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Whats up everyone? I'm still new to the car world and wanted to buy a cold air intake and fked up and just bought an air filter from jwt, essentially just creating a ram intake. So my question is, is it possible to make a custom tubing to force cold air up into the intake area. Also, would it make any difference? Instead of buying a new cold air intake system.
Welcome- this question has been asked a thousand times and the answer remains the same. Without retuning the ECM, any extra air being forced into the intake won't make any difference. Nissan also did an excellent job on the stock intake, designing it with a fairly straight shot from the front of the car, building it with a composite material to keep heat sink down and using an easy to check air filter system to keep clean airflow flowing. Building a DIY intake system and hoping to top all that factory R&D?
Welcome- this question has been asked a thousand times and the answer remains the same. Without retuning the ECM, any extra air being forced into the intake won't make any difference. Nissan also did an excellent job on the stock intake, designing it with a fairly straight shot from the front of the car, building it with a composite material to keep heat sink down and using an easy to check air filter system to keep clean airflow flowing. Building a DIY intake system and hoping to top all that factory R&D?
Forget it.
My mechanic buddy said the same thing more or less about the tune. I'm semi satisfied with what i bought, it sounds slightly better. But what about the difference in air temp instead of more air, that was my main objective. Is that difference worth it. By the sound of it, it seems like going out and buying an actual cold air intake kit is the way to go. I just figure it'd be cool to have my own custom touch to it.
The opening for the stock airbox draws air in from in front of the radiator. Unless you have that blocked off, it should provide an opening for "cold" air and is in a decent location, as there is no risk of drawing in water, and the air hasn't passed through the radiator so it should be "cold." There are options to put a slit in the front bumper and connect the opening, but I have yet to see anyone prove any gains from it. It's pretty much just aesthetics.
Freise is right; the OEM location provides for cooler air and protects from hydrolocking (unless you wade in- then it's your own fault). The difference in cooler air from below is negligible and trying to DIY a CAI from metal only increases the chance the intake charge gets warmer as the engine warms up.
Freise is right; the OEM location provides for cooler air and protects from hydrolocking (unless you wade in- then it's your own fault). The difference in cooler air from below is negligible and trying to DIY a CAI from metal only increases the chance the intake charge gets warmer as the engine warms up.
Unless i misunderstood you, I'm not trying to DIY a cold air intake, more so forcing cold air from between radiator and bumper up into the air intake area. The only thing between the engine and the intake is a metal heat shield.
Let's be clear: there's not much difference in the temperature in the intake charge from bottom to top of the radiator area. Certainly not enough to try a DIY routing system.
This is the factory opening. If you removed the air box, that is now an open channel to allow air into your intake area. Seal the new intake filter into this area to prevent drawing in engine bay air if that's what you are after. The irony to this is that building a box would be the most efficient way to do this... kind of like the stock box..
This is what you can do to route air past the bumper into that opening "faster." This would personally drive me nuts every time it rained, and won't produce any measurable gain in horsepower.
What dkmura said, and even if there is a significant difference between outside air and engine bay air, you lose that difference fairly quickly as it passes through the intake tube sitting above a header, through the metal throttle body and over the metal manifold connected to the heat producing engine.
Creating a true ram-air design wouldn't be beneficial because one must increase the length of the piping in the case of the Z. The shorter the piping the better. The less bends the better. The larger diameter the piping the better. The more surface area of the filter the better.
Ram air, like that on an old muscle car does produce results. A scoop on the hood forcing air into the filter will produce gains as acceleration increases. Minus a scoop on the hood to deliver air to the filter on a short-ram style intake r carberator, creating a new box and introducing positive pressure is the next best thing, this pressure having to do with aerodynamics.
I've posted on this site as well as a G and FX site about this many times. The photo's are of my FX. IAT's dramatically reduced. Pressurized short-ram intake.
Specifics are buried in y thread https://www.infinitiscene.com/thread...e-mods.230572/ starting on pg 5?
