I put a cam and heads on my 94 Z and left the front spoiler off when the job was done because I knew I would be getting back under there. The car was running hot; at the last mark before the red until the fans came on, which would bring it down to the middle mark, and then back up again. Even on the highway. I figured it must have been the front spoiler and so it was. I put it back on and the temperature is back to normal.
Not surprisingly, the spoiler affects the air flow around the radiator a lot. I heard on TV that the requirement of a plastic strip about half an inch high on the rear spoiler of LeMans prototype cars brought their top speed down by like 30 mph. Airflow.

 

Do you see any way air can flow through the front bumper and support to the radiator? No? Me either.

The deflector's there for a reason

 

Thankyou kind sir. I thought that was what I just said.

 

No? Thru the grill? Why not?

 

1: There IS no grille.
2: Even if there was, there's a 25 pound slab of steel called a bumper reinforcement in the way

 

Thanks for sharing! Many here take this knowledge for granted but there are quite a few that don't know and find out the hard way (like you did! ).

With many ground effects kits, a larger air dam is REQUIRED to maintain airflow to the radiator. The stock air dam/deflector doesn't go down far enough to scoop the air up when front ground effects are installed

 

And for those of us with ground effects and lowered cars, know the exact part number and price of that piece, b/c we get to order at least one a year

Im working on a sheet metal one right now. It will be LOUD when it hits, but at least it wont break. Im on my 3rd wings west dam.