RAM air set-up for the stock airbox..
11-14-2003, 08:32 AM
#41
that 2mph is very simple, you raised the temp by 30mph on stock tires, half of a race is traction, you get more of it with hotter conditions, but not too hot as to hurt performance alot. you had prime tempertures for that run.
venturi effect, as Im familiar with it, is the ide of moving air having lower pressure than stagnant. blow across a tube and air will be sucked through the tube.
perhaps another way to look at this.... what if you made that pipe HUGE!!! I mean so it filled the entire front bumper, and then all the way up and the only way out was into that airbox? ok then, we now have the stock setup. does that make sense? trying to put it clearly, unlike most cars who place their intakes IN the engine bay, our intake is outside the engine bay, sucking from that area already. meaning it already gets cold air, where would hot air come from?
venturi effect, as Im familiar with it, is the ide of moving air having lower pressure than stagnant. blow across a tube and air will be sucked through the tube.
perhaps another way to look at this.... what if you made that pipe HUGE!!! I mean so it filled the entire front bumper, and then all the way up and the only way out was into that airbox? ok then, we now have the stock setup. does that make sense? trying to put it clearly, unlike most cars who place their intakes IN the engine bay, our intake is outside the engine bay, sucking from that area already. meaning it already gets cold air, where would hot air come from?
11-14-2003, 09:05 AM
#42
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Engineering view
I am not trying to be a d*ck here, but I am an engineer so I guess I can't help it.
This setup has 2 problems that I can see.
1) It seems very likely to suck up water in a deep puddle.
2) My guess from looking at the photos is that it reduces airflow.
To elaborate on #2.
The stock airbox picks up air in fron the the radiator. It gets the same high pressure that this new intake will get.
The new intake will see approximately the same inlet pressure (within the noise margin), but it will see more turbulence. The new box also introduces a longer path length inside the pipe (drag). The pipe introduces further drag with the joints and elbows in its construction.
I would bet money that an airflow bench would show reduced airflow over the stock box. At sufficiently high speeds (very fast) you might get a little extra pressure, maybe even enough to counter the extra losses. But I think the turbulence will limit those gains.
I applaud your effort. This is not meant as an insult. Instead, I am simply saying that the stock air box is "pretty darned good". (that is an engineering term).
In the case of open element CAI systems, they may see a slight improvement because they remove path length (tubing) and the narrow opening of the pipe. That makes sense. Even those system see very small improvements. They produce much better improvements in the areas of appearance and sound.
This setup has 2 problems that I can see.
1) It seems very likely to suck up water in a deep puddle.
2) My guess from looking at the photos is that it reduces airflow.
To elaborate on #2.
The stock airbox picks up air in fron the the radiator. It gets the same high pressure that this new intake will get.
The new intake will see approximately the same inlet pressure (within the noise margin), but it will see more turbulence. The new box also introduces a longer path length inside the pipe (drag). The pipe introduces further drag with the joints and elbows in its construction.
I would bet money that an airflow bench would show reduced airflow over the stock box. At sufficiently high speeds (very fast) you might get a little extra pressure, maybe even enough to counter the extra losses. But I think the turbulence will limit those gains.
I applaud your effort. This is not meant as an insult. Instead, I am simply saying that the stock air box is "pretty darned good". (that is an engineering term).
In the case of open element CAI systems, they may see a slight improvement because they remove path length (tubing) and the narrow opening of the pipe. That makes sense. Even those system see very small improvements. They produce much better improvements in the areas of appearance and sound.
11-14-2003, 09:14 AM
#43
New Member
Ares hit it on the head.
In the stock setup the entire grill opening is your scoop. The area between the grill and the radiator is your air box (with reserve!).
Nissan was even nice enough to put a gasket between the hood and the radiator support to keep the air from going up and over the radiator.
The intake on the air box has a nice rounded shape where it flares out to the "virtual air box".
It is a thing of beauty.
In the stock setup the entire grill opening is your scoop. The area between the grill and the radiator is your air box (with reserve!).
Nissan was even nice enough to put a gasket between the hood and the radiator support to keep the air from going up and over the radiator.
The intake on the air box has a nice rounded shape where it flares out to the "virtual air box".
It is a thing of beauty.
Originally posted by ares
that 2mph is very simple, you raised the temp by 30mph on stock tires, half of a race is traction, you get more of it with hotter conditions, but not too hot as to hurt performance alot. you had prime tempertures for that run.
venturi effect, as Im familiar with it, is the ide of moving air having lower pressure than stagnant. blow across a tube and air will be sucked through the tube.
perhaps another way to look at this.... what if you made that pipe HUGE!!! I mean so it filled the entire front bumper, and then all the way up and the only way out was into that airbox? ok then, we now have the stock setup. does that make sense? trying to put it clearly, unlike most cars who place their intakes IN the engine bay, our intake is outside the engine bay, sucking from that area already. meaning it already gets cold air, where would hot air come from?
that 2mph is very simple, you raised the temp by 30mph on stock tires, half of a race is traction, you get more of it with hotter conditions, but not too hot as to hurt performance alot. you had prime tempertures for that run.
venturi effect, as Im familiar with it, is the ide of moving air having lower pressure than stagnant. blow across a tube and air will be sucked through the tube.
perhaps another way to look at this.... what if you made that pipe HUGE!!! I mean so it filled the entire front bumper, and then all the way up and the only way out was into that airbox? ok then, we now have the stock setup. does that make sense? trying to put it clearly, unlike most cars who place their intakes IN the engine bay, our intake is outside the engine bay, sucking from that area already. meaning it already gets cold air, where would hot air come from?