Nobody seems to notice that with the JWT setup and the heat shield installed they acually pulls air from below the filter ie the wheel well area. Forward wheel well get fed air from the bumper and the air has not passed thru the radiator.
then this also brings me to data logging, reading the temps as I’m driving. Stock, JWT and cold air systems all pull the same temp air. All pull in hot air when not moving, but the short ram will pull In hot air faster when stationary.
Unless the "heat shield" is more than that, unless it's a sealed enclosure receiving air from outside the engine bay only, then it's drawing air primarily from inside the bay. The only thing the heat shield below is good for is preventing the radiator fans from tripping up the air flow as the filter is right there. Radiant heat is a non-starter concerning the rubber and gauze filter, so a heat shield this is not, rather a "block the ****ing rad. fan air" shield, or something.
The jwt setup is a massive p.o.s. imo. My diy air box above runs at 4*-8* above ambient while driving and sloooowly creeps up at idle.
Unless the "heat shield" is more than that, unless it's a sealed enclosure receiving air from outside the engine bay only, then it's drawing air primarily from inside the bay. The only thing the heat shield below is good for is preventing the radiator fans from tripping up the air flow as the filter is right there. Radiant heat is a non-starter concerning the rubber and gauze filter, so a heat shield this is not, rather a "block the ****ing rad. fan air" shield, or something.
The jwt setup is a massive p.o.s. imo. My diy air box above runs at 4*-8* above ambient while driving and sloooowly creeps up at idle.
and plugging in and watching real time AIT proves you wrong. Done it with stock, JWT and CAI. The fun one was JWT without the heat shield, AIT was around 170 moving and up to 200 sitting still.
When moving and with the heat shield installed there is a constant supply of ambient air from the wheel well that supplies the filter and keeps the hot air away.
Not sure where you're coming from in proving me wrong. Not sure what AIT's are either.
I can watch my iat's (incoming air temp) all day long. Everything I've written above and below is absolutely accurate.
Upon acceleration, iat's went UP! Not what I thought they would do, but they went up one run after the next and this was during the winter in 30* weather. Idle bounced around without anything around my filter as in the photo above which was prior to building an air box.
My findings make perfect sense. Heat rises. The air filter just happens to be at a high point within the bay. Without a sealed enclosure, the engine is taking in mostly hot air, period. With a 95% or greater sealed enclosure, iat's went up much, much slower and stayed much lower and did not increase upon acceleration compared to no enclosure. With a 99% or better sealed enclosure, like what I have now, iat's very slowly creep up and upon acceleration drop down very quickly. All air that enters my air box comes from below the front bumper.
Either way, mine using real time data on 2 different track (Autoclub speedway and Willow Springs ) and driving around town in various temps showed same temps with the 3 intakes. Only one different was with the heat shield not used. From standing still it look roughly 7 seconds to show normal air temp ( 6 to 8 above ambient ) once moving.
My car has full plastic shielding installed, this could make a huge difference on how air is moved around the engine bay. I should do tests again with the vented hood and splitter installed, but don’t really care but I’ll do more testing with the belt driven hair dryer installed
If you're supercharged or turbocharged, proper intercooling should make up for the extreme environment your air filter is in. If I were s.c.'d, I'd go with water injection pre-compressor and call it a day.
From a standstill I believe it might take 7 seconds to get close to ambient, assuming you're not sitting at idle too long.
After my air box but before my sealed airbox and aramid iso-thermal spacer, 5 minutes at idle in 90* weather brought me to about 145* iat's and a minute of driving to drop back down to anywhere near ambient. In similar conditions and with the only change being a sealed air box, iat's are about 120* and took about 20 seconds to get to within 10* or less of ambient. Wrapped headers, cats, mid-pipes and a couple other minor "keep the bay cooler" mod's certainly don't hurt my cause either.
If you've got the bottom of your car covered in plastic, that's gonna have an effect on things, no doubt. A vented hood will certainly have a positive effect.
I almost forgot that I busted through my core support to allow air into the air filter box in a similar way as the red z above but without the access through the bumper. IIRC that did have a positive but minor effect on iat's.
07-22-2018, 11:21 AM
Air Intake
Not sure what AIT's are either. 
