DIY: Free Intake (WAI) - Altima Forums.net - The Nissan Altima Enthusiast Talk and Discussion Forums

MurphDurph · 12-08-2009

I searched the site and did not see that this had been done. If it has please remove this thread.

I had been told about the Free WAI mod since I got my car a few weeks ago and upon researching it the write up I found wasn't very good. So I decided to make my own. Hope you enjoy.

This is good for all 3rd gen Altimas (02-06)

Tools Needed:
- Flat Head Screwdriver
-Good roll of tape
-HiFlow replacement filter (optional)

Start by popping your hood. Just above the grille you will find what looks like a ram air scoop held in by 4 plastic pins.

Now, you must remove these pins. You can very easily do this with a flat head screwdriver like I did.

After removing the pins the air duct will try to fall, since it's not being held in by anything else. Put this in a safe place. If you choose to sell your car in the future and want to return it to stock you will need it.

Make your way around the driver side and push down the 2 metal clamps holding the top of the air box on. After doing so I found it easier to loosen the clamp holding the intake tube to the air box and setting it like pictured. You don't have to do this if you have an easier way of positioning it.

Remove your air filter. After doing so you will see a BIG hole in the air box to the front, and a not so big hole in the bottom of the box.

You will take your tape and cover this bottom hole. This is not entirely necessary, however, doing so will make sure that all the air your intake pulls in will be from the front.

This is where you would insert your replacement filter if you chose to buy one.

Put the top of the air box back on and clamp it down. Along with reconnecting the intake tube if you chose to disconnect it like I did. And you will be left with this....

I'm not sure if you can tell in the picture but the pins from the first step I reinstalled into their mounting holes just so it was 1 less thing that I needed to worry about finding at some point.

Take it for a spin. For less than 10 minutes of work the sound is pretty good. It's not aftermarket by any means but it's breathing that much better for $0. Unless you spent the $40 on a K&N drop in filter.

ALL MODIFICATIONS DONE TO ONES CAR ARE AT THE OWNERS RISK. MURPHDURPH NOR ALTIMAFORUMS.NET ARE RESPONSIBLE FOR DAMAGED PARTS/VEHICLES.

DJ · 12-08-2009

Excellent how-to! Definately sticky material.

MurphDurph · 12-09-2009

Thanks DJ! Thought I could contribute something that didn't take very long, and everyone can do.

MurphDurph · 12-10-2009

I was actually searing google for WAI kits and if you type in "WAI nissan altima" this is the first response. Sweet!

DJ · 12-10-2009

Nice!

05altimact · 01-29-2010

This is just my 2 cents so don't be offended, but it may sound better but did you notice any gain in HP?

You removed the air scoop which only allowed cold outside air (not hot air from the engine compartment) into your intake. All engines produce better HP with cold air entering the intake, and it was forced through the way Nissan intended it to be. Now you have hot air swirling around feeding your intake. Sounds like a loss of HP to me!

Why do you think they put the weather stripping on the air scoop?
To keep out as much hot air as possible!!!

If anything I would have blocked off the hole you did but still put the air scoop back on for cold forced air at highway speeds! But that hole may have been put there to allow water and other debris to fall out short of going into the intake.

Again just my 2 cents!!!

MurphDurph · 01-31-2010

Have you seen the gap between the hood and the grille that it's channeling air from? It's less than a 1/4" tall. I understand that that's where it would get cold air from, but come on, the gap is just too small and the ducting curves so much that you're probably not gaining anything by having it. Secondly, I put a MAC Intake on my Explorer when I had it and all it did was draw hot engine air through the intake and I had increased throttle response and increased mpg. Try something before you criticize it.

05altimact · 01-31-2010

I'm not criticizing, I'm questioning!
What does WAI stand for? Tell me it’s not Warm Air Intake!
Being new to cars made in Japan, I never heard of a warm air intake as an upgrade, unless of course you live in Alaska and are looking to warm the engine up quicker!!!

So please explain to me what a WAI is and what the benefits are.

I’m just saying, it defies all logic, CAI’s improve power, the stock setup is basically a CAI in a way, but there is too much restriction in the way it is routed to the air box, and the narrow opening you mentioned leaves room for improvements!

I still think the engine will make more power with cold air than with warm, but this is my first Nissan so I could be wrong!!!

I agree that what you did will work good now in the winter months, but are you planning on leaving it like that when the weather warms up? If so I don’t thing it will run as good, and there’s a chance you’ll damage the maf sensor. Again just my 2 cents, not meant to criticize your setup! I’m just trying to understand the logic behind it. And again I’m new to Nissans so maybe there is a reason for a WAI that I’m not understanding.

MurphDurph · 01-31-2010

I've basically done what people who get short ram intakes get, but for free. I'm not saying that I'm getting any more power than I was before. I like the "intake having" noise, and this was free and took about 10 minutes.

I have done this (pic below) for free. Warm engine air into the intake, but without spending $200. Economical

05altimact · 01-31-2010

Ok, but why warm air instead of cold air?

Do these engines run better with warm air going into the intake?

All American made V8's that I have owned ran better with CAI's.

Are these 2.5's just the opposite, preferring warm air over cold?

MurphDurph · 02-03-2010

You're reading into it too much. Yes, engines prefer cold air over warm air. You WILL see an hp gain with more cold air. I'm not disputing that. I did this because it was free and took 10 min.

duran6 · 02-16-2010

quick question how well does this work on a 3.5?

Penguinchit · 02-17-2010

Your butt dyno will say it's effective, but a lot of that could be psych because of the more aggressive sound. I don't know of anyone who's ever dynoed with just an intake mod.

Definitely worth the free mod though.

05altimact · 02-17-2010

I tried it and wasn't impressed with the low rpm noise it made (buzzy), at higher rpm's it sounded good, but like I said before, you're allowing hot air from the engine into your intake and that's not a good thing!
Also for the week I tried it I did notice a slight drop in mpg's!
I put the oem air scoop back on when I saw the mpg drop.
But it does give the engine a more aggressive sound, but mostly over 3000 rpm.

ScaryJerry · 02-18-2010

I saw this could be done when I first got my 02' but I didn't really give it a shot until I saw this. I agree, gas mileage drops a bit but the car does get a more aggressive sound. Duran I have the 3.5 and this works pretty well