Cold air intake? - PeachParts Mercedes-Benz Forum

Cervan · #1 10-17-2007, 11:52 PM

Quote:

Originally Posted by Craig

OK, let me try. The reason colder inlet air is more efficient has nothing to do with the amount of O2 available for combustion. You have to think of an internal combustion engine as a thermodynamic air cycle, all the fuel does is provide the energy to heat (and expand) the air. The maximum efficiency is obtained by having the maximum density difference between the cold inlet air (that must be compressed) and the heated air that provides the pressure during the power stroke. The net energy generated by the engine is really just the difference between the energy obtained by the power stroke and the energy required to compress the air. That is why inter-coolers provide higher efficiency on turbo-charged engines. End of Thermodynamics 101 class.

.. when a diesel spews black smoke.. that means there is no oxygen left to burn and fuel is being dumped out the tailpipe unburnt. and for one, the color of the plastic does not matter under the hood. a white pipe and a black pipe will generate the same ammount of heat Covered. it is only Light waves that cause more heat because black absorbs all the spectrum. where as white reflects all. Secondly. look where your turbo is. its right infront of the raidiator... and where does all that hot air go? it doesnt dissapear after it goes through the raidiator. it goes right past the turbo. and thats not to mention the reduced air filtering capabilitys of this crap ass filter. Third. the factory intake is a cold air intake, i dont know why anybody would put something like this on there car if they allready have one.

Mister Byrnzoil · #2 10-18-2007, 12:56 AM

Quote:

Originally Posted by Cervan

.. when a diesel spews black smoke.. that means there is no oxygen left to burn and fuel is being dumped out the tailpipe unburnt. and for one, the color of the plastic does not matter under the hood. a white pipe and a black pipe will generate the same ammount of heat Covered. it is only Light waves that cause more heat because black absorbs all the spectrum. where as white reflects all. Secondly. look where your turbo is. its right infront of the raidiator... and where does all that hot air go? it doesnt dissapear after it goes through the raidiator. it goes right past the turbo. and thats not to mention the reduced air filtering capabilitys of this crap ass filter. Third. the factory intake is a cold air intake, i dont know why anybody would put something like this on there car if they allready have one.

Ignorance truely is bliss.

I don't know where to begin to deal w/ that mess I just had the displeasure of reading, but perhaps you'd like to take a lesson from the silver portion of my stock hood pad??

Congrats... you just made the ignore list, along w/ ineon and that guy who never changed his oil... you're in good company.

Mister Byrnzoil · #3 10-18-2007, 01:13 AM

Theres no such thing as 'cold air' in a uniflow head situation...

I'll quote FI...

The exhaust proximity isn't much of a problem. It's a uniflow head, the intake ports share the same walls with the exhaust ports, the intake manifold is attached to a 180*f cylinder head and the air is 200*f+ at 13psi.

from this link...

Butchering the intake - part deux

Post #43 of that link shows the temps of the intake manifold... draw your own conclusions.

Hatterasguy · #4 10-18-2007, 01:18 AM

We can argue theory all we want. I want to see dyno sheets. Intake air temp readings would be nice as well.

Any mod that doesn't show on the dyno is a waste and rice.

Are intake temps changed? If so by how much in what conditions and RPMs?

Is power increased, or the same? Torque? If so where in the power band?

I suspect gains are zip because the turbo would force enough air through just about anything. You may gain slightly faster turbo spool up; you will gain a lot more noise!

Hatterasguy · #5 10-18-2007, 01:24 AM

http://www.youtube.com/watch?v=VEqQbdf5RMI

Dyno's don't lie excuses walk.

Old300D · #6 10-18-2007, 01:59 AM

Quote:

Originally Posted by Mister Byrnzoil

Ignorance truely is bliss.

I don't know where to begin to deal w/ that mess I just had the displeasure of reading, but perhaps you'd like to take a lesson from the silver portion of my stock hood pad??

Congrats... you just made the ignore list, along w/ ineon and that guy who never changed his oil... you're in good company.

Wow. Hard to face the possibility your "cold air" intake may not be delivering what you'd hoped...

#7 10-18-2007, 05:42 AM

Don't forget that most of the energy consumed during compression stroke is released on the rebound stroke.

That's pretty sad if you add somebody to the ignore list simply because they pointed out a flaw in your logic.

rwthomas1 · #8 10-18-2007, 06:54 PM

The interesting thing about these little discourses is that some posts walk right up to the line of calling someones car or opinion crap, just shy of the moderators rules. The result is someone getting offended and the ignore list is the only recourse available. Unfortunately, this doesn't really add to the discussion either. I submit that before posting something you consider the appropriateness of the statement if it was given face-to-face. Things said in text often lack the nuance of the same phrase given with a smile. I have had several postings directed at me that would have resulted in new and interesting bruises for the author were they in range. Unfortunately the ignore list works, but again, doesn't fix the issue or add to the discussion.

I own an intake like this that was homebrewed. The K&N I used is much larger. The oil separator is much larger and better designed. The reason for doing this? I couldn't stand replacing another set of rubber air filter mounts and the racket that big filter makes when they are shot. I think I have 30K on the homemade intake and I am very happy with it. I don't give a damn if it adds or detracts from performance. The difference will be negligible either way. I wouldn't call it "rice" as it isn't on an Asian vehicle, it has a purpose other than looks, and its not claimed to increase performance.

RT

ConnClark · #9 10-18-2007, 07:40 PM

There are a few cases where heating the air actually helps after you compress it, such as a Brayton cycle with thermal regeneration .

A diesel is different however cycle however. Diesels get more efficient with the more excess air they have inducted into the cylinder as more energy goes into heating the working fluid instead of the cooling system. This results in a higher BMEP or in other words more power to the wheels.

For the same reason, a cooler intake charge of the same mass will also result less loss of energy to the cooling system and result in a higher power output.

#10 10-18-2007, 07:54 PM

Quote:

Originally Posted by ConnClark

There are a few cases where heating the air actually helps after you compress it, such as a Brayton cycle with thermal regeneration.

Agreed, but the key is that all the energy addition happens after compression (at the "top" of the cycle). I can't think of any case (in a cycle using compressible fluid) where heating the low pressure process fluid would be an advantage.

babymog · #11 10-18-2007, 09:47 PM

Quote:

Originally Posted by Mister Byrnzoil

Ignorance truely is bliss.

I didnt nead tu reed frthr then thss.