Truth on Cold Air Intakes

[clinebarger]

Originally Posted by Keith Seymore

There are some "architectural" things we did, too, that you might not notice. These were required to even give us a shot at getting in the game.

The '96 and beyond GMT400 models had the round element air cleaner on top of the fender, with the battery in the RF corner (passenger front) of the engine compartment.

It became obvious to me that I needed a flat filter in that spot to minimize the turns in order to even have a chance at meeting the aforementioned very aggressive flow requirement. So - I started a movement to displace the battery to some other location. Naturally the battery guy wasn't very happy about that.

We were stuck in a stalemate until the Chief Engineer, Ken Sohocki, took notice and called us into his office. He made each of us pitch our idea. In my case, I had actual flow data generated on the bench using rapid prototype material, and could demonstrate the effects with objective test data. The battery guy's response: "but we've always been right here".

The Chief's direction was swift and clear: "Seymore - you get the front corner. Schaule - find another spot".

So he moved the battery to the front of dash (rear of the engine compartment) so that he would have some structure to support his bracketry.

The engine air induction has been in the RF corner since that time, for GMT800, GMT900, K2 and now T1 generations of full size truck.

K

Thanks!! I love hearing about how these trucks came together!

Gas trucks have the battery on the left front corner of the engine bay, Dual Battery trucks like mine have 1 in the left front corner & the other in the right back corner like you stated. I have 1 persistent problem with that location, Rain water finds its way into my right side battery & the acid overflows. Was there ever a fix for this? 2006 2500HD LBZ Duramax, 5/06 build date, Flint assembly. Running a AC-Delco battery also.

What was going on with the Air Intake on the '04 1/2-'05 LLY Duramax?
From what I can tell from TSB 06-06-04-036D the air filter assembly was to restrictive & caused some engines to heat while towing in high ambient temps.

Did you design the '06-'10 LBZ/LMM air intakes with the big Donaldson filters? And why go back to a panel filter for the '11 & up LML trucks?

[69gmcc10]

Originally Posted by ptc

Not necessarily..... Intake filtration system resistance to airflow is restriction. Restriction is typically measured in units called inches or millimeters of H2O vacuum, and is defined as the difference in static pressure between the atmosphere and the outlet side of the system being measured. The higher the restriction the harder an engine has to work to obtain clean air for combustion.

So if the total AREA of filtration was enlarged then you would have less restriction without just making 'bigger holes'.... you think these two trucks have the same size filters?

I will not argue with you on increasing filtration surface area and its positive effects of increasing flow because you are correct. It is one of the key benefits of a funnel style filter, increased surface area in a given area. But you will be hard pressed to find a "high performance" or "high flow" drop in "stock style/shape" (K&N, spectre AFE,...) replacement aftermarket air filter with near the surface are of a stock filter. I am not saying you are wrong by any means, quite to the contrary as stated above, but in an apples to apples comparison of a filter fitted in the stock air box and looking at the common aftermarket products available and there significantly fewer number of pleats in the same designated footprint, I cant rationally see any other way to get more flow through less area than by poking larger holes in the media.

To my own shortcomings in this conversation, I am also not factoring in filtration media efficiency.

I would love someone to be able to drop some knowledge on the subject of filtration media and how oiled or dry high performance filters can significantly cut down on surface are and maintain high particulate filtration standards. Also I would like to see a discussion and data on engine life expectancy and how an increase of particulate matter consumed by an engine at various levels effects the engines longevity and long term efficiency. More to the point, with the use of a less restrictive filter in "hopes" to gain fuel and power, what are the long term costs vs any possible benefits of not using a factory filtration unit? And finally if there is truly a filter company and/or media that actually maintains as high or higher particulate filtration as stock and increases air flow within the parameters of the stock air box?

[Willie 66]

69gmcc10:

I'm sure they exist. I design liquid cooling systems for different types of equipment and when sizing straining elements, I can either choose a perforated sheet or a mesh style filter, amongst others of course. The perforated sheets tend to have larger individual holes than mesh filters do, but the mesh filters typically have a much higher open area percentage than the perforated sheets, even while straining out finer particulates! Look up Titan Flow Control - they have a cool "screen selection guide" that helps put it in perspective.

http://www.titanfci.com/technical-data

Not sure what technology these "high flow" auto filters use, but I'm sure it's something similar. Just because it's "high flow" doesn't mean larger particulates can get through.

