beating a dead horse aftermarket intake::

[madpowerstroke]

I just wanted to clear a few things about stock vs aftermarket intakes. While the stock intake is good alot better than other factory intakes, it still suffers on flow. I have seen and done some testing, with stock turbo runs good, and you won't have to upgrade even with a performance tune. Now if want the most out of your truck then get rid of stock and get a aftermarket intake, and the stock turbo will run better, and you will get a increase in rwhp.
If you go to a bigger turbo then forget about it, get rid of the stock intake, the filter will not flow enough air at wot for the turbo to run really good. The turbo pulls air with the blades, think of this example you fuel pump: and electric fuel pump pulls fuel but not as good as pushing fuel. So the turbo sucks in air but pushes it better. Now back to fuel pump, if the fuel line is small the pump will have to work harder to suck the fuel, pressure will be fine at idle and mid, but at WOT the pressure will stay the same but the flow(volume) won't be there. Now if you increas the fuel line and make it bigger it can now flow more volume of fuel and the pump won't have to work as hard to suck the fuel. At WOT the pressure and volume of fuel will be there, so the turbo same way, the stock filter flow good and low to mid good. But WOT air flow is there but not volume so the turbo is working harder to suck air in and doesn't have the volume of air it needs.
I have seen this alot with the bigger turbos, they need alot more volume of air that the stock intake and filter cannot provide, once changed to aftermarket the turbos run alot better, remember one thing turbo are always connected to exhaust, so if turbo has to work harder it has to by increasing exhaust pressure, which increases EGT, not enough volume air can't get in to get out to work the turbine to work the compressor.
I hope that helps understand the reason for getting rid of stock intake for aftermarket, for stock turbo or bigger turbo.
Thanks, MAD

[windrunner408]

"The stock intake still filters better"

[xjeeper]

I have been saying this forever, my first 04 6.0 was dynotested in early 04 for an offroad magazine article, and the Airaid intake produced it's claimed power increase on an otherwise stock truck, and I have run one ever since.

[JIM_C]

MAD, I think a lot of us have bought in to the belief that the stock intake is the best up to ~500 hp. You're saying that aftermarket intakes can show an increase in hp to the wheels on a stock truck - what kind of increase? And does better flow of aftermarket automatically mean poorer air filtration?
What were your tests and which aftermarket intake is best?

[JIM_C]

Originally Posted by xjeeper

I have been saying this forever, my first 04 6.0 was dynotested in early 04 for an offroad magazine article, and the Airaid intake produced it's claimed power increase on an otherwise stock truck, and I have run one ever since.

What was the claimed hp increase?
Do you still have the truck? What do the turbo fins look like?

[windrunner408]

I dont expect this thread to make a whole lot more head way with this subject than previous attempts have done. Basically it comes down to flow and filtration. Which filter will give the highest flow with the best filtration.

YES AFE and S&B intakes have been dyno tested to show the advertised gains of 15-20hp with a stock truck on a performance tune.

ISO tests have shown that S&B kits filter to 99% of what the stock filter does and provide nearly 40% more flow when clean.

The only downside to the aftermarket Cold Air Intakes is that they have a VERY low capacity to hold dirt so it requires more frequent cleaning. For some folks this is acceptable and for others it is not. This is where the subjectivity comes into play of if the stock filter flows more air when the aftermarket filter is at its capacity. Regardless, for me, I dont have any choice but to run an aftermarket filter with a turbo that pulls so much air.

The question you have to ask yourself is do you think the extra flow will give you the performance number you are looking for??

[colo_dually]

Lets see how many threads I've made similar statements in:

Write Up: Power Potential of the 6.0L PSD
New Air Filter
Build Thread: TowBoss F350 6.0L PSD.

And that's just recently. Now here's the counter point (other than the beaten horse of the stock unit supporting 500RWHP): The stock unit holds 1303 grams of dirt, dust and debris you don't want running through your investment. Where as even the best aftermarket filter will only hold 170 grams. [Source: S&B's independent test, failure point reached at 28" vacuum] That puts a replacement of an aftermarket unit at 13% of the life cycle of the stock Donaldson.

I agree it will hold most builds back by 15-25RWHP depending on level of performance, turbo selection, and electronic tuning. But that number is in the over-3,000RPM band, not down low where I doubt most drivers will notice the change in power itself, but instead focus on the intakes audible differences and turbo performance.

