I keep reading this as you saying air comes out of the rear of the hood, while driving at speed. That is not the case at all. Air is drawn from the cowl area IN under the hood at the ouside edges (say from the outer rear corners extending 8-12" towards the middle of the car). In the very center of the hood air is not being drawn into the hood or it is being drawn-in in such small quantities it was undetectable with the crude methods I was using.

When driving the airflow is something like this in the hood and cowl area. There Is NO inward air flow in the center of the hood behind the triangle.

I would like to see where the chalks are placed to raise the hood. Raising the center won't do anything. Raising the sides would create more ambient airflow down into the engine bay and over the engine.

 

Time for a custom project?

 

I don't think opening the side vents to the engine bay would give the desired effect.

 

Today, on the way home. Weather Sunny and humid 100F or maybe more. 100 according of external temp sensor.
I was driving with an average speed of 85 MPH (close enough to what you asked) for about 30 miles.

I monitor the condition of the engine practically all the time, so believe me i know how it runs, in what conditions and at what temps. The laptop is always open on the passenger sit.

Average temp drop is 6-10F depending on the intensity.

I monitor the condition of the engine practically all the time, so believe me i know how it runs, in what conditions and at what temps. The laptop is always open on the passenger sit.



I am tired of this bullshit. For some reason i ended being in a position where I feel like I have to excuse myself. I did it. It works for me. You don't think it is good enough for you, spend $800 on a vented hood, it's your money. I'll find something else to spend mine onto.

I remember a bunch of naysayers telling me how a turbocharger won't make boost the back of the car. I built it and at some point I had difficulties keeping that turbo from over boosting pushing 16 PSI at 7K rpm...
For every good thing there will always be someone who'll try to crap on it. Apparently this case is no excetion.

 

16PSI would blow a 10:1 motor on pump gas almost instantly.

And if your turbo was doing that at load you went way to large on your compressor.

 

 

You see?
I am done here.

 

How about some pics. I want to see where you put your chalks.

 

http://picasaweb.google.com/vdarevsk...05066507710594

http://picasaweb.google.com/vdarevsk...05075097645202

http://picasaweb.google.com/vdarevsk...05087982547106

 

thank you. I wanted to be sure I understood and a pic is worth 1000 words. I just found your DIY - sorry for not looking first.

 

U'r welcome

 

What about using hood dampers?

They raise the hood on the sides and rear.

That should help. Maybe not as much as you want, but do both, chalk center and dampers.

What do you say rotorocks?

 

rotorocks

Why do you keep the enginge cover on if you want to get rid of heat?

 

just use washers to space the hood on the hinges. no worries of placement or bending anything.

 

Driving without it changes nothing as far as the effect of cooling, but driving without it for some time, and you'll begin to see the paint on the hood fading and peeling off sooner.
It's primary purpose is to shield the heat radiating from the engine, not to block the hot air.

 

Engine cover directs airflow. Search.
Hood dampers shouldn't raise the hood. If they do, you are using the wrong ones. Search.
16PSI and 10:1 compression have nothing to do with whether or not you will blow up your motor. Its all about ignition timing and fuel. That was just a stupid post, so I won't bother to tell you to SEARCH.

BTW - Its "chocks" not "chalks".

 

best post all thread

sorry for going so far back into the thread, I've just finished skimming through.

you can already get these, they're very expensive though.

Roberuta Cup Kits, sold through Top Secret
http://www.topsecretjpn.com/roberuta.shtml

ram air seems intuitive (even if wrong) - and has a cool name, it sells, that is why it is made. Being popular in the aftermarket doesn't mean much, the aftermarket is full of heaps of **** that people swear works... look at those buzzcans on hondas "its like another 50hp bro", or the open pod filters.

I've got an article where they run som CFD experiments looking at the pressure built by 'ram air' on an F1 air box with various radii for low and high speed flow, at the speeds an F1 sees it made all of stuff all difference. It isn't ram air giving you better performance - it is cooler air, and a less restrictive intake path giving better cylinder filling..erm.. combustion chamber filling in this case

IMO so much focus should not be put on just getting air out of the engine bay, that might be nice, but really the goal is to promote as much air flow as possible through your coolers - radiator, oil, ps, trans, etc. Better ducting is the way to go where possible. If you take a look at race cars like JGTC Supra, there isn't really any venting for underbonnet air, but there is MASSIVE ducting into and out of each cooler to get the air flowing through it nicely.

IMO the guys who keep harping on about breaking out the wool tufts (and having thermo couples all over the joint so you can log what is going on) are on the right track, without the data you might hit on something that sorta kinda works, but it is unlikely to be the best way (whether you have any constraints on how wild you wanna go or not)
sorry for the big post.

 

The engine cover does direct the air flow, but what about a s/c engine. Would it worth it to alter the existing engine cover or design a new one? With the reconfiguration of the whole throttle body area I'm not sure if it would help.

 

I'll also add that if you pack in enough air this way, you could increase the pressure in areas under the hood and actually risk the chance of decreasing your radiator and oil cooler efficiencies by restricting their airflow path.

The proper way to increase cooling is to direct more flow underneath the car, direct it to another low pressure area, or with a vent create a low pressure area by having large amounts of flow going over top of a vent which creates suction.

race cars have sealed cowls....

 

Why are people comparing race cars to daily drivers in terms of cooling.

Honestly please do tell how you could risk oil cooler efficiencies from raising the back of the hood 1/2 to 3/4 of an inch. This isn't a 3-4inch cowl like on a mustang.

My car gets really hott when I'm not moving and I dont like that considering it was 101deg here yesterday.

 

Oh really? Hmm, then I guess my friends turbo Hayabusa motorcycle that has an 11.0:1 compression and runs 17.5 pounds of boost is just a figment of my imagination then. Damn, I gots to lay off the drugs.....

Like MM said, compression and boost don't matter, it's the fuel and ignition you have.

 

I wouldn't expect you to be spreading this age old rumor (going back to 2003 when the car was released). I've just been through dozens of threads regarding the cover. Anyone who believed it did anything also believed it forced the air out through the fender vents. Everyone points to Canzoomers (where the H did he go?) test where he saw 10 degree cooling. Horse manure. You're the king of "proof" and results and in this case it's non-existent.

Look at the back of the cover for any actual "channeling" capability, it's proximity to the hood (to serve the same purpose) and tell me that it really does anything.

 

Vents hood outside high pressure area......

S

 

LOL

 

ignorance FTW!!!