The coffee probably hadn't kicked in yet. I've had those mornings

 

Gentlemen, I am new to the diesel community so please do not bite my head off for chiming in. By the way, I have read the entire post to include the awesome articles from the turbodieselregister. Here goes, I personally despise aftermarket intake systems. They are completely overpriced and "Marketers" publish claims that they make unreasonable power. In the Drag Racing community, both boosted and non boosted, I have seen the best gains by using "Open" air intake systems. Now, in the "Daily Driven" world you would think that this is not an option. You are wrong. What I am about to say has not been attempted on my diesel tuck, only on high HP gas applications. For street driven "Race" cars I have always used Panty Hose as an air filter. Not the actual leg portion but the crotch area where the fabric is doubled up. I use either a clamp or a very strong rubber band, depending on engine temps. To make a little stronger, place a small amount of "EPOXY" on a couple parts of the rubber band. Problem is this, it needs to be changed quite frequently. TESTING, there has never been an article to duplicate what I have said. Plus it looks like crap under the hood. I can tell you this though, when cold air is around, hold on to your britches because there is no better way to feed air into the engine. You could even fabricate your own "Ram Air" by filtering it in an alternate location. Hope this helps. Again I am new to diesel so stand by for future posts to provide results.

 

I LOVE it!!!!!

Innovation at its best!!! Now one CAN have a valid excuse for buying panty hose that won't lose you your man card.

 

IMO, the stock air cleaner does the best job actually filtering the air also. Every company claims that they filter 99.7% compared to stock, but they also claim 30 and 40 hp gains. BS! I used to run an AFE stage 2 with the Pro Dry and also tried a PG7. Each of them left a slight haze of dust in the tube. The stock design is great for stock engines and slightly modded, heck they even through a baffle in there to make it nice quite for ya.(AFE sounded like a **** 747 on the highway)

With the items in my signature I can get right at 20mpg h.c. also at 70. Get a smarty of some flavor, would recommend Jr if you want you stock TC to last.

Someone really needs to create a modification beginners sticky highlighting the issues and gains.

 

Aw Heck! But then we'd have nothing to argue about......

 

Read them all plus about a dozen more that actually test air temps in real world situations. The reality is hot under hood air effecting power is not a factor. While said tests are valid and they make a great point around flow and filtration, any discussion around heat soak and hot induction air is moot.

Last time I checked I use my truck rolling down the road and pulling loads on the road, NOT on a dyno in an enclosed shop with no air flow created by a moving vehicle. HUGE difference when it comes down to real world applications.

Anything over 20 mph the underhood temps are with 10 degrees of ambient for the most part, at times less than ambient due not being in direct sunlight. To anybody that cares, THATS what is important.

Everything you say is true when it comes to a naturally aspirated motor. Not so true when dealing with inducted motors, anybody that has done any racing knows this.

Go open the hood of your truck and look at the exhaust manifold, that spinny aluminum and cast thing hanging there is an air induction device. It negates the bulk of the air density differences naturally aspirated cars deal with. You have to compare apples to aplles for things to make sense.

The real fact is a $75 AH19037 filter and an Outerwears cover will provide the same performance as a $300 system with all the shields, bells, and whistles WHILE filtering better. A stock filter in a stock box with more air access will do the same thing up to a point.

So, yes we LIKE the BHAF as we cruise down the road at 70 mph towing our 20k loads.


Its not a matter of believing you, its a matter of you not having all the facts and experience some of us have. No problem though, hang around and ask questions and you will get there eventually.

 

I use panty hose on the intake and keep a spare bra in the backseat for emergency fan belt repair....

At least that's what I told the wife when she found that stuff in the truck....

 

OK then. I'm keeping the stock intake except I took out the baffle and silencer ring. But the Fram filter is gonna have to go. After spending $1000 for new tires, I'll be saving for a Smarty Jr. and a 40" Donaldson muffler. That was alot of good info. Thanks again for the input.

 

Interesting points no_6_oh_no ...

From what I understood, most good good dynos use huge fans to simulate the moving air and CFM requirements of the machine at speed. Is that not the case? Regarding real world test results being different than dynos, could you provide sources for those real world tests? I would be interested in reading results of real world underhood temperature tests at road speed.

