hood scoops what do you think?

[signgrafix]

What do you guys think about installing a cowl induction hood scoop for cool air induction? Of course you would need the scoop come all the way back down to where your air filter is located. Do they make these hood especially for diesels? Sounds to me it would be a good idea especially for those that do a lot of highway miles and towing. Whad da ya think?

[JoeyD]

Functioal cowl induction is a good idea. Another idea is a vent on the rear of the front fender to allow air to escape from under the hood while the truck is moving.

[Hubert]

Yeah its a good idea. Under hood temps can be brutal. Mark Rinker once posted this website

http://www.goodmarkindustries.com

I have been dreaming of buying these items ever since:

1) Functional cowl hood.
2) Front Bumper with a big "catfish mouth" hole in it instead of the (2) OE diesel holes.
3) Front bumper air dam.
4) Fender (s) with vents. Not sure if passenger side vent would help or hurt air flow to intake though?

The cowl hood coupled with a "AFE cold air intake box" or similar I think would really make the turbo sound sweeeeeet too.

[DmaxMaverick]

A couple things to remember if you intend to force more air into the engine compartment and/or using an induction (cowl) hood:

Negative pressure in the engine compartment is NECESSARY! Without it, the fan will not work efficiently, and you'll have a heat trap, in effect. If you force more air in, there has to be a method of getting at least that much air out.

Aerodynamics are key. You will get different effects, at different speeds. If you have heat issues at specific speeds, you need to design/apply a system that will not compromise an already weak area. It's not likely you'll improve all areas. It can greatly effect how the vehicle handles. Too much air under a vehicle isn't a good thing. Just ask any NASCAR driver. It's not likely you "fly" off the road, but it can surely effect stability on slick surfaces at speed.

Any changes made to the airflow, regardless of where it actually ends up, will have an effect on the previous airflow characteristic. Taking air in at one point, will take it away from another point. Disrupting the airflow over the hood will have an effect on how well your wipers work, as well as how your HVAC intake gets fresh air, and what happens when you open the window at speed (among other things). You don't want to exaust engine compartment air into your HVAC intake.

[signgrafix]

Functioal cowl induction is a good idea. Another idea is a vent on the rear of the front fender to allow air to escape from under the hood while the truck is moving.

Where are we talking about on these vents? Does anybody have any pictures of where it was done?

[More Power]

What DM said, plus.....

Air moves through your A/C condenser, radiator & intercooler package because of a positive pressure in front and a negative pressure behind. Bringing more air into the engine compartment another way will reduce the pressure differential across the IC/rad/condenser package, possibly reducing the airflow through the grille package. Whether cowl induction or scoops, best results occur when used to channel air to the airbox.

Scoops might not be a good idea for use as a source for the airbox due to the airflow paths over the grille and hood. The center part of the hood actually sees a negative air pressure at highway speeds (this would suck air out of a scoop, rather than force air in).

Jim

[Hubert]

"Negative pressure in the engine compartment is NECESSARY! Without it, the fan will not work efficiently, and you'll have a heat trap, in effect. If you force more air in, there has to be a method of getting at least that much air out."

And what Jim said Absolutely, Thats why I think they all have to be incorporated.

The vents at the rear of the fender and the air dam would help create the negative pressure. I would think an aftermarket (may need to be modified) air box that attempts to seals off the cowl duct/ to air intake and the rest of the underhood would not not add too much postive pressure to the engine compartment. ???? On the bumper hole being larger. I would not think that would cause the fan to not pull air through radiator as long as the fan shroud was not changed. You could even add another small oil cooler behind the bumper or other auxillary radiator piece to add cooling. To look good I would want the grill for the hole and some sheet metal to keep air from just diverting to outside of bumper.

I was looking at the plastic OE "skid" plate that is removed to add an intercooler between the frame and wondered about how much that affects the underhood air flow. I guess the benefits of IC outweigh any added underhood pressure.

Anyone have other ways to help exhaust engine compartment air?

Dmaxmaverick I am not sure it would really affect handling at less than 85-100 mph. I have often thought empty my truck drives like you are pushing a lawn dart. Any slippery surfaces and the tail end can't be counted on to add much stopping or stability function anyway.

" Where are we talking about on these vents? Does anybody have any pictures of where it was done? "

Go the the Goodmark website I linked and look through the parts availiable for GM trucks 90's body style. They have a picture of a fender with a vent at the back. I am not sure its truely functional but looks so and/or could be modified to be functional. And they have pictures on a functional ducted cowl hood.

[signgrafix]

What DM said, plus.....

The center part of the hood actually sees a negative air pressure at highway speeds (this would suck air out of a scoop, rather than force air in).

Jim
I believe the way a cowl induction scoop works is, it gets it wind flow off the base of the windshield.

These vents, are they cut into the fender where they can be seen from the side? They would have to do a REAL GOOD job before I would want to go cutting holes in my fender.

[NH2112]

Get the hood louvered, if you do this you won't be able to hold your hand over the louvers with the engine revving because the air coming out of the louvers will be too hot.

[Kev-o]

Fenders with vents in them i don't know how functional they are. www.crosscanadaparts.com part# is 900-31p

[piersbc]

What do you all think about this? If you use a sealed AFE air intake with this hood then wouldn't it be a good setup??


http://www.stylinconcepts.com/part.aspx/partID/13793/PartFamilyID/275/SubcategoryID/347/CategoryID/25

[JeepSJ]

If we have learned anything by racing in the desert in July/August, it is how to keep air circulating through the engine compartment. From our experience...(remember, this is how to get hot air OUT of the engine compartment).

Cowl scoops - work OK at low speed, but at higher speeds they don't work due to the high pressure at the base of the windshield.

Hood louvers - work great, but if you have any fluid leaks, it makes a mess of the windshield

Hood vents - work great IF you get them in the right place. We have had the best luck placing vents along the outer edge of the hood, starting about 1/3 the way back from the front. Seems that 1/3 to 1/2 way back from the front works the best.

[garre1tt]

What kind of effect do the bug shields or brush guards have?
Michael D.

[piersbc]

My question is how does this hood keep water from entering the intake??

http://www.stylinconcepts.com/part.aspx/partID/13793/PartFamilyID/275/SubcategoryID/347/CategoryID/25

[Hubert]

Michael there was a post a while back where someone had added a brush guard on his truck and engine would run hot on the interstate.

I can't remember exactly but normal city driving I think it ran warmer but not hot. Consensus was highway speeds the air would stream up over grill and not through radiator. City driving was not fast enough to load engine or stream air up over grill and enough air would go through radiator to keep from getting too hot (but I think warm). I have heard of snow plows raised too high causing overheating.

I have never heard/read comments on bug shields vs radiator or scoop performance.

I could not open the above link.
Doesn't the street ram style scoops kind of work like a "P" trap with a built in water drain or other internal baffles that allows air to flow but doesn't allow water droplets to pass directly through. I imagine more moisture does make it to airfilter and box but its not necessarily a real bad thing unless its a lot of water. A little moisture would be like a water mist injection and make the air charge more dense. Getting engine electronics wet is another thing and or a lot of water hitting Hot manifolds etc would be trouble. But nothing is stopping water from coming through the grill now when its raining is it ???? I have kind of wondered about that sometimes. I figure the radiator shroud directs it somewhat but don't know.