Air box mod DIY

[ASD Dad]

Before I get too much into this look here : http://www.titantalk.com/forums/titan-performance-modifications/15837-diy-air-box-mod.html

 

This has been going on with the Titan 5.6 since it came out over a decade ago.  

 

In a nutshell Nissan made a long snorkel that extends into the factory air box for NVH reasons (noise).  That puts the air intake right up against the corner of the box and also takes up volume in the box.  Neither are good.  If you look at your air filter you will notice that most of the dirt is in the corner where the intake tube ends vs. the entire filter.  Mine was dirty after a couple thousand miles in that corner while the rest was brand new looking.

 

After doing this mod the air box volume increases and the whole filter is being used more efficiently.  I noticed a very very negligible amount of noise increase.  You can also help this mod by doing a drop in filter like an Airaid, K&N, etc.  

 

OK, that out of the way it is very simple to do to our NV's and so far it HAS helped in MPG believe it or not.  I really see zero harm in trying the mod out, there is no risk to the motor and the noise barely noticeable if at all.

 

There is one slight difference with the NV vs. the Titan.

 

1) There is a 10mm (all bolts are 10mm) bolt that is tucked inside a recess of the air box towards the front of the vehicle.  You will see it down past the windshield washer reservoir.  

 

I could not get a wrench or anything else into that recess with the reservoir in place.  You will need to use your 10mm socket and remove the reservoir or move it to the side enough to get a wrench onto that bolt.  There is one hidden bolt on the reservoir UNDER it.  You will feel it and just need an extension to back it out.  Once that is moved I disconnected the wires and moved the whole thing out of the way so I could get a box end wrench on the recessed air box bolt.  

 

I did NOT remove the lid of the air box like in the link above, there was more than enough slack and room to move the lid off towards the firewall.

 

Once the bottom was pulled out I used a small flat head screwdriver to wedge into the tab holding the snorkel in.  It pulled right out.  I then cut the snorkel to length and it snapped right back in.

 

I did this mod 5 tank fulls of gas ago.  I monitor every tank and hand calc each fill up.  Before this mod my average was 14.1 MPG.  Since doing this mod I am now averaging 14.6 MPG.  A whole 1/2 a MPG!  Yes, that is paltry and pathetic but hey, it is free and easy.  Some guys are seeing more gains with an aftermarket filter.  For me this was a proof of concept mod.  If it worked I was going to do a full Airaid intake as they are seeing much better gains using it and it has repeatable dyno results across multiple motors.  I am more interested in the HP gains for towing vs. MPG gains but they are seeing decent results there.

 

Before anyone asks or states: my daily commute is a boring one.  Between working full time and having two kids in therapy up to 70 hours a week combined my 7 day a week drive is very very routine.  Every day is the exact same drive, same traffic, same everything.  This isnt like I did the mod and took a trip or decided to go all over the place.  It was the same old same old over the course of the test.

[RICK]

Interesting they force the intake air into the far corner.

 

My real question to you is my 2014 3500 high top is only getting mid 5 - high 7 mpg. Ive never broken 200 mikes on a 24 gallon fill up. Worse was 133 miles. I do carry approx 2000# full time, but that is only 50% of capacity.

 

Dealer said nothing can be done, salesman said he's never heard of that.

 

What kind of driving do you do to get so much better mileage.

 

I only have 2300 miles since new 12/30/14.

 

Rick.

[ASD Dad]

Interesting they force the intake air into the far corner.

 

My real question to you is my 2014 3500 high top is only getting mid 5 - high 7 mpg. Ive never broken 200 mikes on a 24 gallon fill up. Worse was 133 miles. I do carry approx 2000# full time, but that is only 50% of capacity.

 

Dealer said nothing can be done, salesman said he's never heard of that.

 

What kind of driving do you do to get so much better mileage.

 

I only have 2300 miles since new 12/30/14.

 

Rick.

 

Rick, seems that the average mileage for a V8 NVP is in the 14 MPG range which is right where I sat.  My best tank so far is highway at  70-75 mph at 15.3 mpg.  I know that speed is too high for optimal mpg but speed limit is 70 and I am not about to hold up traffic to gain one or two mpg.  

 

Your mileage seems crazy low!  I would be selling my van if I only got that mpg and they couldnt figure out what was going on.

[axulsuv]

ASD ; 

Interesting that you put this up , I cleaned the K&N in my 1500 V6 yesterday morning (after around 35k , overcleaning and oiling kills K&N's !) and just a sliver of the filter edge showed any dirt at all . While the filter was drying I happened to log on and see your post :).So having a little time on my hands I got out my flexible shaft dremel/rotozip (big one I use for porting heads etc.) and put a small cut off wheel tip on it and cut the snorkel carefully without removing the airbox . It ended up just about flush with flange it snaps into , cleaned up any rough edges I created and vacuumed the box out and reinstalled the filter . Only put about 10 miles on it yesterday , but my Butt-Dyno says low rpm response and torque is a tick better , no discernible noise change .

 As my van is a freak and gets fantastic mpg , (22mpg round trip to NC. last weekend for a trials event with bike trailer) I'll run a few tanks around town and see what she does . Sure as heck won't hurt anything .

