Cowl induction hoods

[Crazyrabbit]

I was looking at a new Mustang the other day, and it occurred to me that a really Boss cowl induction hood could lower the drag of a vehicle. Suppose it raised to 1/3 the windshield height or so, and was the full width of the vehicle. A lot of the windshield in my car is only useful for looking at my hood, which is not helping me navigate at all.

[aerohead]

Originally Posted by Crazyrabbit

I was looking at a new Mustang the other day, and it occurred to me that a really Boss cowl induction hood could lower the drag of a vehicle. Suppose it raised to 1/3 the windshield height or so, and was the full width of the vehicle. A lot of the windshield in my car is only useful for looking at my hood, which is not helping me navigate at all.

I have done this mod on my truck and cannot tell you if it helps or not.It's never been independently evaluated.
There are some wind tunnel researches published in Hucho's books which suggest that such a mod would not help with rag reduction.
The premise of what I did was to reduce pressure spikes/suction peaks at the A-pillars/windshield header,as would occur with a full,compound-curve windshield as found in aircraft,submarine sails,Bonneville LSR streamliners,and GTP race cars.
My experience is that the hood 'blister' does not 'hurt' mpg.

[dylman3]

I am pretty sure I saw your truck on the site earlier and was inspired. How did you make yours? I do not have experience with any body mods yet, but I was thinking the same thing, and of how cool it would look if you put a 4" induction cowl hood scoop on top of a 2" flat Induction cowl hood. Or just a single hood with that layered look. Since I've looked on the internet for an hour with no such thing, I don't know if I have the same aesthetic tastes, or if its a bad Idea aero-wise, but I want to do something along those lines, just cant afford all that stuff.

[gumby79]

The intention of a cowl induction hooduas to use the high pressure at the windshield to improve volumetric efficiency, forced induction with speed providing the force.

What if insted of trying to force the air into the engine, we vent it through the front wheel wells .

[freebeard]

The counterfactual case:



A low hood and bubble top. I think aerohead is pursuing something similar with his Viper windshield overlay.

[gumby79]

Agreed

I think Aerohead is going for an equal pressure from radiator to tail of the canopy or at least to the apex of the roof. Based on the http://ecomodder.com/forum/showthrea...ion-34798.html articals.

For the rest that are not willing or able to custom build a front greenhouse there is a high pressure zone at the bace of the windshield .similar to theas

[aerohead]

Originally Posted by dylman3

I am pretty sure I saw your truck on the site earlier and was inspired. How did you make yours? I do not have experience with any body mods yet, but I was thinking the same thing, and of how cool it would look if you put a 4" induction cowl hood scoop on top of a 2" flat Induction cowl hood. Or just a single hood with that layered look. Since I've looked on the internet for an hour with no such thing, I don't know if I have the same aesthetic tastes, or if its a bad Idea aero-wise, but I want to do something along those lines, just cant afford all that stuff.

I stripped the facings off of polyisocyanurate insulation board from Home Depot and pinned a foam 'skin' onto a foam skeleton,then fiberglassed all that in place,on the truck,using polyethylene drop-cloth as a release barrier.
I won't know it's effect until I can get to DARKO,so I can't even recommend it as a mpg-saving mod.
In theory it might improve the sectional density and pressure/velocity profile of the forebody,plus direct the air in the vicinity of the side mirrors at a lower local velocity.
I would not recommend this area for induction of any sorts.The forward stagnation point would be the place for that.