Better aero: UGB or LGB?
 

I thought i read somewhere that a upper grill block was better for aero but I couldn't find it today. I have used both, but w/o a scanguage to test it is though to say. My engine runs at the same temp with either the LGB or UGB. I might leave the top closed and even close off some of the bottom. Thoughts?

It depends on the car. I have both blocked. The upper is tiny, though, and the lower is huge. I use it for the quicker warmup and not so much for the aero. My drive doesn't take me above 55mph.

See how much bigger the lower is. It'll clearly make more difference than the upper.
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grille block
 

I agree with Pale.Since the cooling system is credited for producing 12 % of overall aero drag,it may not be so important as to where its blocked,rather that its blocked.With airtight inlet and outlet ducts,the drag is virtually eliminated in some of the concept cars,and most race cars/boats/planes.

See post 15 & 16.

http://ecomodder.com/forum/showthread.php?t=1707