Anyone using a LARGE NACA duct air intake?
#32
Well i havent done a before and after dyno....but i know it can only help matters (in terms of power)....it has been strategically placed to give a direct flow of cold air to the Air filter of my single turbo.......so no hot air for me!!!!
#33
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Thanks for the pics. your hood looks pretty good. do you have a pfc or something to monitor air intake temp? what are your hottest intake temps if you sit in traffic on the hottest days? Did you notice if your temps were cooler? I see you have a front mount IC. please post a pic of your air filter area under your hood, and go ahead show off other engine pics.
#34
Yes i have a pfc.......air intake temps...in traffic are around 40-45c....but this nothing to do with my bonnet duct...as this only comes into play once moving.....as its sole purpose is to feed cooler air to the turbo/filter when on the move under boost.
#35
Please somebody help!!!
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any way you could do a vs test for us?
Cap off your duct drive around for 10 miles or so then do a redline pull. log temps.
uncap your duct drive around for 10 miles or so (same place, speed, etc.) then do a redline pull (same gear, same place, etc). log temps.
#36
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Is the 40-45 the highest you've seen? If you think about it, this summer post some numbers. I'm still interested in pics of your intakes and motor.
I use to have a spitfire, it had a bonnet.
#37
If anyone is thinking of doing this to a track driven car, pretty much anywhere on the hood is a bad idea for a NACA duct to bring in air. If you are only using it to bring cool air into the engine bay or evacuate heat, that's ok, but not if you are going to duct air directly to a sealed turbo inlet. Actually, it's ok to about 100 mph, after that's it's not a good idea. Does look cool though.
#40
i have a single.
#41
#42
right, but even when you're sitting still your engine is ingesting air, not as much, but air none-the-less.
any way you could do a vs test for us?
Cap off your duct drive around for 10 miles or so then do a redline pull. log temps.
uncap your duct drive around for 10 miles or so (same place, speed, etc.) then do a redline pull (same gear, same place, etc). log temps.
any way you could do a vs test for us?
Cap off your duct drive around for 10 miles or so then do a redline pull. log temps.
uncap your duct drive around for 10 miles or so (same place, speed, etc.) then do a redline pull (same gear, same place, etc). log temps.
sorry bud..i dont have time to do this at the moment.....when i do i'll let you know.
#43
NACA ducts are primarily for use in areas of low pressure or a very thin boundry layer of air. At higher speeds, the air stream over the nose of an FD (and most cars) arcs up over the hood enough to cause a vacuum in most places on the hood. Once there is a vacuum, there is no air available to enter the duct. In fact, the under hood pressure caused by air entering the nose creates such a high pressure differential between the topside and bottomside of the hood that air will start to exit the duct instead of enter. This is why NACA ducts or any reverse duct works great for evacuating heat from under the hood. I actually tried running 2 NACA ducts on my hood when i still had stock twins with 3" hoses directly feeding the turbo inlets. After about 95 mph, the boost would drop to about 5 pounds or less and fluctuate a lot. At this speed, there was no air available at the surface of the hood for the turbo to suck in. At low speeds, the duct "could" work, but given the high underhood pressure caused by most aftermarket bumpers, it's doubtful it's doing it's job.
#44
2/4 wheel cornering fiend
In fact, the under hood pressure caused by air entering the nose creates such a high pressure differential between the topside and bottomside of the hood that air will start to exit the duct instead of enter. This is why NACA ducts or any reverse duct works great for evacuating heat from under the hood.
#45
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NACA ducts are primarily for use in areas of low pressure or a very thin boundry layer of air. At higher speeds, the air stream over the nose of an FD (and most cars) arcs up over the hood enough to cause a vacuum in most places on the hood. Once there is a vacuum, there is no air available to enter the duct. In fact, the under hood pressure caused by air entering the nose creates such a high pressure differential between the topside and bottomside of the hood that air will start to exit the duct instead of enter. This is why NACA ducts or any reverse duct works great for evacuating heat from under the hood. I actually tried running 2 NACA ducts on my hood when i still had stock twins with 3" hoses directly feeding the turbo inlets. After about 95 mph, the boost would drop to about 5 pounds or less and fluctuate a lot. At this speed, there was no air available at the surface of the hood for the turbo to suck in. At low speeds, the duct "could" work, but given the high underhood pressure caused by most aftermarket bumpers, it's doubtful it's doing it's job.
#46
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[QUOTE=Synaptic 3;7880994]NACA ducts are primarily for use in areas of low pressure or a very thin boundry layer of air. At higher speeds, the air stream over the nose of an FD (and most cars) arcs up over the hood enough to cause a vacuum in most places on the hood. Once there is a vacuum, there is no air available to enter the duct. In fact, the under hood pressure caused by air entering the nose creates such a high pressure differential between the topside and bottomside of the hood that air will start to exit the duct instead of enter.
Interesting...... Try taping some yarn/tread/strips of paper in front of the duct and see if this is true. I thought at those speeds air would be forced in any openings in front of the car
Interesting...... Try taping some yarn/tread/strips of paper in front of the duct and see if this is true. I thought at those speeds air would be forced in any openings in front of the car
#47
2/4 wheel cornering fiend
I actually tried running 2 NACA ducts on my hood when i still had stock twins with 3" hoses directly feeding the turbo inlets. After about 95 mph, the boost would drop to about 5 pounds or less and fluctuate a lot. At this speed, there was no air available at the surface of the hood for the turbo to suck in.
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