Air filters

[flatbed56]

Well here we go. I have a AFE intake filter stage 1, a friends idea is the stock filter is better then the AFE, in that it is not sealed good enough to keep the hot air from the engine from being sucked in,and that these type of filters itself will get pin holes and allow dirt in, thus losing horse power, were as the stock air filter draws from the cooler air in the fender and do not get the pin holes, any thoughts.............thanks

[Mopar1973Man]

Ok... Here is the low down on filters...The whole CAI (Cold air intake) is over rated. The fact that colder air does produce more HP/TQ but there is a couple of problems.1. The turbocharger will heat the air as it pressurized. So it up to the intercooler to cool it back down.2. There is a coolant passage in the manifold that re-heats the air.Now the 2nd one I studied heavily. The fact is the IAT temp start out the same as outside air temp while the engine is cold so as the coolant temp rises the IAT temp will start to rise over outside air temp. Then it typically settles at about +40*F over outside air temp. It doesn't matter if you have a pipe all the way to the grill, stock air box or BHAF without a heat shield it remain the same rule. +40*F over outside air temps at 195*F worth of coolant.So now looking at the filter media... I'm not fond of any kind of oiled filter because of the fact like you pointed out that if you can see pin holes that means dirt can get thorugh. Not to mention if you wash the filter the wrong way you can litterally push the dirt to the other side of the filter and allow the engine to suck it in next time. Now the BHAF is a completely seal filter media. It a dry media that does require washing, oiling, etc. I've cleared over 102K miles on mine and still going. I installed my filter minder in the head of the filter and it not moving yet. But I do test the filter minder and its still working fine...Now a MPG secret I found... If the IAT sensor rises above 100*F the MPG jump upwards towards 21-23 MPG's! So is colder air really needed??? :confused:

[flatbed56]

Thanks for the reply, that does help, If I have this right, either filter you will still get about same heat. I would think the big issue is how well it filters the dirty air. The AFE I am running is the dry micro filter material, no oiling. I am curious what are you running for a filter....thanks

[Mopar1973Man]

I'm running the BHAF from VulcanPerformance... It only cost $40 bucks... It lasted 5 years and 102K miles so far of dust dirt roads. The turbo and intake is clean! http://mopar.mopar1973man.com/personal/2002/bhaf/bhaf.htm And the link to VulcanPerformance... http://www.vulcanperformance.com/Search ... earch=BHAF

[flagmanruss]

There are 2 subjects...A ) one is the ability to filter (clean) the necessary volume of incoming airB ) CAI (Cold Air Intake)A ) IMHO, the stock airbox & pleated paper filter does a decent job of keeping dirt out of a stock engine. This is a balance of restriction & air volume that is hard to beat. There may be better elements... at extra cost... but this is the baseline. We don't want any more restriction & certainly not less dirt stopping ability.I had tried a drop in K&N oiled filter... in over 10,000 miles I never saw any increase in mpg. I disguarded it because of concerns of the ability to clean the air as well as base line & the occasional oiled intake that has been reported. This may not matter in a gasoline race engine that will be torn down at frequent intervals but I hope that's not in my future. As a test, I had run the stock air box with NO filter at all... and I never saw any increase in mpg. So my experience is that the pleated paper filter is not the restriction on the stock motor... perhaps the air box / turbo itself?? I am back to running a quality pleated paper filter in the stock air box on my stock engine. One of these days I plan to splurge on a drop in NanoFiber.Modded engines add fuel, need more air both in & out to keep the EGT in the proper range. Need upglades in filter capacity & exhaust. It's kind of futile to upgrade the air filter & leave the stock exhaust. I'm not planning to mod the truck, if I was I'd be looking to increase the airflow.B ) IMHO, the CAI is a hold over from generations of gasoline engines... where cold air going into the engine makes a real difference. Why NOT in the diesel engine? The diesel is different. The diesel engine fires on HEAT from compression. A winter cold engine, has to run rich & gets lower MPGs. See the posts on winter "Cold Fronts". The intake air temperature at the filter is of little consequence on a Turbo Diesel where the turbo compresses the air... heating it. If intercooled, like the Cummins TD, then the intercooler is more important than the air temp at the filter. As Mike points out, the manifold heat warms the incoming charge... as it's designed to do. I'm sure there is such a thing as too warm... but we're kidding ourselves playing with air temps at the filter.It seems to me that the CAI is a hold over from gassers & not applicable to CTD. A high volume filter / exhaust system makes a lot of sense.Russ