Better winter performance though REDUCED air intake flow!!

[Hohn]

Better winter performance though REDUCED air intake flow??

Yes, that's correct-- better performance for winter operation by REDUCING air intake flow! Note, this only applies to running around empty and at light loads, not towing heavy.

I've tested this the last two winters, one with my BHAF, and now with my PowerCore prototype filter.

I've concluded that to a point, less is more.

Now, I'm not talking about a restrictive air filter. Rather, I'm talking about blocking off part of a higher-flow air unit using duct tape.

There are a number of reasons to duct tape off your intake:
1) The reduced airflow to the turbo will raise temps, and help your engine get up to temp faster, which reduces wear and helps with combustion efficiency

2) Blocking off the intake reduces the hp is takes to drive the turbo, because the the compressor is compressing air that's less dense, and it takes less work to spin through thinner air.

3) Engine is MUCH quieter-- not just turbine whine. Turbo whine is GONE completely (even w/o silencer ring), but overall engine noise is just much less.

4) For winter operation, average EGT goes up-- and this is a GOOD thing if you aren't working the engine.

5) Reducing the surface area the filter can breathe through increases air intake velocity.


With my BHAF, I duct taped off the entire thing except for a "window" about 3 sq inches (on the engine side of the bhaf to help pick up exhaust heat). It worked great-- killed turbo noise, improved winter MPG and helped the engine warm up a lot faster.

Now, with my PowerCore filter, I've taped off almost the entire 10. 5" inlet, sealed with duct tape, less a sliver of exposed filter at either side. For normal driving and hwy cruising, EGTs are well in hand, only slightly higher. I DO NOT use WOT with the setp, as the engine just can't breathe. But 15psi of boost is useable imo.

Repeat, this is NOT a setup for WOT use. It's for daily commuter usage and perhaps very light towing when the temperature start to get down around freezing.

So if you live in a Northern climate like me, and have a BHAF or AFE setup, and don't tow over 4K pounds or so, THIS IS SOMETHING YOU SHOULD TRY.

It's not for everyone, but if you find yourself in similar circumstances, there are MPG and other benefits to be had.

Justin
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[Gary - K7GLD]

JEEZE Hohn - how about an outer shield for the air filter with a trap door or slider that is throttle actuated to only open when you punch the go pedal?

 

[Hohn]

Don't think I didn't think of that already.

The problem was that the actuators (from a B1 Bomber fast-act cooling duct) were too powerful, and tended to blow off the hood when activated.

Duct tape was the next best thing.

jlh

 

[Fishin Guide]

the actuators (from a B1 Bomber fast-act cooling duct) were too powerful, and tended to blow off the hood when activated.



jlh

I thought that what the lever marked "HOOD" was for? Just pull it and it'll flood the engine compartment with cool, dense, power adding air!! :-laf



Dave

 

[Vaughn MacKenzie]

Hohn I was thinking of something similar to what you did because Cummins stated that when idling in cold weather the cold air coming into the engine is what carries heat away. Especially with the 24v since the head flows more. So I was thinking restrict the air (especially those with ported heads, cams, etc. ) to help reduce the cooling effect.



When it gets real cold I cover up my intercooler.



Vaughn

 

[Boondocker]

Hmmm. You may have just vindicated the Dodge factory air box design



Seriously though, your concept seems risky. While you might be an extraordinarly carefully driver, there is a chance that you could press on the throttle too hard and collapse the filter. Why not just go with the traditional grill cover that reduces air flow through the radiator and intercooler?



My truck always seems peppier the first minute or two of driving. I attribute this to cold air. Relatively speaking anyway, before the intercooler, turbo, and related piping get up to normal engine temp. For that reason, I'm considering a larger intercooler as my next performance mod... not anytime soon, but maybe next.



Neil



P. S.

JEEZE Hohn - how about an outer shield for the air filter with a trap door or slider that is throttle actuated to only open when you punch the go pedal?

Gary, Hohn doesn't need a fancy adjustable trap door slider dohicky. He has a flight crew, I mean pit crew, that can just rip off a piece of tape during a pit stop in under 5. 4 seconds!

 

[Hohn]

Hmmm. You may have just vindicated the Dodge factory air box design

Seriously though, your concept seems risky. While you might be an extraordinarly carefully driver, there is a chance that you could press on the throttle too hard and collapse the filter. Why not just go with the traditional grill cover that reduces air flow through the radiator and intercooler?

My truck always seems peppier the first minute or two of driving. I attribute this to cold air. Relatively speaking anyway, before the intercooler, turbo, and related piping get up to normal engine temp. For that reason, I'm considering a larger intercooler as my next performance mod... not anytime soon, but maybe next.

Neil

Filter collapse is a non-issue, at least with the PowerCore unit. The engine would explode before it could suck hard enough on the P-core to cause a collapse. The stacked-soda-straw design of the powercore makes it VERY strong in the way that it needs to be to resist collapse.

The p-core filter is taped across the metal rim-- the tape doesn't touch the actual filter element at all.

See the P-core filter pics in my gallery if you don't remember what it looks like.


