quote Originally posted by FieroFERG: By hooking it to the intake manifold, how will that release the hot air? I guess I'm not understanding your concept, how would that be done???

I think you are on the wrong tack on this one. The scoop in that location will not expell air. The air wraps up over the rear bumper when you are under way and travels quite forcably forward. It then creates turbulence against the window as it competes the air spilling over the cab roof. I've done testing with ribbon strips.

The rear facing scoop will collect air and force it down on the motor when at speed.

Hope this helps.

Arn

AH HA! Page 2

[This message has been edited by Arns85GT (edited 05-30-2012).]

That would work too... My goal with the scoop is just to keep the engine bay as cool as possible whether it be by releasing air or taking air in... To me, either way works... Thats another new one for me though... I didn't realize it was actually sucked back in, that's quite interesting! And YES! I think that mopar six pack scoop looks great for not being molded on...

[This message has been edited by FieroFERG (edited 05-30-2012).]

The turbulent nature of air flow in the region behind the rear window in a Fiero makes it poor choice for the air intake to be located, its a low pressure zone, high pressure at the filter is desired to promote flow. Also, looking at the top of the STI "scoop", it protrudes further than the base, making a "shaker" style install even more impractical since it will catch as the deck-lid is raised. Personally, I think any shaker scoop that isn't a primary ducting for the engine air intake, is a pointless waste of hood jewelry, (and serves as only such "jewelry"). As a vent, It has merits, the shape would promote a low pressure area beneath the top ledge, and if the pressure under the deck-lid is high enough, flow can be promoted.

[This message has been edited by FieroWannaBe (edited 05-30-2012).]

I completely agree, that's why I'm still only tossing the idea of a shaker style with the STI scoop, because I haven't been able to figure out how to make it look good AND functional in my mind... If that makes any sense. But I do like it just mounted on top!

During a long road trip at highway speeds, I noticed the rear glass on my notch back got very hot as did the center console around the map holder. I pulled the console off and the computer and area was so hot, I couldn't keep my hand on it for more than 10 seconds. I figured this was due the dynamics of air flow over the fiero design at that speed creating a dead zone of air from the engine bay vents. I would agree that this could cause problems with air extraction from the scoop. The console and rear window on my car don't get that hot during normal stop and go driving so I wouldn't worry too much about functionality. During regular driving, I'm sure the scoop would serve the purpose of letting out hot air and helping to keep the engine bay cooler. If you were racing the car and needed the scoop to keep things cool for reliability and performance then it would be worth it to invest in something truly functional but usually at the cost of appearance. As for jewelry, I personally don't wear any but worn tastefully on a person, it can serve it's purpose of making them look good and catch someones attention. Your car doesn't benefit from a shiny smooth paint job to protect it any more than a rolled on coat of truck bed liner...but it sure makes it look better! If YOU think the scoop makes it look better, that's what you should do.

maybe try to fabricate it at the top of the carand mold it into the top back area of the roof and funnel it down to the side vents or use as an intake..that would inquire alot of fabricating though.. but it would be cool to do and than would ACTUALLY function as a SCOOP..

[This message has been edited by gmctyphoon1992 (edited 05-31-2012).]

Those rear deck scoops are always a hot topic because they really never work 100% either way. At different times and speeds they will work differently. Its true that at faster speeds the air flows forward over the deck which would blow air into the rear opening scoop. We know the bay is cooled by air coming from under the car and venting out the top openings. So blowing in would be counterproductive. Facing forward, would allow the hot rising air to escape and but it is blocked from blowing in. Now at slower speeds, like on surface streets...which is strongest the air moving forward on the deck or the air pushing out from underneath. Setting still in traffic its equal. An electric fan will exhaust the air faster when setting still or moving slowly. So in reality, no matter what scoop or what way it faces is not that relevant to cooling the engine compartment. Its really only a stying gimick. The best efficency outlet is the one the factory designed....flat louvers on the decklid because its not affectect by what direction the car is moving or how fast. At speed the air from under rises fast enough, and at slow speed it will naturally rise unobstructed fast enough. The only better system I think is some side, front facing scoops and louvers/ grills on the rear end of the car similar to what Ferrari did with the F40.

Post a pic or two please...

This is from driving down a dirt road with a wet car at about 40mph. Notice the distance of the opening from the rear.



The forward flow is pretty strong even at that speed. Of course I also have a 10" Hayden fan



with a fan management system.

I can tell you this setup cools the engine bay down very fast. I also have my exhaust pipes ceramic coated and wrapped to lower the temps. My coil is mounted on the firewall, same reason.

Arn

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And if I remember Arns, your fan blows up to suck the heat out correct ? Stopped, it would work about equal in or out, but out would still be best.

Nope, it blows down. I tried using fans to blow out the scoop and the engine would heat up more the faster I went.