 Glenn 

[Tatunka]

I just did this today as well, we'll see what the butt dyno reads tomorrow.

[Tatunka]

Just posting my results, there is a change in the amount of noise. I think it sounds better, more throaty, but as far as get up and go, it seems to be about the same. I guess to accurately measure that you would need a real dyno.

[axulsuv]

Not long term results , but after a weeks worth of driving my normal commute (in the dog days of summer, ac cranked up ) my mileage avg. display has settled at 20.1 ... Usually @ 19.6 by now . I still feel low rpm response a bit better , and I can hear the intake now , not offensive though . I've got a trials event next month that will be just over a 1000 mile round trip That I've done before , so we'll see how she performs .  

[ASD Dad]

Happy to hear this mod is working for others!  I still think I may add an Airaid intake in the near future.  Titan and Armada owners swear by them, even ones that have done this mod.

[axulsuv]

:love_shower: OK  ... 1180 mile round trip , with about 3 hrs. parked in Atlanta traffic @ 98degrees with the ac cranked , 2 bikes on trailer , one in van , 3 big coolers and all of our other gear in van  ... 22.5 average for the trip by pen & paper ! mpg monitor showed 23 at one point .

about 2 mpg better than last year !!! GREAT BASIC MOD , THANKS!!!!!!!!

Glenn

[ASD Dad]

Thank the many Titan owners who've been doing this since they came out!

 

22mpg is crazy good for a van this size. My wife's Sienna gets around 23. I'm guessing you have the V6...

 

I have since installed tge Airaid intake but have only taken it on two trips towing so can't tell if there is any mpg increase. There is most definitely a horsepower increase along with noise especially under load. When not towing it's fairly quiet but when towing it can get loud on hills. I'll do a report on the intake once I get some some mileage on it.

[hawk259]

I have since installed tge Airaid intake but have only taken it on two trips towing so can't tell if there is any mpg increase. There is most definitely a horsepower increase along with noise especially under load. When not towing it's fairly quiet but when towing it can get loud on hills. I'll do a report on the intake once I get some some mileage on it.

 

Please do, as I have been looking at the Airaid and Banks intakes.  I am leaning towards the Airaid, but worried about the extra modifications needed for either system due to the larger engine bay.

[ASD Dad]

Please do, as I have been looking at the Airaid and Banks intakes.  I am leaning towards the Airaid, but worried about the extra modifications needed for either system due to the larger engine bay.

 

The only mod needed on the Airaid was a simple 4" rubber coupler available at Home Depot or Lowes for $6.  The Airaid coupler is about an inch too short.  Everything else bolted right up as on a Titan/Armada.  

[radin2son]

If I got this right, you replaced the oem air intake, that was previously modified by moving the intake hole to the center to improve air/filter flow, with the airaid intake kit (about $350 if I was looking at the right one). I looked at the kit on line, but how does the airaid improve air flow and mpg when compared to oem?

 

7/31 Actually, I got the modification description wrong... I misread it. Other posters said was so simple so I re-read it and now get it. You cut down the snorkel (inside the air box) to increase the air flow across the filter. The interior snorkel end was too close to the filter...

Edited July 31, 2015 by radin2son

[axulsuv]

yep ,  bare bones 1500 v6 :)

  and my trials riding buddies envy it !!! :)

Edited July 23, 2015 by axulsuv

[ASD Dad]

If I got this right, you replaced the oem air intake, that was previously modified by moving the intake hole to the center to improve air/filter flow, with the airaid intake kit (about $350 if I was looking at the right one). I looked at the kit on line, but how does the airaid improve air flow and mpg when compared to oem?

 

You are exactly correct.  I paid $300 on Amazon just watching the price go up and down which was the lowest I could find it, plus I can return it if I find it doesnt do what I hope.

 

The Airaid tube and filter and HUGE compared to stock, I can take a photo of it in the engine bay but you can see photos online of it installed on Titans or Armadas.  The tube is 4" in diameter vs. what I believe is 3" stock.  Yes it reduces down at the throttle body but there is a massive volume of air flow over stock.  There are many guys with their own dyno tests with this intake vs stock or other companies and the Airaid beat them all easily.  

 

You can definitely feel the difference in the mid to upper RPM range and it's not just from the additional noise.  I've been playing with modding engines for a long time and the gains on this intake are honestly surprising.  Most modern engines are pretty much tweaked from the factory and you may gain a tiny bit here or there.  The 5.6 Nissan motor really wakes up with intakes and exhausts.  

 

Next on the list - Bully Dog GT tuner.  This actually flashes the factory ECU with a new set of parameters to do everything from firm up shift points, change engine timing, etc.  There are three good ECU tuners for the 5.6 with the UpRev being the best.  UpRev is the highest cost but can be fully custom and is normally only recommended if you go full header, b-pipes, exhaust plus custom intake.  BD GT and Superchips are similar in what they can do.  I like that the GT is also a visible "scan gauge" you can setup to monitor any number of things along with engine codes.  