11-14-2003, 09:47 AM
#44
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I agree the Z set up not bad, although it doesn't appear to be designed to get any natural ram effect.
The venturi effect I was referring to is the increased pressure as air flows through a ever decreasing area. For this to be fully effective and get the most pressure increase the flow has to be relatively controlled and stay predominantly laminar. Disrupt the flow with a long tortureous path with lots of stuff to work around and the flow losses can be significant. I know you were being a bit facetious on the bumper as a air scoop idea but it would work if you could control the flow to the inlet. Of course, still need to get air flow to the radiator.
Granted the air on the current setup comes in cold, but it still has to make its way 2-3 feet through a filter, a plastic tube and some portion of the top engine housing before the combustion chambers. That entire distance is being heated by the engine and some heat transfer will heat the air above intake temp. Even though low conductive materials are used they will eventually heat up. Some good news is that the alum hood is a great heat dissipator - a downside to the CF hoods some folks are going to.
The venturi effect I was referring to is the increased pressure as air flows through a ever decreasing area. For this to be fully effective and get the most pressure increase the flow has to be relatively controlled and stay predominantly laminar. Disrupt the flow with a long tortureous path with lots of stuff to work around and the flow losses can be significant. I know you were being a bit facetious on the bumper as a air scoop idea but it would work if you could control the flow to the inlet. Of course, still need to get air flow to the radiator.
Granted the air on the current setup comes in cold, but it still has to make its way 2-3 feet through a filter, a plastic tube and some portion of the top engine housing before the combustion chambers. That entire distance is being heated by the engine and some heat transfer will heat the air above intake temp. Even though low conductive materials are used they will eventually heat up. Some good news is that the alum hood is a great heat dissipator - a downside to the CF hoods some folks are going to.
11-14-2003, 09:54 AM
#46
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Originally posted by ares
that 2mph is very simple, you raised the temp by 30mph on stock tires, half of a race is traction, you get more of it with hotter conditions, but not too hot as to hurt performance alot. you had prime tempertures for that run.
venturi effect, as Im familiar with it, is the ide of moving air having lower pressure than stagnant. blow across a tube and air will be sucked through the tube.
perhaps another way to look at this.... what if you made that pipe HUGE!!! I mean so it filled the entire front bumper, and then all the way up and the only way out was into that airbox? ok then, we now have the stock setup. does that make sense? trying to put it clearly, unlike most cars who place their intakes IN the engine bay, our intake is outside the engine bay, sucking from that area already. meaning it already gets cold air, where would hot air come from?
that 2mph is very simple, you raised the temp by 30mph on stock tires, half of a race is traction, you get more of it with hotter conditions, but not too hot as to hurt performance alot. you had prime tempertures for that run.
venturi effect, as Im familiar with it, is the ide of moving air having lower pressure than stagnant. blow across a tube and air will be sucked through the tube.
perhaps another way to look at this.... what if you made that pipe HUGE!!! I mean so it filled the entire front bumper, and then all the way up and the only way out was into that airbox? ok then, we now have the stock setup. does that make sense? trying to put it clearly, unlike most cars who place their intakes IN the engine bay, our intake is outside the engine bay, sucking from that area already. meaning it already gets cold air, where would hot air come from?
11-14-2003, 10:14 AM
#47
Originally posted by djkern
isn't that what they use the large fan in front of the car for?? or is that just to keep the car cool?? i wouldn't know...never dyno'd my car.
isn't that what they use the large fan in front of the car for?? or is that just to keep the car cool?? i wouldn't know...never dyno'd my car.
use the fan to keep the car cool, then Find the strongest Leaf blower you can find, and stick it in the Hole in the grill. instant ram air on the dyno!!!!!!!!!!!
11-14-2003, 10:14 AM
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As I understand your design you're "venturing" from a 4" diameter to a 3" dia? If this a relatively gradual change then the flow rate will increase ~ 50% over the stock setup assuming no ram effect from frontal area of the car. IMO the flow would be too disrupted to get much, if any, ram effect from the open area around the front of the car with the stock setup.
11-14-2003, 11:17 AM
#49
Originally posted by 350Z_Redline
There's just no convincing ya huh? My ET's and traps are pretty consistant. It's cool though...we'll see how my traps look once you guys get my plenum out to me 
There's just no convincing ya huh?