I was also under the impression that ANY heat for a motor is not good for making maximum power, and it doesn't matter if the motor is normally aspirated or forced air induction through either a supercharger or turbo. The only place where power is not affected and it is advantageous to have forced air induction is in high altitude situations. Again I was taught that ANY air intake heat is bad - doesn't matter if it's got a turbo or not.

Not trying to start or (continue) an argument, but a healthy educational discussion

 

Think about how large a fan it would take to simulate 20 mph, 40 mph, or even 70 mph. Thats a wind tunnel not a fan.

You can blow a little air at the front of a truck but its not going to very representative. Most of the dynos I have run have a couple fans to clear the air so you don't choke, thats about it. What about the tow arounds and doing the run outside?

Its been years now but the underhood heat thing was big back in the day. If you searh on here, TDR, and other forums that escape me several people did test by mounting temp sensors under the hood and drove different speeds to see what the temps actually did. Not very scientific but the general theme repeated itself, the temps were pretty close to ambient once you were rolling down the road.

You have to remember dyno results are simply not indicative of every scenario and what you actually see out of the shop. They are a tool to decide if the changes yopu made are going the right direction and comparing different items that do the same thing. Use the info to decide what may or may not help but the results are seldom absolute across the board.


While it is true the warmer the air is the less dense it is what I meant when saying an inducted motor overcomes a lot of the issues a normally aspirated engine has. Yes, the compressed air is going to be warmer than ambient pressure air but it has more oxygen and thats the key. The air temp under pressure is not as critical as it would be at ambient.

In a diesel the air temp is even less critical because of the BTU's in the fuel and how they are used. You don't get detonation from diesel as it doesn't evaporate like gasoline so you can run a lot more heat on the intake charge with no issues. Also, in turbo motors the combustin charge is used to spin the turbo and thats all about how warm it is and the expansion. The cooler the charge the more energy that is wasted to warm the incoming charge to combustion temps for both exhaust flow and power. Your essentially taking away BTU's that can translate to HP by having too cool an intake charge. The IC's on these trucks are pretty good and for all but the most extreme cases intake air temp at 150-160 degrees works quite well.

Take a look at the Banks Sidewinder project and some of the things they did there to set the speed records and eek all the HP out of the motor they could. To get all th epower they could they used ice water in air to water secondary intercooler to take the IC produced temps down another 30-40 degrees to around 120 intake temps for the best results.

Truthfully, in a street driven truck at less than full HP and boost would 30-40 degrees of intake temp make a measurable power difference? Its an interesting discussion to have but trying prove\disprove gets to be really hard to do.

 

Exactly what I was trying to say. If you guys are building a race truck then all these things matter. In a daily driven street truck that doesn't get abused it's really not worth all the bother. Sure you want the truck to breathe better but worrying about a few degrees of underhood temperature is really a waste of your energy...

 

I'm just a newb trying to learn here, so be gentle with my ignorance. I have been reading this thread and went out and looked at my truck.

I don't know the differences in the stock air intakes between all the different years, but my stock box is sealed to a hole in the fender wall, so little or no air warmed by the engine is getting sucked in.

Granted, the seal between the box and fender is cheap foam and could be upgraded.

Based on the popular opinion (or not so popular, depending on your views)that cold air is better (understandably negligable for DD's) am I crazy in thinking that you could just increase the box and tube size and get more, non-engine warmed air into the engine through the pre existing hole? Maybe enlarge the hole in the fender if you're really crazy about it?

Many of the aftermarket CAI's and BHAF's I've seen leave the filter in the corner of the engine compartment with no connection to suck in cold air like the stock. I understand many do come with a box, but a lot don't and they're still call "C" AI's.


In terms of "cold" wouldn't stock be better? Am I missing something?

 

What you are suggesting would work but I think it's just easier to open the bottom of the box and use some cheap tubing to make a sort of Ram Air System. Either way will help things....

 

In essence adding a second hole to the intake box? Would you block the stock hole?
I like it....

 

You do not mess with the stock intake location. You either "Swiss Cheese the bottom of the airbox OR take a holesaw and make one big hole in the middle of the floor of the box and then fabricate some piping leading down to the bumper area where it can breathe fresh air...