Modifying the Stock Air Intake System

[goldstar]

I'm glad cutting out the opening went well. I'll be interested in how the system responds when you remove the resonator. I'm equally interested in how a pink air intake system will look.

Happy Motoring!

[norwood1026]

Um does anyone got a picture of the map sensor? Maybe tell me how to removes it.....yes I'm an idiot...

[goldstar]

norwood1026, the MAF sensor is located between the outlet of the air box and the rubber hose that connects to the TB. The screen (or mesh) that's fitted to the air box side of the sensor has to be removed. That's what's causing the restriction. A photo of the screen and the proceedure to remove it can be found in post #2. It's a simple job but be very careful that you don't damage the MAF sensor itself. Good luck with the project.

Happy Motoring!

[norwood1026]

norwood1026, the MAF sensor is located between the outlet of the air box and the rubber hose that connects to the TB. The screen (or mesh) that's fitted to the air box side of the sensor has to be removed. That's what's causing the restriction. A photo of the screen and the proceedure to remove it can be found in post #2. It's a simple job but be very careful that you don't damage the MAF sensor itself. Good luck with the project.

Happy Motoring!

Thanks I'll give it a shot. The weather is getting hot here again.. so by the time I get home from work I'm running inside for the AC. Soon as we have a cooler day I'll pull it out. I like this mod much better then adding a CAI I never understood how people get any real HP from sucking in hot air. I personally don't drive with the hood up & a fan blowing on it...

[1Mazda323Fan]

I like this mod much better then adding a CAI I never understood how people get any real HP from sucking in hot air.

Actually, installing a true cold air intake will net you a far bigger increase in power than just removing the MAF screen. A true CAI actually does sit near the ground, away from hot engine components where the air actually is cooler. What you're thinking of is commonly referred to a short ram intake, which, while it does sit close to the hot engine components, will provide an increase in power due to the fact that it has an open element filter, which allows more air to enter than the stock, restrictive air box and its associated straw. The construction of the intake pipe on both short rams and cold airs also improve intake air flow (smooth walls make for smoother flow).

[norwood1026]

Actually, installing a true cold air intake will net you a far bigger increase in power than just removing the MAF screen. A true CAI actually does sit near the ground, away from hot engine components where the air actually is cooler. What you're thinking of is commonly referred to a short ram intake, which, while it does sit close to the hot engine components, will provide an increase in power due to the fact that it has an open element filter, which allows more air to enter than the stock, restrictive air box and its associated straw. The construction of the intake pipe on both short rams and cold airs also improve intake air flow (smooth walls make for smoother flow).

I personally do not see how air coming off the road is cooler then where the air where it is coming on on our scoops. I understand cold air is denser but the hear coming off a road in the summer time is no way cool. I can see making Hp on a cooler day say in the fall or winter,however in the summer I don’t see how it’s possible. I’m sure on a dyno in a garage with a huge fan blowing directly on it yeah you’ll see some gain in Hp. However trying to get air off a road where it’s a 100 degress plus I don’t see it. The whole idea is to get colder air into the engine right? To truly get cooler air into the engine I believe you have to the air coming in from the top not the bottom of the car. Perhaps like a ram air/scoop I think that’s what Goldstar was talking about in at the start of this post. Up higher the air is always cooler as a rule right? The more north you go the cooler then air.. I would think the same for getting cooler air into the engine.

I am not nearly as knowledgeable as the rest of you when it comes to cars. However making cold air coming off a hot road doesn't make any sense....

[1Mazda323Fan]

Look again at the stock intake scoop. It's positioned directly under the hood of the car very near the radiator. So, the air is heated the instant it hits the scoop. A cold air intake will position the filter so it is as far away from hot engine components as possible, and will generally have some form of heat shield to further isolate it from heat. Some people even mount the filter in the fender of their car and put a heat shield in place to make the fender its own air chamber. As for the air coming off the road being as hot as underhood temps, I doubt that. Unless you're in the desert, then the odds are the temperatures under your hood are at least 50 deg. F higher than the road temp, plus the air actually hitting the filter will be cooler once the car gets underway. By placing the air inlet as close to that cooler air as possible, the intake charge will be cooler overall (it is still heated by the engine as it passes up into the manifold), thus being more dense and providing more air to burn the fuel charge with. The other main advantage of CAIs (and short rams too) is the increase in intake pipe diameter, as well as the open element filter. Both of these allow more air into the engine than the restrictive stock intake system will, as well as (generally) allowing a smoother intake flow into the engine, as the piping is made of smooth metal, as opposed to plastics which oftentimes will have ribs to allow for flexing, as well as acoustic chambers to keep noise levels down. As to your point of the air being cooler higher up, generally this is true, but I doubt that the air is that much cooler 2' higher up the car from where a CAI would be located (I may be wrong, however). Realistically, to get the coldest air possible, you would need the intake inlet to be as far forward as possible, which would put it in front of the hot engine components.

