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Hey guys,
What are your thoughts. 2012 duramax, should i go with the cheaper alternative if just a K&N filter or spend the $350 and get the cold air intake? its a tough call.. the filter is about $80. Your thoughts please and perhaps some experiences on one or the other or even both
Thanks
 

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Can you get a different brand in Australia? I use Spectre brands, and it's basically the same idea as K&N, but only costs $125.
 

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I've had two diesels and there is an opinion that you should not use an oiled filter.
Do a little "googling" on the subject. To me it makes sense.

Chebby
 

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Yeah ive had 2 diesels as well and they always said on my diesel forum that there is really no need for aftermarket cold air intakes and filters unless your pushing over 500hp, the stock box is good if your running stock tunes.
 

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^^^What he said. Diesel's don't rely on sucking in as much air like a gas motor does. I has a Dodge Cummins pushing over 450 horse and a intake added less than 5 H.P. when I put it on the dyno after installing it! Of course I didn't listen to all the folks on the forum at the time who told me an intake would be useless.
 

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I've heard that before, but I have two problems with that theory: Diesels use a lot more compression than gas motors; and turbos move a ton of air when they're spooled up. Wouldn't those two factors imply that a diesel would suck in more air?
 

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I can see your point, you would think it would work that way. Compression is what makes diesel fuel ignite, not as much air is needed. In a gas motor it needs a lot more air mixed with the fuel to make the combustion cycle complete. That's why diesels are far more efficient than gas motors. There is not as much wasted fuel during the combustion cycle on a diesel as compared to a gas job. As for the turbos, they usually push around 16-18 lbs. of boost on a stock diesel engine, where as a gasoline engine is usually a little higher, say between 18-21.
 

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^^^^ YUP well said! I mean its not gunna hurt anything if you go buy all the stuff and put it on there, the only thing its gunna hurt is ur pocket book. Its just not a huge if any performance gain from everything ive learned when i had one.
 

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Performance or not....I like the long-lasting air filter that doesn't need cleaned, and it's only $80 (check other stores too, that seems high). I'm going to put the filter on my Vortec as soon as the stocker that came with the truck last December gets dirty....

Does the oiled filter itself have any negative affect on performance in a diesel? Just wondering....
 

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Sierra12 said:
I can see your point, you would think it would work that way. Compression is what makes diesel fuel ignite, not as much air is needed. In a gas motor it needs a lot more air mixed with the fuel to make the combustion cycle complete. That's why diesels are far more efficient than gas motors. There is not as much wasted fuel during the combustion cycle on a diesel as compared to a gas job. As for the turbos, they usually push around 16-18 lbs. of boost on a stock diesel engine, where as a gasoline engine is usually a little higher, say between 18-21.
That makes sense... I'll probably put a CAI on every vehicle I own, since they look so cool :mrgreen: .
 

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I thought a cold air intake would help here in Texas in the summer, so I installed a Banks scoop and filter. No change that I could detect. Cooler air is sucked from in the fender area with the stock setup, anyway. I will not do it on my new 2013.
 

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A very common cummins mod is the bhaf, (big honkin air filter). It's basically the largest paper stock style filter you can get. The theory is potentially better filtering,(but not reusable) and more surface area for air to come in. No replacement for displacement. Google it and other diesel forums might have more information
 

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I installed a B&S Cold Air Intake (w/ oiled filter) into my truck the day before yesterday. I heard all the same comments; but in a certain forum on the interwebz a popular tuner spoke up and actually recommends them for our LMLs but not LMM or a couple other prior models. He stated that GM changed the filter starting in 2013 to a small flat OEM filter and are not the same quality as previous years intakes (to include the LMM). Well, like the rest of you I believe in cold air kits and got one anyways. Im glad I did because I can tell and feel the 6.6L is loving all that air. It idles quieter, shifts smoother, and actually has a little more get up and go. I cant really give an opinion on MPG as I drive extremely short distances to work and back. I also cant back this by any proof as I havent dyno'd the truck... but you can feel and hear the differance IMO (I am an aircraft mechanic so you can take that as you will). :twisted:
 

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Haha nice to hear. I'm sure all the speeding ticket's you'll be getting will add credence to your theory :D
 

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I dont see a benefit to buying a entire CAI for the new diesel trucks. If you had a LB7 Or LLY then i would say yes. But the turbo is going to pull the air it needs regardless of what CAI you put in it. Regular filter change is really the only thing needed. If you are upgrading turbos or adding a bigger injectors ECT then it would be on the more likely side that a CAI would be beneficial.
 
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