Cold Air intake Upgrades

[seafish]

Adding more (filtered) air IS a benefit, but that is done by the turbo PUSHING the air into the engine. The stock airbox on these trucks flows enough CFM for up to 500 HP, so it really doesn't do much to flow change the filter box. Now, changing some of the downstream tubing HAS been shown to net some gains in either egt drop or higher hp, though most of htese gains are within a dyno's margin of error, though many people do not want to admit that All that being said, you are absolutely right in that of course, any owner should do what they want to do to their trucks, but it is important to also remember that these forums are about an exchange of ideas which are hopefully based in fact, not just desire. Just my .02

 

[PC12Driver]

In the beginning of the 24v era, it was believed that the plastic cone between the airbox and the fender was a great source of restriction. If you wanted "more air," you could simply pop out that piece to drop egts and gain a few HP. Then came along the BHAF (Big Honkin' Air Filter) idea, where you'd toss the airbox all together and just strap on a 4" generic filter from NAPA or somewhere that would just barely fit under the hood. Obviously something that size would have to pass even "more air", resulting in even lower egts and more HP. Then came the various aftermarket "airbox" kits that still used the BHAF idea, but used their own high flow air filter (turns out the term "high flow" most of the time referred to dirt and oil in addition to air, but I digress...) surrounded on a few sides by powder coated sheet metal.

Finally, someone did an actual test (I dont recall which issue, maybe 2004-ish) and found that the stock air box, with the "restrictive" fender connector installed and a drop-in AFE Pro Guard 7 resulted in the best results up to around 450 HP while sucking 40 psi of boost. Turns out the turbo does a good job of pulling what air it needs, quality is better than quantity, and a mildly modified street truck will not see an advantage by changing out airboxes.

I wish I had the money back I spent on air filter systems for my last truck.

 

[AH64ID]

The stock intake is pretty good, and the filter is not the limitation on older trucks. The 13+ trucks got it right! you have to move a lot of air for 385hp.

On the older trucks I think the best setup was the stock box, Home Depot intake mod, with an Airaid MIT. The lower directional vanes on the 04.5-07 also help at low flow.

I am making about 425-450 rwhp and run a larger turbo with a cam that moves a lot more air than stock. I run the above setup and a stock filter, and the filter minder doesn't move.

 

[nicktoday]

Adding more (filtered) air IS a benefit, but that is done by the turbo PUSHING the air into the engine. The stock airbox on these trucks flows enough CFM for up to 500 HP, so it really doesn't do much to flow change the filter box. Now, changing some of the downstream tubing HAS been shown to net some gains in either egt drop or higher hp, though most of htese gains are within a dyno's margin of error, though many people do not want to admit that All that being said, you are absolutely right in that of course, any owner should do what they want to do to their trucks, but it is important to also remember that these forums are about an exchange of ideas which are hopefully based in fact, not just desire. Just my .02

I agree - I have gone down the "Stage 1" to "Stage 3" on every one of my trucks. Part of it is I enjoy tinkering with my truck. I know for some it makes no sense... I have also found more air is a much better option for any of my trucks. Part of this is my desire and part is my belief in the what I have been able to get out of my trucks in the past.

 

[AH64ID]

The 6.7 uses a MAF, and it's not uncommon for an aftermarket filter to set off a code from too much air. In order to keep a CEL from setting the filters had to have outer filter sleeves added to restrict flow to stock levels.

I fully understand the tinkering desire, but there has to be a noticeable gain from a mod and I don't think an air intake will do that on a 13+. If you want to tinker get an older truck

 

[nicktoday]

The 6.7 uses a MAF, and it's not uncommon for an aftermarket filter to set off a code from too much air. In order to keep a CEL from setting the filters had to have outer filter sleeves added to restrict flow to stock levels.

I fully understand the tinkering desire, but there has to be a noticeable gain from a mod and I don't think an air intake will do that on a 13+. If you want to tinker get an older truck

Thanks for the feedback - as you said you don't "Think" that an air intake will do this or that. I am of a difference opinion and many others are. Thanks and at this point I have read everyone's feedback and will go down my path. I have been talking three people that have the S&B and two that have the AFE. While neither has been able to go Dyno none of the 5 have reported any CEL. Thanks again for your opinions!

 

[AH64ID]

Out of curiosity I just looked up the filter used on the 13+ trucks, and it's the same as the 07-12. So yes it moves more air than the engine needs for stock power levels, or even 100rwhp over stock. It's been about 12 model years since an air intake was needed until over 450-500 rwhp, but they still sell since people think they add gains.

 

[Cummins12V98]

It's clear that there is two camps one that believes that adding more air is a benefit and one that doesn't. I'm not telling anyone else to take on the modifications I will...

Thanks for answering the question…….

On the older trucks it made sense. I have a Big cone type filter on my 98 12V. But it is not needed on my 11 HO for sure.

These new trucks are great right out of the box.

But it is your money.

 

[nicktoday]

Thanks for answering the question…….

On the older trucks it made sense. I have a Big cone type filter on my 98 12V. But it is not needed on my 11 HO for sure.

These new trucks are great right out of the box.

But it is your money.

I agree - I just had it washed today and it's just a great truck, beautiful as well as strong. I love the interior in mine as well. I know that some are not crazy about don't anything to their trucks and that's cool. I an many others feel different... and yes... my money and my truck

 

[sag2]

I don't recall the name of the gentleman or his company, but he was at May Madness and had actually run dyno tests on the different CAI systems out there. The conclusion was most resulted in a loss of power, not a gain. The biggest problem with aftermarket reusable filters is most people do not service them. Failure to service will result in dusted engine and no warranty. So as long as you know that, keep the economy rolling.

 

[kewltrks]

So if you were to change your inner cooler (Banks) could you still run a stock intake system?

 

[6V92TA]

if a turbo diesel's volumetric efficiency is above 100% in stock form ( it is) how does improving air flow with no other modifications accomplish much ?

 

[jhenderson]

Depends. Is your new intercooler going to bring you over 500rwhp? A more efficient intercooler doesn’t necessarily mean more air. Just cooler air and less restriction for the turbo.

 

[6V92TA]

correct me if I am wrong but is the charge air cooler not after the turbo charger?

 

[Will_R]

I'm not going to support changing to a CAI, but here is an engineering perspective on the subject.

As people have said before, an engine is an air pump, so let's break it into some basic principals. Air in, fuel, exhaust out.

As air flows, the pressure and resistance increases as the square of the velocity. Moving too much air through a small diameter increases the amount of energy required to move the fluid. This goes for both intake and exhaust. Anything we can do to reduce restrictions to flow and there for reduce the amount of energy required to move the fluid will improve engine efficiency (mileage)

So, in theory, a larger intake and exhaust should decrease energy losses, BUT what is the percent increase? Lets just say we can decrease energy loss in the intake and exhaust by 15%. Now figure that intake and exhaust are only a small portion of the energy cycle loses for the complete engine. By the time you look at bearing and cylinde friction intake and exhaust losses are maybe only 5% of the whole engine. So your 15% improvement is really only a 0.75% for the engine.

Now take another step back and think about the truck rolling down the road and all the friction there; air resistance, rolling resistance on the tires, losses due to drive line or transmission/transfer case, etc. Now your intake and exhaust are an even less significant percentage (5%?), so you 15% now becomes 0.11% of the frictional losses.

So, yes, there might be a gain, but what's the dollar/to value?

A friend on mine was all excited to buy a TRD intake for his Tundra because they advertised 8 hp gains. I told him he was nuts because how much did he pay for that to "bump"?

In the end, if the system is designed half right, how much gain is there to be had overall????