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Old 07-24-2014, 12:06 AM   #1
vicious_fishes
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Default let's talk hood vents/scoop deletes: now with louver discussion

in the OEM location.

there's the KS tech ones like this:



which can also come with louver system like this:


(it goes under the mesh)

there's the first seibon like this:



the chargespeed like this:



and then another seibon one like this (can't hotlink images):

http://www.importimageracing.com/sei...-pd-style.html



for those in the know... which one is "best"?
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Last edited by vicious_fishes; 07-28-2014 at 04:17 AM.
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Old 07-24-2014, 01:07 AM   #2
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Isn't it all just personal preference ?
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Old 07-24-2014, 02:57 AM   #3
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be nice if someone did under hood temp comparisons
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Old 07-24-2014, 06:56 AM   #4
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Quote:
Originally Posted by raggedoutsti View Post
be nice if someone did under hood temp comparisons
Underhood pressure comparisons is what you'd really want to see.
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Old 07-24-2014, 09:45 AM   #5
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those alternate scoops would seem to draw air out. The purpose of the OEM scoop is to pull air into the TMIC.

It you look at the Seibon, there is no IC there.

So I'm assuming you no longer have the TMIC?
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Old 07-24-2014, 10:27 AM   #6
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nope.
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Old 07-24-2014, 11:52 AM   #7
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The blue seibon one looks good. You want that little winglet up front to create an area of low pressure to help draw air out of the engine bay.

The first one - KC thing - looks like it's just a screen and wouldn't do much to pull the air out of the engine bay. Even with the optional louver thing (esp if it its UNDER the mesh)

There are probably better places to locate the 'scoop' but since the hole is already there, might as well use it.
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Old 07-24-2014, 02:20 PM   #8
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We use the one in the picture below. We actually still found it may be necessary to add a small piece of angle at the peak of the lip (above Agile Auto Sticker) to assist in drawing the air out better (like Tim_ said). There is very limited space for the air to go under the car due to the aero we have under there. Honestly i don't think the vents along the side have enough of a lip to create the pressure to draw air out of them.....

In response to RaggedoutSti..... We have not done comparisons on under hood temps but as the driver i can tell you that the scoop delete is very beneficial in a few ways. First we don't need to be scientists to tell the OEM scoops are parachutes. If you are not TMIC then your are only causing turbulence in the engine bay and not allowing any organized air removal. I personally have also noticed that the scoops main goal is to rip your hood off . There have been times at high speeds where i have watched the scoop pulling the entire hood up. The reverse scoop does the opposite, Although it still lacks the complete ability to achieve the organized 'draw' of air from the engine bay it is 20 steps in the right direction. We are adding a small lip/angle to the reverse scoop and i will report back our findings. Recently we have been trying to combat under hood temps several different and I will also share any victories we have as well.

Throwing this out there though I think it is obvious. There is a minor increase in top speed when the drag of a scoop is removed or minimized.


-Dan




Last edited by FjStix; 07-24-2014 at 02:33 PM.
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Old 07-24-2014, 04:07 PM   #9
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fwiw the TIC guys had great success with a pair of louvers running down either side instead of the holes your CF hood has fjstix. though the low pressure of the hood is at the front so i'd say the holes are doing plenty.
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Old 07-25-2014, 02:30 PM   #10
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Quote:
Originally Posted by vicious_fishes View Post
fwiw the TIC guys had great success with a pair of louvers running down either side instead of the holes your CF hood has fjstix. though the low pressure of the hood is at the front so i'd say the holes are doing plenty.
Exactly! Where the factory scoops sit is by the high pressure area by your cowling (also why you oem blower pulls from there).
Look at WRC cars, Lemans, etc...you pull from low pressure/high velocity areas to evacuate.
We did similarly on the oil cooler for the TIC car. Small naca in, to a proper duct and the air coming around the bumper pulls off a lip and all of this is just in front of the passenger wheel.
Very simple concepts.

