DIY Intake

Here we go. I accept no responsibility for anything that happens from following my instructions because.....we're all stupid for hacking up perfectly new cars.

This is what you'll need:
- a list of acronyms/definitions:
ID = inner diameter, OD = outer diameter, * = degrees, " = inches, = = equals
- strong constitution and morale checks (you will be defiling a factory new car and parts)
- 2" 90* piping
- 2" silicon hose couplers (2 straight, 1 90*)
- 7 2"+ hose clamps
- cone or mushroom air filter with 2" ID (or 2.5" ID like I did)
- some 1/16" thick rubber sheet 1" wide x 16" long (can use more if needed; will be cut down)
- 10mm sockets with ratchet and extension
- maybe and 8mm socket
- socket driver would really help
- hack saw or other metal cutting device that won't flex and mess up your cut
- a sharp blade
- scissors
- a file or sand paper
*If you use a 2.5" ID filter, get some 1/4" rubber to fit between the piping and the filter

WARNING: THIS WRITE-UP WILL BE FAIRLY INCOMPLETE BECAUSE I ONLY HAD THE IDEA FOR THE WRITE-UP HALFWAY THROUGH, BUT IT WILL BE EASY TO FIGURE IT OUT

So first you have to remove the stock air box. Undo the 2 10mm bolts at the front of the box and one behind the air box in the back, right corner. To find it, follow the vacuum hose from the stock intake plenum (ribbed rubber hose attached to the air box) back to the motor. One bolt is near the filler cap and the other above the cylinder #2 (middle) intake-runner-pipe-thingy.
Hereafter the bolts are undone, loosen the clamp at the throttle body, and loosen the vacuum hose from the rubber intake plenum. Remove and act like a rampant monkey after indulging on Twinkies.

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Now tha you have the airbox out, run into your room to start hacking the box *GASP* to get the sensor section out. The box will start like this:

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And end up like this:

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Note the size of the piping on the housing of the sensor. It will be 2" on the throttle body side, but 1-7/8" on the filter side. This is where you will cut a strip of the 1/16" rubber hose and wrap it around the 1-7/8" side and superglue it so it doesn't move. Otherwise your filter will fall off and the surge of air will make your engine go into limp mode.....like it did to me.
The little pieces of casting will need to be removed and cleaned up to get the final, round unit you'll be using.

Here's a view from the top of the sensor section:
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*MAKE SURE WHEN YOU START TRIMMING THAT YOU DON'T GET ANYTHING IN THE SENSOR PORT*

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And here is the unit all cut up:

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Make sure to clean up the cut areas:

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Now for a mock-up of the first half of the system:

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You will be cutting the side of the 90* pipe leading into the 90* coupler. Cut it down to 6". The goal is to have the couple + the 90* pipe = 10" total height. Also, cut the otherside that DOESN'T attach to the 90* coupler down so the straight section is about 1". Here is the game plan. But this isn't a game. Trim the pipe as needed but it is important to have the total section height at 10" so you can clear the intake manifold and the hood.

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In the end, it'll look a little something like this:

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Uh oh......more 1-7/8" sections. Just wrap and super glue the same 1/16" rubber to the throttle body to solve this:

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Use a hose clamp to fix the pipe securely to the 90* silicone coupler. Install the current piece you have made with another hose clamp (over the 1/16" rubber that you should have attached to the throttle body round part) and ready yourself to install the sensor section. Use the 2" OD side (with the sensor plug facing down) and attach one of the straight 2" ID couplers using a hose clamp. Then attach that using another clamp to the piece you've made. Now from the sensor side it should go:

sensor -> 2" coupler with clamp -> other side of coupler with clamp -> 90* pipe that bends down ->90* couple with clamp -> throttle body with clamp and 1/16" rubber wrapped around throttle body

*saying this section to yourself aloud while tracing backwards might help you get sorted out and oriented

So remember how you were supposed to wrap the 1/16" rubber around the filter-side of the sensor as well? IF NOT DO IT NOW BEFORE THE WORLD BLOWS UP. Then fit the other straight 2" ID coupler over that side of the sensor with yet another clamp. Now remember that section you cut off of the 90* pipe to attach the sensor? If it's long enough, cut that down to about 8" and insert it into the couple with another hose clamp. Otherwise you have to source a section of 2" OD pipe and make it 8".

If you chose a 2" ID filter, you can just slap that on at the end of the 8" pipe section with a clamp. If you were like me, it's not over yet.

If the filter you chose had a 2.5" ID, you'll need to get a piece of 1/4" rubber to fit into the filter opening. If 2-1/4" filter ID, then 1/8" rubber.

Remember that if you have enough 1/16" rubber, you can just layer it over and over to get the right thickness.

