BrazilBoy Posted October 27, 2008 Report Share Posted October 27, 2008 (edited) Ok heres my idea I want to put a 300zx scoop just behind my turbo to cool the exhaust side. I have a 19c, dp, and full hks exhaust. I believe getting some air to blow down there would keep under hood temps under check plus increase turbo longevity. http://www3.telus.net/Denis/pictures/300zpage/highfront.jpg OR Maybe do a EVO mesh vent. I had an EVO it snowed on turbo rained etc no worries and it didn't feel like an oven evrytime I opened the hood like my quest. Just so you know I am not putting the whole evo vent but put half of it over the turbo. http://www.evolution-8.com/images/myevo/hood-shine.jpg OR 924 carrera gt http://www.allporscheracing.com/Auto_s/924GT.jpg Edited October 27, 2008 by BRAZILBOY Link to comment Share on other sites More sharing options...
Scotty Dont Posted October 27, 2008 Report Share Posted October 27, 2008 put it over the air filter RAM AIR FTW! Link to comment Share on other sites More sharing options...
Zack_Morris Posted October 27, 2008 Report Share Posted October 27, 2008 porsche is my vote Link to comment Share on other sites More sharing options...
patra_is_here Posted October 27, 2008 Report Share Posted October 27, 2008 good luck getting one of those porsche vents. the 300zx is your best bet IMHO Link to comment Share on other sites More sharing options...
BrazilBoy Posted October 27, 2008 Author Report Share Posted October 27, 2008 http://cgi.ebay.co.uk/ws/eBayISAPI.dll?Vie...em=350106357479 Look what I just found....... Link to comment Share on other sites More sharing options...
psu_Crash Posted October 27, 2008 Report Share Posted October 27, 2008 I think it's a great idea with either scoop! I do like the 924 better though Link to comment Share on other sites More sharing options...
Fanta Posted October 27, 2008 Report Share Posted October 27, 2008 land_rocket did the 300zx scoop http://www.26liter.us/gallery/albums/userpics/10105/05_1.JPG Link to comment Share on other sites More sharing options...
BrazilBoy Posted October 27, 2008 Author Report Share Posted October 27, 2008 Looks good but will it work backwords like that? Link to comment Share on other sites More sharing options...
Fanta Posted October 27, 2008 Report Share Posted October 27, 2008 Looks good but will it work backwords like that? forward rams air in backwards, air rushing over the scoop creates a pocket of vacuum at the entrance, therefore it pulls the hot air out of the engine bay Link to comment Share on other sites More sharing options...
89PalermoSHP Posted October 27, 2008 Report Share Posted October 27, 2008 I photochopped this a while back, cant decide yea or neigh. It would be much more work than just adding a vent. http://i177.photobucket.com/albums/w202/89PalermoSHP/hood-1.jpg Link to comment Share on other sites More sharing options...
Fanta Posted October 27, 2008 Report Share Posted October 27, 2008 I photochopped this a while back, cant decide yea or neigh. It would be much more work than just adding a vent. http://i177.photobucket.com/albums/w202/89PalermoSHP/hood-1.jpg I'll be honest. I said ew. Link to comment Share on other sites More sharing options...
Scotty Dont Posted October 27, 2008 Report Share Posted October 27, 2008 looks goo to me Link to comment Share on other sites More sharing options...
JustPaus_88TSi Posted October 27, 2008 Report Share Posted October 27, 2008 forward rams air in backwards, air rushing over the scoop creates a pocket of vacuum at the entrance, therefore it pulls the hot air out of the engine bay Correct in theory, but the farther back on the hood you go, the greater chances of sucking air in. A meduim lip before a vent will create a low pressure zone behind it(the vent), but it really boils down to how much pressure is in the engine compartment below the vent. If it's easier for the air that comes into the engine compartment(through the header panel area) to be exhausted under the car, then there won't be enough positive pressure to make an exhaustive vent(on the hood) fujnction properly. I've tested our cars with a manometer and a magnehelic gauge before. If you search for those two words and my screen name, you'll find a couple posts that I went into detail with. I've tested a friends car before, and found out his "hood scoop" actually let air escape and not get sucked in. lol Link to comment Share on other sites More sharing options...
