Jaeger

This vent will blend nicely for the a 928 that generates extra heat in the engine bay, especially for a 928S version with the old body style, it has alot of the same design attributes to the vent as does the 928. it appears wide enough to be adequate, yet narrow enough to fit our somewhat narrow hoods.

Speedtoys

What is this extra heat?

hacker-pschorr

It looks stupid on the Mustang.

For an all out track car sure......anything on the street, waste of a good sheet of aluminum.

Jaeger

i like to make toast while i am driving so i keep a couple toaster ovens in there, how about you?

That and the Flame throwers....

SeanR

This has worked very well on here.

Jaeger

Not bad at all, I bet it helps a lot, i wonder what kind of temp drop you experience before/after a sprint on a warm day.

And would it equally cool the two toasters and my proposed George Foreman grille i plan on utilizing under the hood...?

There is something about it though, it does not catch my artistic eye's fancy where the two vents butt up against one another.

MjRocket

Here's one from the cobra on a 928 in the wild.

No Affiliation.

antlee928

I'm thinking that, if indeed, we need to add more cooling to under-bonnet temps, what would be the most effective yet aesthetically pleasing way to do this. Will bonnet vents such as that proposed or any other necessarily reduce under bonnet temps. I am also wondering is the under bonnet temp issues are when the car, after a run, is then parked. I normally open the bonnet after parking my car in the driveway or in the garage to allow for faster cooling and to reduce any "baking" effects. Good question though to explore. How would Porsche address this problem today??

Ad0911

Isn't the cover under the radiators/front of the engine designed in such a way that it creates a slight underpressure behind the radiator while driving. And if it is not fitted, hot air will stay in the enginebay?

jeff spahn

My thoughts exactly. That's why I put belly pans back on.

I too open hood when parking for the end of day.

hacker-pschorr

Who says there is a problem? If the car is running too hot something might be broken.

They addressed the problem back in the 70's by doing extensive testing with the 928 in extreme desert conditions and designed the cooling system accordingly.

Step 1 - Make sure everything is working as the factory intended
Step 2 - Install both belly pans and the front spoiler

Cameron

I have had three 928's in Florida and none of them have had overheating problems. Even running the Supercharged GT on the track at Sebring in Florida in August/September. I suspect that if you have an overheating problem, you should troubleshoot the stock system.

WallyP

I am reminded of the time back in the day when MG upped the power on the MGA 1600 Twin Cam and added two underhood vents. They later discovered that at-speed air flow was into the vents, not out. Air pressure over the car can do non-intuitive things.

Second thought - the under-hood air flow is designed to flow over the engine and out, cooling things down. If you do manage to give the air an easy early exit, will less heat be carried away? Perhaps red-hot exhaust manifolds and pipes need some cooling air flow?

hacker-pschorr

On modern day Aston Martins with hood vents this is what they are for. If you look down the side of the engine are heat shields with ducts / chimney's leading up to the vents.

You can see the four "chimney's" on each side of the engine flanking the throttle bodies in this photo:







But again....what is happening with stock 928's after all these years that leads anyone to think we need such heat dispersion? Todd did a lot of data modeling with his twin turbo design and marveled at the way a 928 is designed to direct air leaving the radiator over the manifolds and down under the car (.....another important reason to have belly bans installed). Trying to "fix" this could actually create a new problem.

Tom in Austin

I agree. With the possible exception of the oil cooler on the 90+ cars, I would think Porsche 'sweated' all aspects of cooling and air flow to optimize for all driving conditions & climates ... as many of us have noticed when we run without the belly pan and see a higher reading on the temp gauge