V-Mount Theory.....
 

I am def. planning on fabbing up a V-mount intercooler for my car and mentioned this to a friend who is an automechanic. He brought up an interesting point that seemed to make sense somewhat, but need more opinions?

He said that if there is a duct (say metal sheet to direct air to intercooler) and all that air was going up into the engine, then it would produce upforce when it went throught the intercooler and hit the hood and stuff. The air has to go somewhere and it just happens to want to push up on the hood creating lift at higher speeds.

I asked if the downforce of the air hitting the duct and the radiator counteract that that is hitting the hood. He told me probably, but it wouldn't hurt to have a vented hood just so that force isn't present.

I don't know how accurate this really is, but figured since v-mount intercooler setups seem to be on the tip of everyones tongue, I would ask for your opinion.

Please comment/argue, whatever you like. As if you wouldn't anyway:D

M-P

ask dcrosby, he has one and seems to have a lot of info on what he does....

I think that is why most people use a vented hood with a v-mount. It seems it would keep things working more efficiently as well. I certainly have the vented hood planned when I go that route.

Ask Cossie, he track one with V-mount. I doubt there is a big lift to the car as you are driving less than air plane take off speed with smaller lift area of the hood compare to aircraft wing. :p:

V-mounts and vented hoods go together because the point of the effort is to achieve maximum flow through the intercooler. Why else would you bother with the mod otherwise? So I don't see that the "lift" issue your mechanic pal raises is a relevant concern.

Does your mechanic think that air only hits the underside of the hood with a V-mount setup? The stock mount may not let quite as much air through, but it works much the same way. Air is always being directed through the engine compartment, I don't think your mechanic's concern is that valid, but I could certainly be wrong. I'm not an aerodynamics engineer.

He is right in concept, but the difference between a v-mount and the standard radiator setup will be neglible in reality. Remember, the standard radiator is angled just like the intercooler of the v-mount. A better arguement is that flow going through the radiator is now going under the car with the v-mount, which could cause turbulence under the car, resulting in lift. Again, it should be neglible, because the amount of air actually flowing through both the IC and radiator is very small compared to the amount of air that goes around the nose, both over and under. Any hole in the nose for a heat exchanger essentially represents a stagnation point as far as airflow is concerned. That is, the velocity of air right in front of the hole is essentially zero, so it creates more drag than anything else.

I've got a V mount without a vented hood. Just haven't bought the hood yet but it's on the list... I haven't noticed anything different in driving the car besides lower temps. I don't think the so called "extra" air flow would change anything on the car.

Dedicated ducting to flow air from the V-mount to the outside will result in cooler air intake temps. It's not the air that hits the IC, its the air that passes through it.

once the air thru the nose is divided into two paths for each core, the exit velocities will not be high enough for significant lift due to impact on a small area of the hood.