BrazilBoy Posted October 28, 2008 Author Report Share Posted October 28, 2008 I've tested a friends car before, and found out his "hood scoop" actually let air escape and not get sucked in. lol Very interesting so a scoop could make it hotter in that area. Would this also increase more under hood turbulance? In your opinion would a simple vent or louver be a more functional solution? Or perhaps a combo solution such as louvers over the turbo and an opening in the valance between the headlights? I was also thinking of putting a scoop just ahead of the turbo then louvers behind it so this should draw cool air in over the turbo then hot air out right? Link to comment Share on other sites More sharing options...
mikec Posted October 30, 2008 Report Share Posted October 30, 2008 To add to what JustPaus_88TSi said... where you put the scoop can make a big difference too. Notice on drag race cars the giant scoops are raised several inches above the hood? Some of that is simply because the motor is so tall... but if you look closely you'll see the scoop itself also has a section to lift it higher yet. Why? Because air flowing over the nose of a car is horribly disturbed. And the further back you go, the thicker the "boundary layer" on the hood will be. Ever watch a fast flowing stream/river? Notice the flow at the riverbanks is nearly stagnant? That's "boundary layer" - basically the water feels drag as it flows past the shoreline causing the water at the shoreline to slow down. This slow shoreline water then slows down the water that's just a little further away from the shoreline... over and over. If you could measure the water speed from one shoreline, across the river, all the way to the other shoreline you'd find it's roughly parabolic: zero at the shorelines and building to a maximum near the river center. (assuming a constant water depth river, etc) Air flowing over the hood is also slowed down. As you work your way back from the nose of the car, this slowed-down boundary layer gets thicker and thicker. That Porsche scoop has a little "rise" to it to get above this boundary layer. Also, whenever air has to accelerate to get around something (i.e. it has to move out of the way when the nose of the car slams into it) the air pressure drops. There is a big pressure drop on a car right at the bodywork fold/crease between the header panel and hood. However, where the air is first "slammed" by the car, there will be a pressure buildup: on the nose of the car or at the base of the windshield. This big pressure is what accelerates the air; as the air speeds up the pressure drops. Then when the air changes direction suddenly that causes big pressure changes - usually drops in pressure. Until the air slams into something else like the windshield, then there will be a pressure buildup again. The top of the windshield/roof junction will have another pressure drop. Notice many race cars (NASCAR, and many high-perf street cars) had scoops that faced the windshield? The air intakes for the dash vents/air conditioner on a StarQuest are in that black grill at the base of the windshield. They try to inhale the pressure buildup caused by the windshield. Get too far away from the windshield and you'll miss the pressure... get too close though and the scoop itself deflects the air instead of the windshield deflecting it. That's why car manufacturers, racers, etc. spend time in the wind tunnel. mike c. Link to comment Share on other sites More sharing options...
Truth Posted October 31, 2008 Report Share Posted October 31, 2008 Mike is the smartest man i've ever met, and i haven't even met him. Great explanation! Link to comment Share on other sites More sharing options...
BrazilBoy Posted October 31, 2008 Author Report Share Posted October 31, 2008 To add to what JustPaus_88TSi said... where you put the scoop can make a big difference too. Notice on drag race cars the giant scoops are raised several inches above the hood? Some of that is simply because the motor is so tall... but if you look closely you'll see the scoop itself also has a section to lift it higher yet. Why? Because air flowing over the nose of a car is horribly disturbed. And the further back you go, the thicker the "boundary layer" on the hood will be. Ever watch a fast flowing stream/river? Notice the flow at the riverbanks is nearly stagnant? That's "boundary layer" - basically the water feels drag as it flows past the shoreline causing the water at the shoreline to slow down. This slow shoreline water then slows down the water that's just a little further away from the shoreline... over and over. If you could measure the water speed from one shoreline, across the river, all the way to the other shoreline you'd find it's roughly parabolic: zero at the shorelines and building to a maximum near the river center. (assuming a constant water depth river, etc) Air flowing over the hood is also slowed down. As you work your way back from the nose of the car, this slowed-down boundary layer gets thicker and thicker. That Porsche scoop has a little "rise" to it to get above this boundary layer. Also, whenever air has to accelerate to get around something (i.e. it has to move out of the way when the nose of the car slams into it) the air pressure drops. There is a big pressure drop on a car right at the bodywork fold/crease between the header panel and hood. However, where the air is first "slammed" by the car, there will be a pressure buildup: on the nose of the car or at the base of the windshield. This big pressure is what accelerates the air; as the air speeds up the pressure drops. Then when the air changes direction suddenly that causes big pressure changes - usually drops in pressure. Until the air slams into something else like the windshield, then there will be a pressure buildup again. The top of the windshield/roof junction will have another pressure drop. Notice many race cars (NASCAR, and many high-perf street cars) had scoops that faced the windshield? The air intakes for the dash vents/air conditioner on a StarQuest are in that black grill at the base of the windshield. They try to inhale the pressure buildup caused by the windshield. Get too far away from the windshield and you'll miss the pressure... get too close though and the scoop itself deflects the air instead of the windshield deflecting it. That's why car manufacturers, racers, etc. spend time in the wind tunnel. mike c. So 924 scoop or no scoop? Thanks for the great info by the way, well said sir, well said indeed. Link to comment Share on other sites More sharing options...