[69gmcc10]

Originally Posted by Willie 66

69gmcc10:

I'm sure they exist. I design liquid cooling systems for different types of equipment and when sizing straining elements, I can either choose a perforated sheet or a mesh style filter, amongst others of course. The perforated sheets tend to have larger individual holes than mesh filters do, but the mesh filters typically have a much higher open area percentage than the perforated sheets, even while straining out finer particulates! Look up Titan Flow Control - they have a cool "screen selection guide" that helps put it in perspective.

http://www.titanfci.com/technical-data

Not sure what technology these "high flow" auto filters use, but I'm sure it's something similar. Just because it's "high flow" doesn't mean larger particulates can get through.

Willie,

Thanks for the link and the info, that guide seems pretty objective as it just compares filtration media and weave differences and not guiding you to a specific filter. Being a visual person the images and the filtration data being side by side helps. The index clearly shows that "some" of the mesh filters do have a tighter weave and have as much open air or more than their looser counterparts and are filtering finer media. Further more, glancing at the data there seems to be a correlation between diameter of the woven material and the weave density leading one to believe there is a "sweet spot" in that relationship.

Thanks again

[Keith Seymore]

Originally Posted by 69gmcc10

I would love someone to be able to drop some knowledge on the subject of filtration media and how oiled or dry high performance filters can significantly cut down on surface are and maintain high particulate filtration standards. Also I would like to see a discussion and data on engine life expectancy and how an increase of particulate matter consumed by an engine at various levels effects the engines longevity and long term efficiency. More to the point, with the use of a less restrictive filter in "hopes" to gain fuel and power, what are the long term costs vs any possible benefits of not using a factory filtration unit? And finally if there is truly a filter company and/or media that actually maintains as high or higher particulate filtration as stock and increases air flow within the parameters of the stock air box?

We have all that; alas - I'm afraid I don't have it at my fingertips and no longer have it all memorized.

It does remind me of a few salient points, though:

a) One of the reasons we went away from the Donaldson round filter and back to a Dephi flat panel for the GMT800 is because we felt it we could achieve comparable filtration with less flow restriction.

b) Also - you gain filtration as the filter gets more "dirty": the particles themselves provide a physical barrier and allow less dirt to pass through.

c) You'll notice we screwed the box lid down with phillips head screws, rather than clips like the previous generation. That was a conscious choice in an attempt to discourage folks from opening up the box for a look. Disrupting the filter can knock loose dirt down into the induction system, which is more damaging than just leaving it alone.

d) Lastly - we did offer a HD filter option RPO K47 for more hostile environments, which consisted of a different media with deeper pleats for more load carrying capability. We also included a restriction gage on the box to provide an indication that the filter needed changing, but for most applications on predominately paved roads the LD filter was intended to last for tens of thousands of miles. K47 was released as optional on the small engines and standard on the larger engines.

K

[Keith Seymore]

Originally Posted by clinebarger

Thanks!! I love hearing about how these trucks came together!

Gas trucks have the battery on the left front corner of the engine bay, Dual Battery trucks like mine have 1 in the left front corner & the other in the right back corner like you stated. I have 1 persistent problem with that location, Rain water finds its way into my right side battery & the acid overflows. Was there ever a fix for this? 2006 2500HD LBZ Duramax, 5/06 build date, Flint assembly. Running a AC-Delco battery also.

What was going on with the Air Intake on the '04 1/2-'05 LLY Duramax?
From what I can tell from TSB 06-06-04-036D the air filter assembly was to restrictive & caused some engines to heat while towing in high ambient temps.

Did you design the '06-'10 LBZ/LMM air intakes with the big Donaldson filters? And why go back to a panel filter for the '11 & up LML trucks?

I had moved on to program management by the time the GMT800 was launched (1999 calendar year) so can't speak directly to some of the rationale.

My current project is using the LML engine (I have the exterior sheet metal, if you can believe that) and I do recognize many of the components the Induction guy is carrying around.

K

[Willie 66]

NEW UPDATE:

Watched gas mileage increase after removing CAI, and I still haven't changed my driving style. Here's the stats:

Traveled about 280-300 miles constant highway, then two days of 20-30 miles each in Houston rush hour traffic. With CAI, I got 13-14 combined MPG. Without, I got 16 MPG easy. (I am one of those guys who meticulously monitor the trip meter and divide by the gallons I put in at each fill-up to find MPG). I make this trip somewhat frequently, so it was easy for me to test this out.

Hope this helps y'all trying to figure out if you want a CAI or not.