[goldstar]

Actually, installing a true cold air intake will net you a far bigger increase in power than just removing the MAF screen. A true CAI actually does sit near the ground, away from hot engine components where the air actually is cooler. What you're thinking of is commonly referred to a short ram intake, which, while it does sit close to the hot engine components, will provide an increase in power due to the fact that it has an open element filter, which allows more air to enter than the stock, restrictive air box and its associated straw. The construction of the intake pipe on both short rams and cold airs also improve intake air flow (smooth walls make for smoother flow).

Exactly what is your point? Since this thread is about modifying the stock air intake system what is the relevance of disparaging and discouraging a mod proven to be effective in reducing negative air pressure in the OEM intake duct because, according to you, a CAI will net a far bigger increase in power? I assume those who want, or have, a CAI would not be reading this thread.

Removal of the MAF screen is a good first step for those wanting to improve the performance of the OEM intake system, at absolutely no cost, and of course can be applied when using CAIs or SRIs as well.

Although I never intended this thread as an us vs. them discussion, since you raised the issue I'd like to address a number of points you made in your statement as CAIs may have some problems of their own. First, although the CAI filter resides in the wheel well and receives ambient temperature air, there is obviously no ram effect which has been demonstrated to be an effective aid in improving performance. Furthermore, Julian Edgar has found instances of negative pressure in the wheel wells of a number of cars meaning that the air intake of many CAIs, unlike that of the modded stock system, is actually in a low pressure area. Certainly a no-no for increased power production. For a more detailed explanation, go to:
http://www.wihandyman.com/forum/showthread.php?t=2921 post #2.

Second, the OEM air filter is not restrictive for its purposes and was used both for the normally aspirated Proteges and the MSP. Open element filters such as K & N used in many CAIs are less restrictive than paper types but are overkill, as well as being less efficient filters, for any Protege used as a daily driver. There is also the problem of oiling of the MAF. You don't really think Mazda would specify an inadequate air filter size, right? For more information about air filters, see:

http://www.wihandyman.com/forum/showthread.php?t=2777

http://www.wihandyman.com/forum/showthread.php?t=2370

Third, at least in respect to 3rd Gen Proteges, AEM maintains that a SRI drawing in underhood air makes more power than would a CAI because the longer tubing length of the latter would actually reduce power despite the ingestion of ambient air, according to their tests. Consequently they only sell SRIs for this application. Injen on the other hand, states that the CAI makes more power here than would a SRI, according to their tests, and this is all they sell. Who do you believe? I certainly don't know.

Finally, if I were to make a comparison between the modified stock system and a CAI (which I wouldn't), I'd choose the fully modded system rather than one with just a removed MAF screen.

I personally do not see how air coming off the road is cooler then where the air where it is coming on on our scoops. I understand cold air is denser but the hear coming off a road in the summer time is no way cool. I can see making Hp on a cooler day say in the fall or winter,however in the summer I don’t see how it’s possible. I’m sure on a dyno in a garage with a huge fan blowing directly on it yeah you’ll see some gain in Hp. However trying to get air off a road where it’s a 100 degress plus I don’t see it. The whole idea is to get colder air into the engine right? To truly get cooler air into the engine I believe you have to the air coming in from the top not the bottom of the car. Perhaps like a ram air/scoop I think that’s what Goldstar was talking about in at the start of this post. Up higher the air is always cooler as a rule right? The more north you go the cooler then air.. I would think the same for getting cooler air into the engine.

I am not nearly as knowledgeable as the rest of you when it comes to cars. However making cold air coming off a hot road doesn't make any sense....

Actually, although CAI air filters are located down low towards the road they are relatively sealed-off from the engine compartment and do receive ambient temperature air especially when the car is in motion. Under these circumstances I don't believe roadway heating is much of a problem, even in very hot weather, since its temperature also tends to vary as the driving environment changes. I believe the mean air temperature is the relevant variable here. As already stated however, such a location does not allow the inlet to benefit from ram air effects as is possible with the modded stock air intake system. Additionally, this location makes the air inlet particularly susceptible to water ingestion when running through standing water and can lead to catastrophic hydrostatic lock. One advantage of the air inlet being higher-up is not so much that the ambient temperature is appreciably lower than when the inlet is closer to the road, but rather we don't have to worry about this calamitous outcome. As for the principal factors that tend to affect intake duct temperatures, check out:

http://www.wihandyman.com/forum/showthread.php?t=47990

Happy Motoring!