mikec Posted October 31, 2008 Report Share Posted October 31, 2008 Here's a trick I suggested to a buddy of mine that used to run the SCTA (Southern California Timing Association) speed events - the SoCal club that does Bonneville style high-speed runs in the local deserts: They wanted to put an engine air inlet scoop on the "Salty Cuda" (a Plymouth Baracuda that races on the Salt Flats) to absorb the high pressure at the base of the windshield and feed that to the carb - a way to get a couple psi of free "boost pressure." But how to optimally place it? On aircraft, we sometimes flight test with "strip-a-tube" so I suggested they do a much cheaper clone of strip-a-tube... just tape thin vac hose to the hood. Plug the very END of a vac hose by pinching it shut and using heat or glue to hold it that way. Ideally you will get it to look like a chisel or screwdriver end - i.e. not a blunt end of a cylinder but a nice aerodynamic wedge. About an inch from this end, make a small hole (1/16th inch or so) in what will become the top of the hose - like the mouthpiece area of a flute. This is the pressure sensing end. Now tape this hose to the hood of the car, running the hose longitudinally: wedge forward, rest of hose going STRAIGHT BACK towards the windshield at least 6 inches before it bends to go into the passenger side window. Keep the tape as "clean" and flat to the car as possible - no lumps in the tape. Hook the other end of the hose to a small vacuum/pressure guage that your passenger can hold & read. Put several such tubes on the car - each "sampling" a different area of the hood. Put them about half in apart (side to side) from each other, and make the sensing holes about 2 inches apart front-to-back. With several hoses, you can "sample" a large area of the hood this way. Number the hoses though so you can use one pressure guage, hooked to each hose in turn, to record the data. Go for a drive on a long, straight road, hopefully one out in the middle of nowhere so there's no other traffic to distort the air and nothing for you to hit when you lean over and eyeball the pressure readings yourself! As you drive at a STEADY speed, have your passenger move the guage from hose to hose and write down the pressure readings. Then go about 5 to 10 MPH faster and re-read everything. Repeat for lots of speeds. Back home, load the pressures, MPH, and hose number into Excel or whatever and make a surface plot. Find the highest pressure regions. You could probably do this under the hood too, using metal piping attached to the hood (using aluminum tape, not regular tape) over the hot area of the turbo, then somewhere away from the turbo heat you'd switch over to regular vac hose. Now you can see if there is vacuum or pressure in the area of the turbo that you want to cool down. If there is more pressure here than above the hood, your scoop will exhaust air from the engine bay rather than force fresh cool air into the engine bay. mike c. Link to comment Share on other sites More sharing options...
zactek Posted October 31, 2008 Report Share Posted October 31, 2008 Here are my vents, located where air gets sucked out from under the hood, and the outside elements don't affect much under the hood in that area http://img210.imageshack.us/img210/4156/rebuildpics078fv9.jpg Zack Link to comment Share on other sites More sharing options...
travs87tsi Posted October 31, 2008 Report Share Posted October 31, 2008 are your center caps photochopped that color? Link to comment Share on other sites More sharing options...
BrazilBoy Posted October 31, 2008 Author Report Share Posted October 31, 2008 Here are my vents, located where air gets sucked out from under the hood, and the outside elements don't affect much under the hood in that area http://img210.imageshack.us/img210/4156/rebuildpics078fv9.jpg Zack Wow looks sharp, I like the vents, got a close up of it? By the way thats one sharp flatty you got there very nice. Link to comment Share on other sites More sharing options...
silkdagger05 Posted October 31, 2008 Report Share Posted October 31, 2008 (edited) what about the "turbo" hood that some sqc'ers talk about isn't that one designed to help the car with what we want ? Edited October 31, 2008 by silkdagger05 Link to comment Share on other sites More sharing options...
D_Venable Posted October 31, 2008 Report Share Posted October 31, 2008 this "turbo" hood is the 83 model year hood. Every year had a turbo hood in reality. the 83 hood's scoop and vents are fake/solid, but they can be opened up. but they are NOT in the ideal positions to scoop and vent air Link to comment Share on other sites More sharing options...
zactek Posted November 1, 2008 Report Share Posted November 1, 2008 Wow looks sharp, I like the vents, got a close up of it? By the way thats one sharp flatty you got there very nice. Thanks for the compliment, it's a work in progress......I'll try to get some close-ups.. Zack Link to comment Share on other sites More sharing options...
shift1313 Posted November 3, 2008 Report Share Posted November 3, 2008 are your center caps photochopped that color? other pics of zacks car have the red center caps. im going to guess the flash made them "pop" like that. Link to comment Share on other sites More sharing options...
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