Air Intake

A majority of the questions I get are about my air intake, so hopefully I can cover it all. I guess it isn't a true intake system because no one makes a smooth one piece pipe that goes between the air mass sensor and the throttle body for the Mazda 323. So I really should be calling it just a cone filter, but I like the sound of intake better.

Why would anyone get an intake? The selling points are: an increase in horsepower, an increase in torque, and better gas mileage. So you're probably asking: Why don't car manufactures put them on their new cars? Well everything usually has a downside. In this case the increase in horsepower and torque isn't all across the power band. You actually lose some in the low end. The increase only comes at higher rpms. Also, intakes generally make the engine sound louder, not a lot, just enough to annoy old people. People that hear my car at full throttle think I have a sport muffler when all I have is the stock one. That's why there is a snorkel type tube connected to the stock 323 air box, to keep the sound down.

Here's a picture of my intake. Parts you'll need to know about are labeled.

Adapter

For the intake, you can use any sort of cone filter you want, but be aware there are performance differences in the style you choose. More on that later. The first step is to find someone that sells an adapter with a 3" opening so you can hook it up to your air mass sensor.

Here's my adapter without the cone filter on:

Notice the placement of the bolts as yours will have to look exactly the same.

The best place to buy one will be a local import tuner shop. If you've never seen one they usually have a bunch of slammed Hondas out front. If there isn't one in your town you could check out these websites that sell adapters. Special thanks to Dave Richardson for finding them.

http://www.lightningmotorsports.com/index1.htm Just scroll down the page until you see Filter Adapters. The adapter you want is the one labeled Toyota Adapter 3" Inlet. This is the exact same one I use because the dimensions given are the same as mine, approximately 1-3/8" and 3-3/8" center to center. It costs $25 US.

www.ptuning.com It says this adapter only works for 90-95 Mazda 323s but from the picture it looks the same as mine. The only problem with this one is that you also have to buy the Tenzo R filter at the same time. So you might not get the filter you want, unless you like that style. But at $69.95 US, it's a fair price for both of those items. Update: it's been pointed out to me that if you contact p-tuning, you can buy the adapter by itself and it will only cost you $19 US as of 11/01.

As with buying anything on the web it's buyer beware. I have never bought anything from these sites so I don't know how reliable they are. At least we know the adapters are out there.

Cone Filters

The filter I use is called the Ractive intake and it's made by Toucan Industries. The cool thing about this one is that it has a removable heat shield as part of the filter.

As you may or may not know, a gasoline engine needs air to run. An engine will perform better if this air is cool. This is because cold air is denser, or has more oxygen molecules, than hot air. The area under the hood can become very hot so the thinking behind the heat shield was to try to keep some of the hot air away from the filter. Ideally you would want to partition off the whole area around the air filter to keep the heat out. That way you'd have a nice little reservoir of incoming cool air. That's pretty hard to do with this car so the heat shield right on the filter makes sense, it just seems a little gimmicky to me.

I bought my filter from my local import tuner shop. But I've seen them around online. I've also seen them in the Summit® Racing catalog for $39.95, it comes in blue, yellow, carbon fiber-look, as well as red. I’m not sure if Summit sells it online. You can use any cone filer you want, just make sure it's not taller than 5" and it has an opening of 3" in diameter or else you might have trouble finding space for it under the hood.

Comparison

As an experiment and because I had to clean my filter, I installed the filter from my brother's car, into my car. He has a Tenzo R style filter, like the one that is being sold on the Ptuning website link above. Here's a picture of it installed:

At first glance, the two filters appear to be the same size. But it's not until you take off the heat shield from my filter that you realize how small it actually is. Mine is on the right:

The difference here is the amount of surface area each filter has. The Tenzo R filter on the left has the potential to be able to suck in more air than the Ractive filter. This translates into a small but noticeable difference when I was driving around. Since I don't have the ability to hook my car up to a dyno to see the actual performance gains or loses, I had to let the seat of my pants be the judge. I could only find two differences while I was driving.

Both of these filters are an improvement in throttle response over the stock air box. But I felt the Tenzo R style filter had a slight edge in responsiveness over the Ractive filter. I would assume it's because of the larger filter surface area.
Both of these filters make the engine sound better than it is compared to the stock air box but I felt the Ractive filter had a better intake note (kind of a growl) at full throttle. When I took off the heat shield and tried the filter it sounded kind of plain, just like the Tenzo R style filter.

In conclusion: If you want the cool sound (though it's not loud), and you like the look, go with the Ractive filter. If you want your car to be incognito, but still want the benefits of a cone filter, go with the Tenzo R style filter. As for me, I think I'll stick with the Racitve filter until I get a sportier muffler, then I'll switch to the Tenzo R filter to take advantage of the larger surface area.

Installation

If you have your cone filter and adapter you're now ready for installation. I have misplaced my stock air box so I can't remember every step that I did. It's a good idea to save all your old parts just incase something goes wrong with the aftermarket ones. Tools you might need for this job would be some screwdrivers, and some pliers or a ratchet set.

Okay, here it goes. You’ll have to take out the air filter box, the old air filter, and the little snorkel that’s connected to the side of the box. There is also the ignition coil that has spark plug wire connected to it, you’ll need this or else your car won’t start. Open up your air filter box first and take out the old filter. I think that’s where the screws are that hold it down. You'll then need to unscrew the air mass sensor from the air box. To fit the new cone filter on you screw the adapter to the air mass sensor where the old air box was by using the old bolts. You then can connect the new filter to the adapter. You should be able to figure it out. One problem is finding some way to hold up the air mass sensor and the new filter because it doesn’t have the air box to rest on anymore. I went to the hardware store and got some of these metal strips that have these holes in them. They look like the ones that came in those old toy “erector sets”. It’s the same stuff they use to hold the rails for garage doors on the ceiling. You can bolt them down to the car using some of the bolts that held the stock air box down. You might need to bend them so they can hold up the air mass sensor and the air filter. I also bolted the ignition coil to a metal strip to keep it in one place. You can refer to the pictures above for help on what it should look like.

Good luck.