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When it's all slapped together, it should look like this:

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How you get the filter and pipe to stay still is up to you. I personally am still trying to figure out a way that makes it look cool and suave. I have failed thus far.

Wow..I applaud your cavalier attitude! I definitely would be too timid to hack up anything on my new car!

May I ask what was the motivation for doing this? Are you trying to attain any sort of power gain from this?

-Charlie-

Gutsy. Good write up.

Sorry gguuuuyyyyyysssss.....4 pictures failed. Here they are in respective order:

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As for the motivation Charles, I bought the car to build a lightweight, nimble monster. I'm hoping for measurable gains, although I have found the car easier to get moving from a stand still and at lower rev ranges, on top of actually pulling +3-4 kPa across the rev range over stock.

Upon close inspection of our cars, wouldn't it be better to put the air filter in front of the engine, on the passenger side of the radiator? There's plenty of cool air there.

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Originally Posted by 91cavgt

Upon close inspection of our cars, wouldn't it be better to put the air filter in front of the engine, on the passenger side of the radiator? There's plenty of cool air there.

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I had tried that already. It makes for a lot of low-end torque loss and with the way the motor is tuned, the top end isn't as great either. Air temps are about the same considering the oil pan is right there too. I actually reverted to the SRI for this reason. Really and truly, the only way I see a CAI working well is you have to retune the ECU settings.

But here is what it would look like. I could add an additional write-up for that path as well if you want.

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Pretty awesome. Is there any slack on that sensor wiring?

Excellent write up, thanks! Your thread has been added to the index sticky.

If the sensor can be moved, I can imagine running the pipe and cone down in front of the driver side fog light. I think that would be about the same, maybe less piping than stock, but will look better than the top mount.

Thoughts?

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Originally Posted by Ares

If the sensor can be moved, I can imagine running the pipe and cone down in front of the driver side fog light. I think that would be about the same, maybe less piping than stock, but will look better than the top mount.

Thoughts?

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I like the idea, plus it would eliminate the 180 degree bend that is needed to mount the filter on top of the motor, thus it should be less of a restriction. The biggest downfall would be mounting the air filter lower increases the chances of water ingestion if you were to drive through deep water.

Wouldn't recommend permanently modifying an OEM part without a backup. I bought an extra part of my OEM intake (the underhood scoop), specifically to cut it with a hot knife to direct air to and under my short ram intake. Now that I am trading my car up, I just put the OEM one back on, because the modified version will lose me more in value than the part is worth AND, if you ever need dealer work (warranty), you now have a mod you can't undo, and could work against you. I would imagine the maf section (tube only)probably costs <$30.

Aye. I intend to get another box section if I sell later, but I'll be starting to get really down and dirty with the car next year so I've waived my warranty.

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Originally Posted by chris_top_her

Wouldn't recommend permanently modifying an OEM part without a backup. I bought an extra part of my OEM intake (the underhood scoop), specifically to cut it with a hot knife to direct air to and under my short ram intake. Now that I am trading my car up, I just put the OEM one back on, because the modified version will lose me more in value than the part is worth AND, if you ever need dealer work (warranty), you now have a mod you can't undo, and could work against you. I would imagine the maf section (tube only)probably costs <$30.

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For those that are concerned about their warranty, this is spot on!

Reversible is the key word!

Interesting. Our units don't have a MAF, only a MAP sensor :)

Nice work!

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Originally Posted by 91cavgt

I like the idea, plus it would eliminate the 180 degree bend that is needed to mount the filter on top of the motor, thus it should be less of a restriction. The biggest downfall would be mounting the air filter lower increases the chances of water ingestion if you were to drive through deep water.

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From what I've heard (never experienced) from other car forums, the filter has to be totally submerged for water ingestion. If I were to use this set-up, I would never drive any more than half a foot worth of water, just to be safe.

Just last month I was driving through water up past the bottom of the doors on my focus haha. That would scare me. That was on my hill. The road, on top of the hill, was flooded. We had a bit of rain.

I'd route it above the exhaust for a WAI and better fuel economy.

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Originally Posted by Ares

From what I've heard (never experienced) from other car forums, the filter has to be totally submerged for water ingestion. If I were to use this set-up, I would never drive any more than half a foot worth of water, just to be safe.

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It all depends on the length of the intake, throttle opening, and the amount of the filter that is underwater. If only a portion of the filter is under water, but there is enough suction in the intake, it can suck water into the engine even though the filter is not completely submerged.


I've got a bent connecting rod in my garage from a hydrolocked motor. Luckily it was not mine. It was from a friend's SRT-4. Not a cheap fix either.

anybody know what the mitsubishi part number is for the maf housing is? is it stamped on there somewhere?

