upper components like a convection oven.