[norwood1026]

Exactly what is your point? Since this thread is about modifying the stock air intake system what is the relevance of disparaging and discouraging a mod proven to be effective in reducing negative air pressure in the OEM intake duct because, according to you, a CAI will net a far bigger increase in power? I assume those who want, or have, a CAI would not be reading this thread.

Removal of the MAF screen is a good first step for those wanting to improve the performance of the OEM intake system, at absolutely no cost.

Although I never intended this thread as an us vs. them discussion, since you raised the issue I'd like to address a number of points you made in your statement. First, although the CAI filter resides in the wheel well and receives ambient temperature air, there is obviously no ram effect which has been demonstrated to be an effective aid in improving performance. Furthermore, Edgar has found instances of negative pressure in the wheel wells of a number of cars meaning that the air intake of many CAIs, unlike that of the modded stock system, is actually in a low pressure area. Certianly a no-no. For a more detailed explanation, go to:
http://www.wihandyman.com/forum/showthread.php?t=2921 post #2.

Second, the OEM air filter is not restrictive for its purposes and was used both for the normally aspirated Proteges and the MSP. Open element filters such as K & N are less restrictive than paper types but are overkill, as well as being less efficient filters, for any Protege used as a daily driver. There is also the problem of oiling of the MAF. You don't really think Mazda would specify an inadequate air filter, right? For more information about air filters, see:

http://www.wihandyman.com/forum/showthread.php?t=2777

http://www.wihandyman.com/forum/showthread.php?t=2370

Finally, if I were to make a comparison between the modified stock system and a CAI (which I wouldn't), I'd choose the fully modded system rather than one with just a removed MAF screen.



norwood1026, I'll get back to you as soon as possible to address the issues you raised by editing this post. Right now the mothers are coming.

Happy Motoring!

Forgive me I'm not trying to start anything I just personally never belived in CAI's.

[goldstar]

You have nothing for which to apologize. We're just having a civilized technical debate that emerged from the present discussion.

No one has done anything wrong.

Happy Motoring!

[1Mazda323Fan]

goldstar, I didn't mean to take things so far off topic. I was merely trying to explain to norwood how a cold air can improve performance, as he seemed unsure as to how they could be effective. I wasn't trying to suggest that anyone should choose a cold air over the mods you've described; I've actually used one myself to good effect (removing the plastic in front of the intake inlet). I do agree with the points you brought up in your riposte, especially the cost factor. Free is always better than $350. Again, I apoligise if it seemed like I was being disparaging towards the point of your write-up. It really wasn't my intention at all.

[goldstar]

1Mazda, no offense taken. I feel that I ought to apologize for coming on so strong here, myself. I enjoy technical discussions and sometimes I get so wound up in them that I don't always realize that I may have overstepped my bounds in trying to make a point causing others to think I'm attacking them. That certainly wasn't my intent here and I'm sorry if I gave that impression and misread the intent of your post. I look forward to further discussions with you.

Happy Motoring!

[Drive323]

How much louder does this mod make the car?

[goldstar]

How much louder does this mod make the car?

Welcome to the Forum.

As I stated in post #1, after the mod, "There was a noticeable increase in intake sound but nothing obtrusive - not at all like an AEM or Injen." Additionally, I found that the colder the ambient temperature, the more pronounced the intake noise. Both me and my passengers noted this phenomenon and I attribute it to the fact that colder air is more dense; i.e. a greater weight of air is being moved per unit volume, consequently tending to more noise in the intake duct.

However, when I originally performed this mod my car was still equipped with the OEM exhaust system. Once I switched to the Racing Beat exhaust system, the increased sound of the exhaust which is considered quite mild for an aftermarket system, completely masked the intake noise due to the mod.

I hope that answers your question adequately.

Happy Motoring!

[wanabemsp]

First of all im new to the forums. And this mod looks great! thank you for providing this information! So i was cutting the panel above the grill and i noticed that i accidently cut the supports in the middle that hold the grill together. But its still holding on at the end is this acceptable or would i have to get a new panel? Thanks i appreciate it.