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Originally Posted by btavish

anybody know what the mitsubishi part number is for the maf housing is? is it stamped on there somewhere?

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There is no part number. You'd have to buy the whole intake box or at least the half with the MAF housing, if they sell it like that.

If you are like me and didn't get the fog light package you could simply pop out the plastic piece and run your filter in that general area allowing for some pretty cool are to hit it...just one idea

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Originally Posted by chris_top_her

I bought an extra part of my OEM intake (the underhood scoop),

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I dont really understand what you mean by this. Please explain what exactly are u talking bout?

The MAF sensor housing is built into the air cleaner box.

More info here:

Developing a MAF sensor housing for custom air intakes


If you're looking for a MAF sensor housing for aftermarket intake, look here:

For Sale: MAF sensor housings for custom intakes

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Originally Posted by Rival Autosport

It makes for a lot of low-end torque loss and with the way the motor is tuned, the top end isn't as great either.

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Wait, are you saying it loss power in low end too? or were you saying OEM actually lacks low end torque because of how the OEM intake was mounted?

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Originally Posted by codenamezero

Wait, are you saying it loss power in low end too? or were you saying OEM actually lacks low end torque because of how the OEM intake was mounted?

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I actually have to recant my initial statement. I believe my initial results were attributed to the car having such low mileage from the which the ECU adjusted it's tune.

It does still lose some bottom end power, although not much, but mid-range gains a good bump and top end a slight raise in power. I only noticed this when comparing the setups when the car was over 20000kms, whereas before it was really low. Alos, in that time I changed from Sunoco 94 (10-15% ethanol) to Shell 91 (100% gasoline).

Could you describe at around what rpm the gain/loss were? I mainly aimed to increase the torque around 2500-3500 rpm, since that's pretty much the sweet spot of where the CVT operates. And on highway, it almost never reaches under 2000 rpm. Do you also have scangauge to see whether it runs more efficient?

I don't have any dynos as this was all butt dynoed and the gains were very gradual so no specifics. But I would say around 26-3700 probably saw the biggest gain, and the car just felt like it pulled harder near top end, but not drastic as the change for mid-range power.

Also consider that the CVT will make your gains differ slightly as to how much and where you gain, based on gearing, engine load, etc.....

Yes, I have a Scangauge but I've never paid attention to the numbers from before other than load and intake volume. So I can't give you any clear information that'll mean much. I just noticed a couple of documented differences and the way that the car felt.

I installed a intake simailar to yours and I had a rough idle. I was wondering if you had any thoughts on how to get rid of that rough idle.

Did installing the intake make you have a rough idle?

Welcome to the forum, 2017orangemirage!

I'm not sure if you'll get a response from Rival. He doesn't have his Mirage any more.

Maybe make an intro thread and ask there? Might get more eyeballs on the question.

I've sold a bunch of the MAF housings for people to make custom air intakes. I haven't had any complaints of anyone having issues with rough idle.

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Originally Posted by 2017orangemirage

I installed a intake simailar to yours and I had a rough idle. I was wondering if you had any thoughts on how to get rid of that rough idle.

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Are you saying this only happened after you changed the intake or did it always idle rough and you never noticed it til now? All mirage engines shake a lot at idle but it's not really noticeable when you're sitting in the car, but open the hood with it running and some people might think something is wrong. It's normal for the engine to shake around.

does it matter if the stock intake tube is missing? mine broke and i just removed it. seemed to run the same. i just wanted to put some mesh over the holes to stop the noise echo in the engine compartment Attachment 20918

You won’t notice too much of a difference, the the intake temperature is going to be higher, higher intake temperature = less dense air = less power. But I doubt it would be noticeable.

Mitsubishi did revise an air dam for the 2017+ mirages to direct more cold air to the intake snorkel. They wouldn’t invest effort in updating it without reasoning. I would buy a replacement intake snorkel from E-bay or see if there’s a Mirage in a Pic-a-part near you. Wouldn’t be too expensive.

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Originally Posted by Gingerfly

You won’t notice too much of a difference, the the intake temperature is going to be higher, higher intake temperature = less dense air = less power. But I doubt it would be noticeable.

Mitsubishi did revise an air dam for the 2017+ mirages to direct more cold air to the intake snorkel. They wouldn’t invest effort in updating it without reasoning. I would buy a replacement intake snorkel from E-bay or see if there’s a Mirage in a Pic-a-part near you. Wouldn’t be too expensive.

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yeah when i popped it off and looked how it was it just didnt seem like the air would be much coller 12 inches forward from the hole. the water overflow part is just worthless. i think ill just make a tube to go somewhere to get cooler air

I did this to my 2014 in 2015 and haven't had any issues with it.