My ET's and traps are pretty consistant. It's cool though...we'll see how my traps look once you guys get my plenum out to me
11-14-2003, 11:30 AM
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Originally posted by VandyZ
Haha, yeah I was talking to a couple people round the shop yesterday about the +2 mph and I was shut down every time (I was trying to believe it). I dont remember the exact difference between my 1/8 mile runs with and without the plenum, but it was around .15 seconds and 2 mph. But that was between my first (ever) runs and my second (ever) runs 4 months and apart with lots more street practice and 20 degrees warmer. I dont think I could attribute all of that to just the plenum. I bet if I went back I could better my times by another .1 seconds. That would put me in the high high 8's or low low 9's (8.99-9.00)
Haha, yeah I was talking to a couple people round the shop yesterday about the +2 mph and I was shut down every time (I was trying to believe it). I dont remember the exact difference between my 1/8 mile runs with and without the plenum, but it was around .15 seconds and 2 mph. But that was between my first (ever) runs and my second (ever) runs 4 months and apart with lots more street practice and 20 degrees warmer. I dont think I could attribute all of that to just the plenum. I bet if I went back I could better my times by another .1 seconds. That would put me in the high high 8's or low low 9's (8.99-9.00)
11-14-2003, 12:08 PM
#51
Originally posted by djkern
i was like "HOLY $HIT" 8.99 - 9.00 seconds 1.4 mile. how the hell???? then i ralized it was 1.8 mile. d'oh! haha.
i was like "HOLY $HIT" 8.99 - 9.00 seconds 1.4 mile. how the hell???? then i ralized it was 1.8 mile. d'oh! haha.
I wondered if I should have put more than one "1/8" designators in there. I figured I would have to remind someone I said "1/8".
11-14-2003, 12:24 PM
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What Effect do Aftermarket Grilles Have?
Hmmmm..........all this talk about the "virtual airbox behind the grill", airflow..........stock setup is good............got me thinking.
A lot of us have put aftermarket grilles on top of or in place of the stock grill. Most of the aftermarket grilles block off a ton of what used to be open space for air to travel in to the front of the car.
If you have the stock airbox, pop charger or short ram.........won't these aftermarket grills mess with the air flow equation? i.e. allow less air to come in?
Any thoughts on this?
A lot of us have put aftermarket grilles on top of or in place of the stock grill. Most of the aftermarket grilles block off a ton of what used to be open space for air to travel in to the front of the car.
If you have the stock airbox, pop charger or short ram.........won't these aftermarket grills mess with the air flow equation? i.e. allow less air to come in?
Any thoughts on this?
11-14-2003, 12:38 PM
#54
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Originally posted by Z-*****
why not just cut a hole in the bumper or hood right in front of the airbox?
why not just cut a hole in the bumper or hood right in front of the airbox?
11-14-2003, 12:51 PM
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mate.... I like your idea... that's great!!!
If you want to further increase the amount of air that gets suck in from the front end of the car, use a funnel to attach at the front because the straight cut pipe will allow quite a lot of air turbulance around the opening.... get the funnel to create a bell mouth shape, it actually increase the amount of air gets suck in!
Just look at the E36(euro)/E46 M3's 6 throttle intakes in the airbox, you will understand what I meant!
cheers and good luck!
richie
If you want to further increase the amount of air that gets suck in from the front end of the car, use a funnel to attach at the front because the straight cut pipe will allow quite a lot of air turbulance around the opening.... get the funnel to create a bell mouth shape, it actually increase the amount of air gets suck in!
Just look at the E36(euro)/E46 M3's 6 throttle intakes in the airbox, you will understand what I meant!
cheers and good luck!
richie
11-14-2003, 01:07 PM
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that's nice that there are aftermarket bumpers that have that hole there already... there are also aftermarket intakes that have ram air as well, so that doesn't change my point.....
Everyone is complaining about bends and tubes and funnels and blah blah blah.... but what about just one opening that tunnels straight to the airbox??? wouldn't this be better?
Everyone is complaining about bends and tubes and funnels and blah blah blah.... but what about just one opening that tunnels straight to the airbox??? wouldn't this be better?
11-14-2003, 01:11 PM
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Originally posted by 35ounces
You can!
You can!
11-14-2003, 01:41 PM
#59
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Yes it might work better but its just a little too drastic for me. But hey don't let that stop YOU. Try it and let us know. If your results are really good I might be swayed
08-21-2005, 06:52 PM
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I was working on a ram air setup for my 35th aniv when I came across this old thread. I'm using the duct HERE, mounted under the aluminum bumper against the left side of the car, right where that plastic piece used to be that blocked off the left side of the grille. I am using 3" brake duct silicone hose, and made an adapter for the inlet to the air box. As soon as it's all set up I will post some pics. My question is, has anyone else tried something like this since this thread was originally started in 2003, and has there been any further work on performance testing such as a setup?