There are those of us, who cannot, or choose not, to discard the filtration provided by the stock airbox, Adrian. Now with the statements made in the first post, are you trying to say there will be issues if the MTW is ran on a stock intake?

We know the "Durastroke" has been abused and used heavy under towing with Wikewa, with no adverse effects. Do you feel it is different with the Hybrid, and larger stage turbos?

This isn't a bash on you Adrian, I actually enjoy this debate on the ORG. Typically gets some good information passed.

On Edit: I did just notice another post of yours Adrian, concerning a Stage 2 owner running a stock filter, then shifting to aftermarket. Have any other details?
I'm looking at the Stage 2 or Hybrid, as most folks here know, utilizing the stock box and rarely operating over 3,000RPMs.

Another theory of mine, perhaps we can start getting some MAF numbers on these turbos with stock and aftermarket intakes, get some solid numbers and put an airflow ceiling to the stock box for the purpose of discussion?

[PGreenSVT]

I for one run an Airaid intake with a pre-filter and have had it on my truck since I got it. Yes it certainly shows that it doesn't filter as well as the Donaldson in my UOA reports but it certainly flows better and I have not seen any evidence of turbo damage from what does get through it.

Now as for the air flow requirements let me say this. In my Airaid the oem filter minder is in the intake tube after the filter. This has not been any issue at all with the stock 05 turbo, an 03 turbo, or a Powermax with a Batmowheel. However, the first run on the dyno at PHP with Adrian's stage3 turbo slammed the filter minder shut so hard that it won't reset and I have to replace it. It won't be going in the intact tract any more.

So yes, there is considerably more flow with the stage3 and I wouldn't consider running a Stock air filter with it or anything bigger. If you want to take maximum advantage of the increased airflow of a bigger turbo then go to an aftermarket CAI. The filtration on the S&B is almost as good as on the Donaldson, just requires more frequent maintenance. Now if you are investing in a turbo to get 50 or 60 additional HP do you really want to leave 20 of that on the table due to the air cleaner?

[njmudrat]

I read all these posts about CAI's...My question is,is it really worth the 3-400.00 invvestment on a stock or slightly modified truck?I understand on a highly modified powerstroke but on a stock truck I just don't think you will feel the 15-20hp gains or see any mpg increase.So are you just getting some xtra air flow ......

[windrunner408]

Originally Posted by PGreenSVT

I for one run an Airaid intake with a pre-filter and have had it on my truck since I got it. Yes it certainly shows that it doesn't filter as well as the Donaldson in my UOA reports but it certainly flows better and I have not seen any evidence of turbo damage from what does get through it.

Now as for the air flow requirements let me say this. In my Airaid the oem filter minder is in the intake tube after the filter. This has not been any issue at all with the stock 05 turbo, an 03 turbo, or a Powermax with a Batmowheel. However, the first run on the dyno at PHP with Adrian's stage3 turbo slammed the filter minder shut so hard that it won't reset and I have to replace it. It won't be going in the intact tract any more.

So yes, there is considerably more flow with the stage3 and I wouldn't consider running a Stock air filter with it or anything bigger. If you want to take maximum advantage of the increased airflow of a bigger turbo then go to an aftermarket CAI. The filtration on the S&B is almost as good as on the Donaldson, just requires more frequent maintenance. Now if you are investing in a turbo to get 50 or 60 additional HP do you really want to leave 20 of that on the table due to the air cleaner?

Well put Mitch... That is impressive that Adrian's Stage 3 sucked so hard it broke your filter reminder.

Originally Posted by njmudrat

I read all these posts about CAI's...My question is,is it really worth the 3-400.00 invvestment on a stock or slightly modified truck?I understand on a highly modified powerstroke but on a stock truck I just don't think you will feel the 15-20hp gains or see any mpg increase.So are you just getting some xtra air flow ......

Well I for one think unless you are going to stick with a completely stock truck, then I would recommend a CAI and turbo back exhaust if all you planned to do after that was tune the truck. This is of course unless you dont care. I just know that I saw better fuel mileage from a turbo back exhaust and CAI. Also the S&B only costs about $270 tops. I find it worth it unless you live in dusty conditions. JMO.