The rear radiator ducting took some actual nerd work but works flawlessly and we could reduce drag if the mold for the outlet duct ever gets laid up (some 2+ years later)
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Old 07-26-2014, 12:12 AM   #11
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Exactly! Where the factory scoops sit is by the high pressure area by your cowling (also why you oem blower pulls from there).
Look at WRC cars, Lemans, etc...you pull from low pressure/high velocity areas to evacuate.
We did similarly on the oil cooler for the TIC car. Small naca in, to a proper duct and the air coming around the bumper pulls off a lip and all of this is just in front of the passenger wheel.
Very simple concepts.

The rear radiator ducting took some actual nerd work but works flawlessly and we could reduce drag if the mold for the outlet duct ever gets laid up (some 2+ years later)
yep. the question is basically whether there's a hood vent design that allows it to be used as a vent/makes some low pressure where it's needed or not.

i plan on (also) running louvers like the TIC car and also some louvers out the top of the wheel fenders. i was originally thinking these fenders:

http://www.vividracing.com/catalog/s...5-p-11709.html

(though they make a frp set that are a lot cheaper iirc) but the air only exits horizontally there, not vertically. and just bolting a pair of louvers on is a lot cheaper.

that way a flat bottoming/"sealing" off of the bottom of the engine bay would result in ALL air flowing out vertically. it's still a ways off yet (need to buy voltex bumper) but i'm getting closer
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Old 07-27-2014, 12:16 AM   #12
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Racing on a budget!





This was my solution that is still evolving and I plan to do louvers on the sides as well. This was a quick fix at Sebring at the end of last season. Since going front mount the hood scoop was not doing me any favors and I have been having trouble keeping temps in check. Temps are now much more stable with this plate installed vs hood scoop. Car also seems a little smoother at speed without my hoodscoop lifting my hood on long straights.


This is what I'm ultimately shooting for. *Not my photo nor did I take obviously*


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Old 07-27-2014, 01:46 PM   #13
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that one's probably actually flowing air in dude. the area around the wipers is a HIGH pressure area would you believe.
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Old 07-27-2014, 05:33 PM   #14
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that one's probably actually flowing air in dude. the area around the wipers is a HIGH pressure area would you believe.
I believe it! You think it might be more effective with out the lip/vent in the back then? Maybe just flat like the last picture, with the addition of side louvers? So what your saying is right now I am essentially still pressurizing the engine compartment and this is acting similar to a muscle car with a cowl induction hood? Maybe tape some streamers, as a test, all along the exit of the vent and see if its trying to pull them into the engine bay, if it is indeed a high pressure zone where the vent exits against the cowl? This car obviously will not be seeing a wind tunnel anytime soon haha

Last edited by blazzin06wrxdude; 07-27-2014 at 05:43 PM.
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Old 07-28-2014, 02:10 AM   #15
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I believe it! You think it might be more effective with out the lip/vent in the back then? Maybe just flat like the last picture, with the addition of side louvers? So what your saying is right now I am essentially still pressurizing the engine compartment and this is acting similar to a muscle car with a cowl induction hood? Maybe tape some streamers, as a test, all along the exit of the vent and see if its trying to pull them into the engine bay, if it is indeed a high pressure zone where the vent exits against the cowl? This car obviously will not be seeing a wind tunnel anytime soon haha
yep. and streamers aren't so good because they're shaped. try some cutoffs of cotton/wool. they'll go everywhere

basically with the hood the further forward you go, the lower pressure and therefore better venting you'll get. it's just a question of whether we can use the hood scoop area/if it's far enough forward to become a vent. when i taped some paper over the lip of mine (i have that blue seibon one posted) they seemed to be pushed up and not in, but a tad tubulent-ly.

also a front lip does wonders for aero lift as well as cooling
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Old 07-28-2014, 04:18 AM   #16
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on a related note, sealing off the fenders from the engine bay/louvers on them...

i was thinking i could seal the fenders off, OR... i could leave them open and run some side louvers along the side to allow air to vent from the engine bay, to the fenders and then out the top/side of said fenders.

which way should i go about things? seal them off or use them for venting?

edit: tic have vents there for "aerodynamic purposes", hmmm...

