upper or lower grill block for volvo s40

[chefdave]

Hi for front grill blocking or lower valance vents which would be best for aero. Volvo have made a front valance block to fit my volvo s40. Would i be better to follow volvo or just go with grill block. My volvo is fitted with a trip computer which measures temp in 1c increments so i could measure temp variantions quite accuratly. Any comments or advice will be gratfully received.
thanks
dave

[spacemanspif]

any links or pics of the Volvo options?

[chefdave]

Hi hope this link works http://i783.photobucket.com/albums/y...psckkhdxdq.jpg

[chefdave]

Bottom vent is just under number plate. Yes its a 2001 model but mine has same front body panels.
thanks
dave

[spacemanspif]

Interesting. Usually this site recommends blocking the upper grill. The reason for this is engine compartment turbulence. Air coming across the bottom of the radiator doesn't have to go as far, or jump through as many hoops, to exit the engine compartment as does air that comes in through the upper grill. Not sure the difference would be noticeable between the 2 options, but a factory grill block is probably going to fit nicer, look better and require less work than a DIY.

[whatmaycome14]

I would block as much as possible without overheating. Start with the top and go from there.