Hood modification

[myfirstbonnie]

I have been thinking of a way to get some airflow across the engine in the chicken. Mainly across the SC for a cooling affect and to force the heat from the headers down the back of the engine.

I was looking on another forum where soemone was putting "scoops" into the front of the hood on their GP. Like the ones SLP did.

Here is the work in progress from here http://www.azgmperformance.com/forums/v ... 113&t=3088 but you have to registered to see the complete write up.



Here are my thoughts and some more investigation will follow:

The 2k+ hood is aluminum with a fiberglass inner shell. Putting similar scoops in and only having them open up into the waffle shell. This would require the ability to weld aluminum or find someone who can once the fab work is done. Then open strategically placed openings in the fiberglass layer to allow the air to be forced over the SC and TB and with the seal across the firewall, forcing the air down the back of the motor and under the car.

Right now I am thinking of getting a second hood and doing some investigation.

Thoughts?

[clm2112]

Fiberglass to the rescue

Open up two slots in the aluminum skin that make up the outside edge of the nostrils. Carve a pair of foam blocks to form the shape of the air ducts. Then glass the blocks to the inside of the hood. Finish up by breaking up the foam blocks and sanding the resulting inlets smooth. Epoxy will bond to clean aluminum quite well, so the probability of having them break away from the hood later on is pretty low.

Another approach is to make two moulds for each inlet. With the slots cut and the hood upside-down, you can make the three sides of each inlet first. Glass over thin plywood or masonite to give it the shape. That will ensure a good bond to the hood and a sharp top lip. Then finish off the bottom after the top had cured (in other words, build the shape directly instead of making a negative mould of the finish shape.)

[deano55]

what do you do about water? that looks like a straight shot for rain to go in?

[myfirstbonnie]

I clean and hose my engine quite often with no issues. I dislike a dirty engine.

Besides, it is not like I am going to take it through a mud bog. Yeah, a little rain might come in, but it would not be flooding into it.

[vogie01]

Are you thinking about doing it in the same location of the hood as the one in the picture? Would it be beneficial to have them located in another spot, say farther up the hood?

[GMC Guy]

I am not a bodyman but how about fabricating the scoops from a G8 onto your hood?

[myfirstbonnie]

I am not into the raised scoop thing. Just something simple yet effective. I don't think it would look good having them up much further on the hood. Mine might not even bee as large as those either. Just looking at getting airflow into the engine bay and have it directed / forced across the SC and maybe a deflector forcing it down the back of the motor.

[harofreak00]

You can get steel aftermarket hoods... would be easier to work with.

[00Beast]

You can get steel aftermarket hoods... would be easier to work with.

Adds a good bit of weight in the wrong place, though...

[rrounds]

Just something simple yet effective.

Yes its simple, but how do you know it will be effective?

When I was drag racing full time back in the 70's I would see hood scoops that would face forward but at speed the high pressure under the hood would force the air "out" of the hood scoop. The more air you put under the hood that did not go through the radiator the less air that "will" go through the radiator and that could cause a overheating problem. Plus the more air that has to go out the bottom of the car "will lift" your car as the speed goes up, not a good thing.

ROD
p.s. you have my number if you want to talk more.

[00Beast]

I agree with Rod. A little extra air moving over the S/C isn't really going to do a whole lot of good considering it's still bolted to that giant iron heat-pump we call an engine. Yes the wrinkle coating helps, but on a trip, it's all going to get heat-soaked anyways. That and more air under the hood will just make the front-end feel lighter at speed.

Have you ran this idea past Bill? He'd be the one to know what would and would not help.

[67goat]

I agree with others - unless you do wind tunnel testing, you'd be spending a lot of time and effort for potentially no benefit. I've done back to back tests at the strip with both open and closed scoops on a race car and saw zero difference. Unless you are directing the airflow into your engine (via the throttle body or carb) or baffling away from the engine bay correctly to cool the ambient air intake, simply having open scoops is an exercise in futulity. In the case of our engines, we have a CAI in the fenderwell, so scoops by themselves would serve zero purpose.

[01bonneSC]

Id be looking to have heat escape out the back of the hood. Like reverse what you have now. When the '64 gets done, the hood is getting lifted a little at the cowl with some washers or aluminum spacers to extract the heat.

[Gumball]

heat extracting vents, something like this set back on the hood.



this is from a 2010 mustang GT500

write up on it here http://sn95forums.com/showthread.php?38 ... actor-Hood

[01bonneSC]

^^^^ This

[deano55]

I dont think those small scoops will do a things to the front end's stability unless they are huge and fhey are not. Many cars in the past have had them and they would still have them if engines were still set up the same as far as preformance cars go.

[BonneMe]

A combination of hood scoop and fender venting could really cool the engine bay. But it is possible for underhood air to be problematic, when 2005 Mustangs started being road raced at high speed competitively they were blowing hoods off because air pressure built up so much inside the engine bay, the forces at work are pretty strong. I think making them feed an intake would be great, air blowing over the SC will help cool it, but blowing over an intercooler core could help performance more.

I'd focus aero work and fabrication more on making a flat tray or diffuser under the rear bumper, at speed it catches a lot of air creating drag, and lift...

[Adamus Prime]

I like it...

i've been scouring the earth for a "junk" G8 hood to cut to pieces for a scoop donor...

[harofreak00]

I like it...

i've been scouring the earth for a "junk" G8 hood to cut to pieces for a scoop donor...

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[Adamus Prime]

god, i love you guys...