Last edited by vicious_fishes; 07-28-2014 at 10:26 AM.
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Old 07-29-2014, 12:33 PM   #17
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This is probably a picture that will give you the best idea of the hood vents that we have on the car. We vent the fenders too but that's a different story.

Also, hard to see in this pic, is that the lower passenger side naca duct feeds the oil cooler that dumps out the side of the bumper, in front of the wheel.

Easier to see in the banner here:
https://www.facebook.com/pages/3MI-R..._type=bookmark
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Old 07-29-2014, 01:01 PM   #18
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already have you on facebook micah! :P

what i can see from that pic is exactly how i plan on running things. i'll start with the side louvers and do some more wool testing of the reverse scoop vent thing with the big lip on the front of it.

more curious about sealing off the fenders from the engine bay vs opening them up and running louvers out of them like you have. obviously you've got the louvers there for a different purpose (i've seen them on a fair few other race cars as well) but that doesn't necessarily mean what i'm suggesting won't work either. it's just a question of whether it's *actually* a good idea or not. doesn't take anything to holesaw a couple holes near the fusebox or go the other way and seal the airbox holes off on the right hand side.
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Old 07-30-2014, 12:39 PM   #19
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Nashua aluminum tape is your friend
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Old 07-30-2014, 12:58 PM   #20
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awesome. thanks mate.
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Old 08-19-2014, 01:35 AM   #21
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alright just did the tape & wool test. air flows INTO scoop replacing "vents". no matter how i taped the wool (front or back) it always remained stubbornly pushed into the engine bay. myth busted.
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Old 08-19-2014, 02:07 AM   #22
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if you want heat to come out your hood, closest to the windshield L & R side is the best spot. cut a square add flipper to make it direct the air up so it will draw air out... you can see in the picture the L shape flippers you need to make or buy




center of the hood is only good to push air in ! reverse scoop dont work at all.
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Old 08-19-2014, 09:45 AM   #23
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well no that's not true, it's the back of the hood that is high pressure. as long as you're at the front, you'll get ventilation. the vents are typically mounted on the side so that when it rains, water doesn't get on the engine, alternator etc etc.
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Old 08-19-2014, 09:45 PM   #24
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alright just did the tape & wool test. air flows INTO scoop replacing "vents". no matter how i taped the wool (front or back) it always remained stubbornly pushed into the engine bay. myth busted.
It was never a myth, just physics. Glad you got the positive comformation for your setup.

Quote:
Originally Posted by NICO TURBINE View Post
if you want heat to come out your hood, closest to the windshield L & R side is the best spot. cut a square add flipper to make it direct the air up so it will draw air out... you can see in the picture the L shape flippers you need to make or buy

center of the hood is only good to push air in ! reverse scoop dont work at all.
Though it works on that application, it won't work on all applications. You'll notice the car has a high center (with high pressure area from the scoop) and sloping shoulders, giving high velocity and low pressure as the air 'rolls' off the sides of the hood.

So something like a GC with a more flat hood would need the same items pushed further outward and/or forward as the high pressure area is larger...sure enough, look at the WRC cars of the era and the 22B.
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Old 08-20-2014, 12:14 AM   #25
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Quote:
Originally Posted by Homemade WRX View Post

Though it works on that application, it won't work on all applications. You'll notice the car has a high center (with high pressure area from the scoop) and sloping shoulders, giving high velocity and low pressure as the air 'rolls' off the sides of the hood.

So something like a GC with a more flat hood would need the same items pushed further outward and/or forward as the high pressure area is larger...sure enough, look at the WRC cars of the era and the 22B.

never thought of it like that, I better do a test on my car before I start cutting.. i have a very flat style hood and small shoulders..

they updated there cars for 2014 to even more vents and forward..

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