Quote:
Originally Posted by NeilBlanchard
I would block the upper grill completely, and cover much of the lower grill and then a straight down spoiler that extends only a bit below the lowest protrusion under the front part of the car. Do not go closer to the ground that needed to "cover" the lowest portion.
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Good point about blocking the upper grille. Something I should have realised from human powered vehicle experience, the best place for a low-velocity ram intake is always the stagnation point, as power lost is a product of pressure and velocity - the upper grille would have higher air velocity, thus higher losses. Should be easy to fabricate, too - in fact I'm tempted to go out and tape a bit of clear plastic over the upper grille right now
Quote:
Originally Posted by aerohead
I'm going to vote for 'b' also.And for the same reasons mentioned by Sven7.
The 'Spirit of Ecomodder.com' nose is like (b),with a bit of layback and is already producing induced drag (downforce).
FIAT research shows the same Cd for 'straight' and 'layback',so there's no apparent drag benefit to the layback.
The forward-projecting angled shelf or splitter would increase the induced drag,so unless you're going to track race the thing,there's no point.
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I would mention also,that if the distance from the nose, to the face of the radiator is less than the height of the radiator,then you might consider moving the nose forward to that dimension.
It will allow the minimum entry opening (if you do an airtight duct ),and also allow some plan curvature/radius which would help in crosswind drag reduction.
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Induced / parasitic drag is a good point - but only if extra induced drag of one option > extra profile drag of another
. The bottom edge of the common (b) option also looks a heck of a lot like the edge of a flat plate perpendicular to the wind, too - or a sharp corner, if combined with a belly pan, neither of which tend to be great for drag. The sharp corners with the other options are no better, of course. What about something like this instead (call it option (f) )?
I like the idea of lengthening the nose, but I'm not sure how I'd go legally speaking there -apparently an engineer's approval is needed for 'lengthening a vehicle' here. The intent of this is to do with changes in wheelbase and gross changes in hood/boot length but the wording is ambiguous and cops looking to meet their (allegedly non-existent) ticket quota are known for 'generous' interpretation of the rules at times. A subtle increase (maybe 5cm) might be doable, though I'm not sure it would be worth the effort. The plan view of the bumper is a bit 'flatter' in the middle than near the edges though, so that much nose extension, by continuing the curve established at the sides, could be made to look very natural indeed...