Hood cooling improvement?

[Sykohtic]

So while its obviously not practical for a daily, which my car isn't, what would be the effect of having the rear of the hood popped up and the front latched down? I would think it would act as extra cooling because it would marginally improve flow through the bay in a car with no undertray. But then the problem is it would also have a possibility of creating some extra lift in the nose at some speeds.

Opinions?

[mikebloco]

I say just pick up and extra hood and start putting vents in it.

[TobyB]

You'd look goofy.

t

[CorvallisBMW]

Some people have been known to shim the roller brackets on the rear of the hood. Maybe it works, maybe it doesn't. It would definitely mess up the alignment with the fender line though.

Also be aware that all the hot air from your engine bay will also get sucked straight in to your air vents. Try removing the weatherstripping at the top of the engine bay, you'll see what I mean...

[Cabriolet]

ive run my car at 90mph with the AC on in 114F weather without issue.

so id fix the problem before you try to patch the issue with mods.

if you have a drift rat, pull the AC and put a pusher electric fan in the front that runs when the car is warm.

[modernist]

fix your cooling system. a properly maintained stock cooling system is totally adequate. I only have the viscous fan in mine (no a/c) and even in 100°F stop and go traffic, the temp gauge hovered barely above 1/4. at 80MPH climbing the sierras on a 90° day, it would go up to slightly below 1/2.

[CorvallisBMW]

ive run my car at 90mph with the AC on in 114F weather without issue.

so id fix the problem before you try to patch the issue with mods.

if you have a drift rat, pull the AC and put a pusher electric fan in the front that runs when the car is warm.

Ya... but have you run it at 0mph with the A/C in 114F? ;)

[Cabriolet]

Ya... but have you run it at 0mph with the A/C in 114F? ;)

Almost bc fuck Portland. Endless traffic. 107F AC on, no issues.

[Sykohtic]

Well, there's absolutely nothing wrong with the cooling system on my car, it doesn't overheat. So fixing it was never the point. I was just curious about other peoples experiences and thoughts about it as I was doing research.

The point would be to increase airflow and reduce air pressure in the bay by giving the updraft of air a larger escape path, thus reducing the amount of time hot air stays in the bay. Less hot air+=runs a few degrees cooler. And even if your cooling system works fine, which mine does, a few degrees cooler is usually a good thing on the track.

I was just curious as to whether or not this is something effective or not with our cars, learning the dynamics of it and all that. As it turns out, it isn't really useable in most track situations my car would be in. The car just wouldn't be moving fast enough to make use of it, so it would be a lot of wasted effort.

[Cabriolet]

i'd probably go for something like this, before pooping the rear of the hood.

http://www.r3vlimited.com/board/showthread.php?t=302929

[dnguyen1963]

Need more cooling?

[ELVA164]

Despite all the, uh, "tough love" in here, your idea would work. I've used it on two cars in our shop and I know for a fact all the fast Datsun 510 guys do it. To be clear, the greater effect is on under-hood temps, not cooling system temps. It does both, but mostly the former.

[digger]

Ya... but have you run it at 0mph with the A/C in 114F? ;)

ive done it in 115F (46C) no issues whatsoever, stock cooling system

[raudonis]

shim the roller brackets on the rear of the hood with washers. It is cheap, easy and 100% undoable.