# Air intake to prevent air filter freeze up?



## Snown13 (Oct 23, 2011)

Hey guys I am new to the site and learning a ton. I have been plowing 3 years in 1500 w/ 7'6 snoway. This year I got an 04 duramax crew cab and a 9'2 boss vxt. So I am new to running a diesel. A local mechanic told me I need a smb intake or my trucks air filter will freeze up. Anybody have this happen? I never had any issues with my 05 1500 freezing. Thanks


----------



## 2COR517 (Oct 23, 2008)

Subscribed....


----------



## carkey351 (Oct 18, 2010)

???? I live in Minnesota and haven't heard of that before...guess I so look out for it, even though the last 10years were fine...ussmileyflag


----------



## Snown13 (Oct 23, 2011)

He told me that the stock system pulls air from the wheel well so it will freeze up and choke the truck and if I bought a s & b it will not freeze up as easy. I have never heard it until today and having never run a diesel truck to plow snow I didn't know if this was a real issue or a hypothetical problem. I have been searching the internet on the subject and I cant find anything.


----------



## maverjohn (Jul 23, 2008)

Mite be a snip hunt your on?


----------



## dieselss (Jan 3, 2008)

Are you still running the stock air cleaner assm.?


----------



## mayhem (Aug 25, 2006)

Start by following the air intake for your truck and see where it draws its air from. Many vehicles pull air in through one of the front fenders, but the air path starts at the front of the vehicle and goes through a silencer setup inside the fender, but doesn't pull actual intake air from inside the wheelwell.

If you think about it, pulling air from inside the wheelwell wouldn't be very effective. At highway speeds thats a significant low pressure zone.

I think you should check your mechainc's advice...I don't suppose he just happens to have an SMB intake for your truck for sale, does he?


----------



## DuraBird02 (Oct 26, 2011)

I have an 02 duramax and i have never heard of this issue. I do currently have an S&B air intake and besides the so called "freezing" that i'm not sure exists, you will get an increase in fuel mileage. When i purchased my truck, i was getting about 13 mpg. I put a S&B intake and a Superchips programmer on it and now i get around 19. Well worth the money with the price of diesel fuel! Good Luck


----------



## larboc (Dec 8, 2009)

The programmer did it, not the intake. With a turbo, light load bsfc won't be very sensitive to a slight decrease in intake restriction.


----------



## theholycow (Nov 29, 2002)

I agree about the intake's effect on fuel economy. What is being sacrificed by the program to produce a nearly 50% increase in fuel economy? GM has plenty of motivation to use every trick in the book with the stock tune, except where they need to compromise for some other purpose (power, longevity, maybe emissions but burning that much more fuel is bound to make _more_ emissions)..


----------



## DuraBird02 (Oct 26, 2011)

larboc;1342441 said:


> The programmer did it, not the intake. With a turbo, light load bsfc won't be very sensitive to a slight decrease in intake restriction.


Thank you for your expert advice on my truck, but added them at different times. I put the programmer on it, and got 3-4 mpg better. Then a few months later i added the S&B air intake and got an extra 2-3 mpg better. So, the air intake did improve my mpg.


----------



## chevyman83 (Nov 25, 2010)

Op was not an issue with the 04 but a huge issue with the 07 nbs duramax


----------



## campkd6 (Dec 7, 2007)

I just modded my stock airbox. I think the PPE website had the pictures of where to cut still run stock filters no need to upgrage intake unless you are trying to put up some big numbers. Any have plowed in all conditions for the last 4 years with Duramax's and no freeze ups.


----------



## campkd6 (Dec 7, 2007)

Is your 04 and LB7 if so you can also port and polish the intake horn as it is very restrictive and will help with air flow and horsepower. Also have done the high idle mod so I can use the cruise control to bump up the idle. Done it to mine and several of my buddies trucks and works great for warming up or charging batteries etc.


----------



## larboc (Dec 8, 2009)

theholycow;1342542 said:


> I agree about the intake's effect on fuel economy. What is being sacrificed by the program to produce a nearly 50% increase in fuel economy? GM has plenty of motivation to use every trick in the book with the stock tune, except where they need to compromise for some other purpose (power, longevity, maybe emissions but burning that much more fuel is bound to make _more_ emissions)..


Emissions are the compromise for light load fuel economy. The biggest effect is injection timing. The programmer advances start of injection closer to mbt which gets a slight improvement on combustion efficiency (from like ~99.5% to ~99.7%) and a significant improvement in the thermodynamic efficiency resulting from the increase in time that the expanding gasses have to act on the piston because combustion started earlier before the exhaust valve opens. This all results in higher bsfc and lower egt's because you are extracting more of the heat energy into mechanical energy before you blowdown.

The higher combustion temperatures from more advanced timing encourage nitrogen and the excess o2 prevalent in a diesel's lean combustion mixture to combine to form oxides of nitrogen.
I think this random graphic from google images explains it nicely, I could find something more official from an sae paper, but it's a similar story. It is of course a much more complicated story on a modern diesel with vgt, egr, etc. but the same old rules for a ci engine still apply.










As far as a new air intake affecting fuel economy, I'm very confused how there could be any measurable effect unless you are driving around wfo a during significant portions of your drive cycle. The ecu is going to target a certain MAP regardless of a couple kPa reduction in pre compressor pressure.
I'd more suspect different driving conditions. Speaking from experience with testing fuel economy over a real world drive cycle, it is considered excellent to get under 5% test to test variability doing simulated city drive cycles over the exact same course the same day with the vehicle's systems up to operating temp.
Are your conclusions based solely on highway FE numbers?


----------



## theholycow (Nov 29, 2002)

Great response. I learned something new today. I don't usually see people who can even grasp the concept of BSFC, let alone know how and why it's affected. Thumbs Up I'm surprised that there is _so much gain_ to be found in timing, but other than that it makes sense to me.

For the effect of the intake on fuel economy, the usual culprits are inaccurate measurement (as described above) and placebo effect on driving style. However, I'll grant it this much: If it's measured decently and sustained long-term the it doesn't matter whether the mechanism is technical or placebo, results can be enjoyed just the same.


----------

