Barbs Aero MakeOver

[Lazarus]

Originally Posted by metroschultz

She
Who
Must
Be
Obeyed

Funny

[johnpr]

great work, i really like how that is turning out

[diesel_john]

caution, if your radiator fan turns on when your moving, then you lose mpg's because of the extra electrical load. so that's the cue to unblock.

i wouldn't block the lower opening because of PSteering, and transmission cooling. i would make sure lower opening sends pressurized air to the whole radiator.

looks good

the little lady calls my car the flintstone car. i think that's good. isn't it...

[metroschultz]

I searched all the threads.
Used the search engines.
Looked in GS.Org
and @ MetroMPG,
& Auto Speed
& CRXMPG
& Google
But could not answer this query;
Which is better, if you are only going to do one,
Upper Grill Block
or
Lower Grill Block?
HHMM
any takers, I welcome and relish any & all discussion and information.
as it stands my plan was to make the lower grill block removable so I could make adjustments according to engine heat.
But,
That is the second time someone has suggested leaving the bottom open for the cooling of parts other than radiator.(not both on this thread).
So that having been tossed into the ring, my new plan for this weekend is to make the lower air dam, and maybe smooth the rear underside.
Thank You,
S.

[MetroMPG]

I recalled basjoos weighing in on this question and found this nugget (which he posted at GS). Makes sense to me.

You'd get better results if you blocked the upper rather than the lower grill opening, especially if your car doesn't have underbody panelling. In the absence of underbody panels under your engine compartment, all of your cooling exhaust air is going to end up under your car, adding to the drag turbulence down there. Some of the air that currently isn't entering your blocked lower grill is going to end up under your car anyway. But if you block your upper grill, all of that air is going to end up going over your car, where it creates less drag.

If you look at many sports cars (example: 1992 Camaro, and also on the 92-95 Civics), you will see that they place their grill opening very low on the front of the car just for those reasons mentioned above. On most cars, that upper grill intake is dictated by the automotive styling department, since many people don't think a car "looks right" unless it has a grill opening at the upper front of the hood. That look is a holdover from the cars of the 30's where the entire front the the car was designed around a large, tall grill.

[Daox]

The upper is usually prefered normally for aerodynamic reasons. If the upper grill is causing flow seperation it'll effect the aero of the car more than the lower, becaues as soon as the air hits the underside of the car its probably going to seperate and cause drag. In your case of putting the block behind the grill, I don't think it'll matter as much.

[metroschultz]

Metro,
I thought I read that, but could not find it when I went looking. Thanx.
DAOX,
I do realize that the grill block is less effective from behind, when I find a source for actual clear plastic ~6 mil. thick I will block from the front. Till then some block is better than no block.I still have to keep the OEM appearance. Thanx.
S.

[tasdrouille]

The block is not much less effective being behind the grill. All those fins in front of the block will form pressurized air pockets at speed that will effectively have almost the same effect as a smooth surface.

[metroschultz]

true what you say Tas.
I remember reading that tidbit of info before I made the block.
IIRC they are called "Trapped Vortices"
nice to know someone else is on the same page as me.
S.

[aerohead]

I'm reluctant to make any general statements.I've seen carmakers do both upper and lower.Chrysler has some fake upper intakes,today's Yukon HYBRID has fake lower driving light openings,and a minimized radiator opening.Dr.Tim Maxwell at Texas Tech told me that on the original Taurus,that air actually came "out" of the upper grille opening.I doubt there's any hard and fast rules.As members have mentioned,proceed with diligence,on the look out for heat-and-serve engine parts.