With the fan blowing down, it follows the natural air flow. It is absolutely amazing how fast the engine cools with that fan blowing down. The fan runs about a minute and then shuts off. Also it cools the same whether driving fast or sitting still.

Arn

I cant understand how at speed it can cool blowing into the exit. Still or slow, yes I could. The Fiero design is made to take air in at bottom and out at the top. If your fan is blowing down (in) at speed, its blowing the hot air thats trying to exit right back into the bay. If its coming in at the bottom as designed and also coming in at the top, theres no where for the heat to escape... I dont question your real time experience, I just cant understand how its possible to cool if the heat is trapped in the bay unless something else is coming into play. Possibly the only way I can see that happening is if your fan is moving more air in than the car design is pulling in at say 60 mph. That would have to be a fast and powerful fan. If it is working that way, it could force the air out the bottom which is counter to the way the bottom of the car was designed.

Its like your home dryer vent. The heat dries the clothes and that hot air exits thru the vent. If you put a fan in the vent blowing it back in, the dryer will overheat because it cant escape.

Since you asked, this gets a big style (and style is the only reason you could want to stick this on there) fail from me.

It clutters up the clean appearance of the back deck lid and the car looks far better (to me) without it.

quote Originally posted by rogergarrison: Its like your home dryer vent. The heat dries the clothes and that hot air exits thru the vent. If you put a fan in the vent blowing it back in, the dryer will overheat because it cant escape.

Maybe only if sitting still?
The cowl effect while driving would probably pull air in his scoop and out his grilles even if he had no fan I would think. The fan just forces the cowl effect.

[This message has been edited by 2.5 (edited 05-31-2012).]

WRX scoop on mine.

quote Originally posted by rogergarrison: I cant understand how at speed it can cool blowing into the exit. Still or slow, yes I could. The Fiero design is made to take air in at bottom and out at the top. If your fan is blowing down (in) at speed, its blowing the hot air thats trying to exit right back into the bay. If its coming in at the bottom as designed and also coming in at the top, theres no where for the heat to escape... I dont question your real time experience, I just cant understand how its possible to cool if the heat is trapped in the bay unless something else is coming into play. Possibly the only way I can see that happening is if your fan is moving more air in than the car design is pulling in at say 60 mph. That would have to be a fast and powerful fan. If it is working that way, it could force the air out the bottom which is counter to the way the bottom of the car was designed. Its like your home dryer vent. The heat dries the clothes and that hot air exits thru the vent. If you put a fan in the vent blowing it back in, the dryer will overheat because it cant escape.

It's pretty simple Roger. The two vents were designed to allow pressure buildup in the engine bay to escape.

When the fan kicks on they still do that.

One of the problems with the air flow inside the engine bay is that the air comes up on each side, but not the middle. This means the top of the engine gets real hot. The downblowing from the scoop cools the center of the engine and the air pressure escapes out the vents.

When I did the ribbon tests at speed, the ribbons on the vents showed that the air came out at about 45 degrees sideways and almost flat verticaly. The air tumbling over the back of the roof, combined with the air building up running across the deck from behind ensured there was too much turbulence and air pressure for those vents to work well.

The six pack scoop redirects the air. It actually assists the vents to dispell air out the top. When I placed the fan blowing out, the force of the air at highway speed stalled the fan out. This caused a slow down in air flow to almost nothing over the engine. Exactly the stock problem. Once I reverse the fan to blow downward the force of the air coming forward across the deck naturally went with the fan sucking it. The air coming out of the vents did not have to compete with the air going into the scoop. It actually works, and works really well.

When the car is parked it works also. Hope this explains it for you

Arn

OK, I guess then you still use the stock vents by the quarter windows to allow it to escape and the fan/scoop just provide additional air going in if I understand. Your test verified that the air venting out the stock locations was because the air coming in the bottom tended to go up the sides right ? I can understand it then if this is the way air does move under the decklid. Id never seen anything to say that it spread to the sides before this. I just figured it went in all over the bottom, filled the bay and went out the vents as the point of least resistance. I wonder what would happen if the stock vents were blocked off.......fan in or out? You might have just changed my way of thinking on it.

[This message has been edited by rogergarrison (edited 05-31-2012).]

I never even thought about doin that... That's awesome!!!

The fans in the center of the decklid is a big mr2 swap and all those guys have them flowing downward also as arn said it does.help "push" the heat from the center out the factory vents.

So here's my question then... With my mecham side scoops, once I put the rear deck lid scoop is that gonna be kinda like crossing itself out? I mean with the scoop it draws air in at high speeds and also the side scoops are drawing air in so where's the air gonna go? Maybe I'm over thinking it or I missed something but I figured I'd just ask...

[This message has been edited by FieroFERG (edited 06-01-2012).]

Apparently you can put as much air in as you want and it all still comes out the decklid vents by the quarter panels.