[radin2son]

Airaid is based just up the road in Phoenix. There are quite a few choices, red/dry filter or blue/oil filter and 2 types of air boxes ($297 or $374). No reviews but there was a generic warning that these may not meet California and other states' emission standards. Airaid has a "contact us" on their site and they should be able to say what they can sell in California etc. At least I hope they could...

 

In the alternative, do you or Axulsuv think Airaid's washable cotton fiber filter oem replacement ($78) is worth considering. They claim better air flow etc. Unless driving in extremely dusty conditions, they recommend cleaning the filter every 30-50k. No reviews.

 

Thanks for the explanation.

Edited July 23, 2015 by radin2son

[ASD Dad]

CA has VERY strict emissions laws.  You cant touch anything that could be possible emissions related or they wont pass you.  Just look at a Bully Dog tuner - the 49 state version is about $100 or more cheaper than the CA version!  If you are an aftermarket tuner you have to make things extra for CA. I would be shocked if their full intake was CA legal but it could be.

 

Here in SC they could care less, I could run open headers with no catalytic converters all day long.  

 

I had another brand washable filter in my Tundra.  I bought it since it was a lifetime filter and I used it since new.  I could simply wash it, dry it and pop it back in vs. buying a new filter.  They claim a small horsepower increase from better flow on most but you'll never be able to tell that small of an increase unless the stock filter was super restrictive.  

 

It's really up to you - spend $15 every 30K miles for a factory filter and you would need to keep the washable filter for 150,000 miles to equal the price!  

 

If you go that route anyway, I would search online to see if you can find it for less.  My Tundra filter was $80 from the company and I think I only paid $50 for it.

 

Lastly - I dont recommend the oiled filters.  Some can flow a lot more air but it can be tricky when it comes to re-oil it after cleaning. Too little and you lose filtration.  Too much and you can start fouling your MAF and throwing CEL's.  The Airaid intake oiled filter flows a lot more air than my dry Synth filter but I didnt want to mess with the oiling.  

[radin2son]

ASD Dad, Is your NVP also a daily driver, not just a tow vehicle? Do you expect your "daily" V8 mpg will be better than the 14 to 15+ mpg average

people, not RICK, are getting. Or, is your primary concern more power when towing? Thanks for the info.

 

I wonder if any other NV 1500s are getting similar mpg as axulsuv. If so, Nissan should exploit this and go after diesel buyers.

[ASD Dad]

NVP is definitely a daily but we camp 4-5 times a year.  The mods are all for power when towing.  I was quite shocked coming from the Tundra's 5.7 motor and lighter weight.  That motor produces a lot more HP and TQ stock than most modded 5.6 Nissan motors.  

 

I dont expect to gain much if any MPG vs. the 14-15 I get now.  I sort of hope for a repeatable 1 mpg difference since the snorkel mod worked.  The snorkel mod really just confirmed suspicions that the intake is restrictive from the factory.

[Wallyc]

Did this mod and I noticed about 10 mile increase in a tank full of gas . I drove the van for two months the way it came and then I did it. The motor seems to respond better, but how much better? Don't know . I also checked the filter and way more is catching dirt now. Noise level has gone up on acceleration but I like it.

[ASD Dad]

It's a great and free mod that I would recommend immediately to any owner of the 5.6 motor.  I am still happy with it nearly 18,000 miles later.

[JB Harlin]

Did this mod yesterday.  I am not a machinist by trade, but I have spent many an hour cracking a lathe and mill and I am pretty handy with most tools.  By far the most difficult task it getting the tube out of the air box.  Before I removed it I marked the tub as far as I could about 3/4" from the inside of the box, to get the correct entry angle.  Once I fought the tube out of the box, I wrapped a piece of paper around it to finish the mark around the circumference and scribed it with a utility knife.  Cut off the excess with a coping saw, sanded the end flush, deburred the edges and polished them with a buffing wheel.  When reinstalled the tube now protrudes about 5/8" into the air box.

 

Do not have any gas milages numbers, this is the 6 cylinder NVP SV.  One thing I did notice right off the bat  was much smoother throttle response.  We'll see how this works out. 

[Wallyc]

I have the v8 and yes the response seems to be better. Mileage went from 344 range to 356 after a couple of tanks of gas according to the computer. I will say though mine is a cargo van with a large two hundred pound tool box(empty) with close to four hundred pounds of tools plus bins and truck stock so it's no light weight. It also helps I don't treat it like a dog either just a slow and deliberate pedal . I am no engineer but even I know more air in the better a Motor can breath after all it is a big air pump:-) it's be a great, useful mod I'm glad I did . I've shown a few local nv owners that are very happy about it too.

[timavogel]

ASD Dad-

 

Should this technique work on an NVP V6 as well?  Or, should at least have similar effect if not the same effect?

 

Thank you,

 

tim

[ASD Dad]

ASD Dad-

 

Should this technique work on an NVP V6 as well?  Or, should at least have similar effect if not the same effect?

 

Thank you,

 

tim

Tim, it should work with the V6, JB did it to his 2 posts up! Doesn't hurt to try. I'm still happy after 25,000 miles of driving.