Now, with a BHAF I suppose the possibility of filter collapse is more reasonable. But still VERY unlikely. This is because the force is acting on the tape (and therefore, on the metal mesh supporting the tape), not on the filter element. Thus, the TAPE may collapse, but not the filter element. The fact that there is a metal mesh grid on the outside of the BHAF is key.

If you taped over the ACTUAL filter element (i. e. , there was no metal mesh) then filter collapse could be a very realistic possibility.

I hope that I've explained how the presence of an air gap between the tape and the actual filter element means that the element simply won't collapse.

jlh

 

[Diesel Freak]

instead of runing the risk of sucking something through the turbo, use a piece of cardboard and block off airflow to the CAC!!!

 

[Devan Manis]

i tried that, it got wet and fell down to where it couldn't be reached... it sucked to dig out with two pieces of rebar and not hitting the condencer, but i got it.

 

[Diesel Freak]

That is why you use the wax coated stuff!!!!

 

[Hohn]

instead of runing the risk of sucking something through the turbo, use a piece of cardboard and block off airflow to the CAC!!!

Maybe I should have stated that this was already done?

right back at ya, babe

 

[ThrottleJockey]

Hey Hohn,



I got the factory airbox all duct taped except for a small 4 inch window next to the turbo like you did.

A piece of sheet metal as a winterfront.

Took off the fan.

No timing. (Raises EGTs)

Duct taped the Scotty II hole and the side air hole.



And I want to replace a section of my 4 inch exhaust straight pipe with a 4 inch section of pipe with a crush in the center to increase back pressure.



What do you think?

 

[rbattelle]

What about mounting a small low-power grid heater in the intake plumbing? Or install a switch to allow you to turn on one of the stock heater grids at will?



Blocking off portions of the intake goes against the principle of letting the engine breath - one that is deeply embedded in my subconscious. Breathing through a straw in winter will probably keep you warmer, but good luck doing any physical work!



-Ryan

 

[Hohn]

Ryan-- bad analogy. You aren't cooled primarily by air intake, and intake temp has little effect on your body's efficiency.

I agree that unrestricted flow of warmer air would be better, but a restriction is a cheaper/easier wayt to achieve the same overall goal.

 

[Matt400]

Maybe one of those "electric exhaust cut out" kits to bypass the intercooler would prove helpful in the winter??

 

[WDixon27]

i tried that, it got wet and fell down to where it couldn't be reached... it sucked to dig out with two pieces of rebar and not hitting the condencer, but i got it.

steal a couple cheapo reality signs and use that :-laf

 

[Devan Manis]

Good idea.

 

[WDaniels]

Hohn,

A couple of flaws in your theory.

1.

Blocking off the intake reduces the hp is takes to drive the turbo, because the the compressor is compressing air that's less dense, and it takes less work to spin through thinner air.

Your way, by blocking off part of your filter decreases air volume, not air density. If your turbine is spinning in less dense air it is spinning in a partial vacuum.

2. And as for taking more horse power to drive the turbo, it is infetisimal. The turbo almost takes no h/p to drive, the turbo is driven by exhaust pressure which is the same with or without a turbo which is what makes the turbo/fuel offset so desirable. The only reason that the turbo takes more fuel to drive is because we put our foot in it.

3. On step one, the reasons that the egt's are higher is because of reduced air flow which in real low power settings is maybe ok but if anything were to happen and you tromped on it you could do some damage, your choice.

After driving in a Cummins in the severe cold(- 69 actual is the coldest) for the last 11 years the best thing I've found for increasing heat are; 1. A 195 degree thermostat. 2. A radiator blanket, or the inserts in the grill. They are not as good but do work well. The blanket is the best thing for all engine running parameters. 3. A manual throttle or an automatic throttle to raise your RPM's to about 1250 for 10 minutes at idle. And 4 to a lesser extent an exhaust brake during warmup. One and two in conjunction with each other works well.

If anyone is interested in the radiator blanket, let me know because there is a place up here that makes the blankets for the dodges that fit perfectly around all the bumps and knobs. It has a zipper that opens up for warmer weather. I have to open mine at about -5 or above because I overheat if I don't. If you want one just let me know and I'll get one shipped to you.

Just my 2 cents worth.

WD

P. S. I take my oil bath filter (K&N) off during the winter because the oil is so cold it blocks to much air and lets dirt through because the oil doesn't flow to refill the gaps the airflow creates.

 

[Hohn]

Thanks for the post, WDaniels-- good info.

 

[nickleinonen]

yesterday while doing maintenence on my truck, i started on the path for getting ready for winter... a 300w magnetic heater [with lots of heat sink goo between it and the pan] is now bolted in place against the oil pan to help warm the oil up [block heater is nice, but when the oil is ice cold, the coolent temp will drop quick when it passes through the oil cooler] and i have a piece of ±3/8" foam fixed against the rad to block off air flow. the aftercooler and p/steering cooler and condensor still have good flow though [my foam piece was only 24" tall, so the entire rad didn't get blocked leaving the p/steering cooler at the bottom exposed to flow]



starting to get to below freezing now. . i can't wait until spring :{