Wasting that heat more efficiently

[Daox]

I've never actually made it, so no pictures.

[redpoint5]

Originally Posted by Daox

I've never actually made it, so no pictures.

What gains did you experience with a full grill block? How are your temps?

[Daox]

Its very hard to say. I never did ABA testing. Also, I put it on in fall when the temperatures were dropping so it was very hard to tell as my mileage was dropping. The one thing I noticed was a slight hill I go down. In winter I used to slowly loose speed going down it. With the grill block I was able to maintain speed going down it. Also, warm up time was reduced a fair amount.

[wyatt]

Originally Posted by redpoint5

Interesting idea. How about a hood made of aluiminum that acts as a heat sink? The problem I see with both of these ideas is the lack of air movement when a fan needs to run to cool things off. My question is, how much can one gain by entirely blocking off the grill?

I believe this is a no go. Vehicle manufacturers have to adhere to certain codes, one of which says that exterior parts of automobiles can not get above a certain temperature. I am sure that pumping 200F+ coolant up near the hood would burn someone that happened to touch your hood. Safety first!

[ConnClark]

Actually the best way would be to use the radiator to reduce drag. The P51 did this and actually gained thrust from this technique above 300 mph.

two papers on the subject

http://naca.central.cranfield.ac.uk/...rc/rm/2147.pdf


http://naca.central.cranfield.ac.uk/...rc/rm/2302.pdf

[NiHaoMike]

Originally Posted by wyatt

I believe this is a no go. Vehicle manufacturers have to adhere to certain codes, one of which says that exterior parts of automobiles can not get above a certain temperature. I am sure that pumping 200F+ coolant up near the hood would burn someone that happened to touch your hood. Safety first!

What about a black car on a sunny day? And what about the exhaust?

[redpoint5]

Originally Posted by wyatt

I believe this is a no go. Vehicle manufacturers have to adhere to certain codes, one of which says that exterior parts of automobiles can not get above a certain temperature. I am sure that pumping 200F+ coolant up near the hood would burn someone that happened to touch your hood. Safety first!

You are really making the idea appealing now. People that touch my hood should have something remind them not to be touching my hood. Scalding temperatures should do the trick. I always liked the look of the unpainted Delorean, so maybe brushed aluminum would give the car character. Anyone know the MPG penalty for a flux capacitor?

Originally Posted by ConnClark

Actually the best way would be to use the radiator to reduce drag. The P51 did this and actually gained thrust from this technique above 300 mph.

two papers on the subject

http://naca.central.cranfield.ac.uk/...rc/rm/2147.pdf


http://naca.central.cranfield.ac.uk/...rc/rm/2302.pdf

Interesting... so I just have to go 300mph and have a jet engine to implement this fuel saving trick. I've got a few mods to make...

[redpoint5]

Originally Posted by NiHaoMike

What about a black car on a sunny day? And what about the exhaust?

Black paint won't scald nearly as badly as aluminum backed by 200+ degree water. It has to do with thermal capacity.

You bring up a good point about exhaust. My motorcycle has a very exposed exhaust that will give an instant 3rd degree burn if you aren't careful. If I ever figure out how to cost effectively implement an aluminum hood, I'm all over it.

[ConnClark]

Originally Posted by redpoint5

Interesting... so I just have to go 300mph and have a jet engine to implement this fuel saving trick. I've got a few mods to make...

no yo don't need a jet, you need something that will expel heat through a radiator. Using this technique you will experience reduced drag at lower speeds and a possibly positive thrust above 300mph if you do it right.

[ConnClark]

One more paper

http://naca.central.cranfield.ac.uk/...rc/rm/1683.pdf