Best cold air intake for 350 TBI

[great white]

did you not just prove my point that there are restrictions? and that not every vehicle is the same?

Nope and no point in explaining it further.

L8tr g8tr.

 

[bow61509]

where's tempted when you need him for his wise input on this debate?













sorry I had to.... :lmao:
carry on gentlemen

Sent from my static android

 

[narizon]

Not to be disrespectful but the truth is that for every mod that one does to his/her truck their is positive feedback & always a hater who hates.That's just the way it is Period .Now back to the the original ???'s .
I cant say much for the other brands but a Volant CAI is what I'm running & very happy with it,especially since it was new & a Craig's List Special @ a grand total of $75 smacks.Noise wise their wasn't any when first installed,very quiet.Now all I here is a si/so 3" Thrush roaring out before the passenger wheel.It is well a made unit & very sturdy.I due have a 1" TBI spacer so I did mod the fender mount to get it aligned properly.Had to raise the air box 3/4".The actual Volant air filter is large enough to almost take the whole inside space of the air box.I suppose that any brand filter will work though.I have several mods dome to the 5.7 TBI & the air supplied by the CAI is sufficient.
I have a 1972 GTO Ram Air Hood in the garage that will one day be welded on my '89 & plan to mod the Volant CAI.I think it will look Bad Ass.


Some pics of the Volant system on a 5.7 TBI

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[great white]

Ok, having being referred to as a "hater" I'll take another stab at this to try clarify some things.

There is no tone intended here or personal references/slights intended to anyone. I’m simply trying to put the info out for those who want to consider it.
Maybe pass on a new thing or two some folks out there.

But first, I'd like to get a pet peeve off my chest and state that I don't "hate" anyone or anything. "Hate" is a powerful word that is used far too cavalierly these days. Same as the word “love”. I love my wife, I love my daughter, heck I'd even go so far as to say i love my dogs....But I don't love my truck, bike, boat or house. They're just objects. I may like them a lot, but if they burned to the ground tomorrow I'd just go buy another and be equally satisfied. A little sad and a bit poorer in the wallet maybe, but no big deal in the greater scheme.

So, with that out of the way; my disagreement comes from my experience and education of what happens in an engine, not a belief, impression or dubious sampling techniques.

So we all know I’m not some jablony just spouting off, here’s a brief resumé:

I've worked in automotive and aerospace for the last 3 decades. I'm University educated in mechanical engineering, an ASE certified technician, a licensed AME and have been designing, rebuilding and operating aircraft propulsion systems (J85CAN40, T58, T700 to name a few) longer than some have been alive. I've worked on terrestrial diesel and gas engines, plus both both recip and turbine (radial and axial flow) aviation engines, dealing with all extremes of climate and operating conditions. I am currently qualified flight crew in the RCAF. I'm not a pilot, I'm a Flight Engineer (too smart to be a pilot! LOL). I felt the need to get out and do something a bit more "hands on" and make a difference in the world besides my earlier theoretical and behind the scenes work. I’ve also raced motorcycles (err, maybe that should be crashed high rate of speed motorcycles!), dabbled a bit in off road rally and was (but am no longer) and avid offroader who’s popped more diff’s, bearings, ujoints and other components than he’d care to admit. I'm also qualified to operate everything right up to 80,000 pounders civy, and a heck of a lot more military...

To say I'm qualified to speak a bit on the subject of engine performance is reasonably accurate.

This is going to be somewhat long and involved, so right now I’d recommend you either grab a coffee or stop reading and bail out to the next post if you don't feel like reading a lot and doing a reasonable bit of pondering.


There are also going to be a lot of aerospace references, mainly because they're written for pilots so they're easier to understand.




(just kidding for the aviators in the crowd, we all know what I'm on about!)

If you disagree that’s cool, but I’m not going to debate it any further than this huge post I’m already typing. Accept it or reject it, it’s up to you. I’m not looking for a debate. I’m only putting the info out there.


Keep in mind, this is only to illustrate why "cold air" is better than” free under hood air”. There are many other variable in play, but we’re only looking at the variable of temperature and it’s effect here.

Let's begin:

Atmosphere is 21% O2, 78% N and a smattering of other gases. It's this 21% we're interested in. This is what makes combustion possible. This 21% never changes either. Temperature, altitude, etc. Always 21%. It’s because it’s a %, not an absolute number.

In order to change the percent, you have to add supplemental O2. (This is why N2O works they way it does, as well as it’s cooling effect = density!).

So what you say?

Well, it's the density of the air we want to look at and percent O2 is relevant to understanding that.

While we can never get more than that 21% by volume of air without adding supplimental O2, we can change the density.

And density is what an engine cares about. You can ease the route into the engine by blending ports and whatnot, but it pales in comparison to density.

That is why you can never match forced induction with a NA engine. Density. That is why forced induction uses such convoluted tubing under the hood to cool compressed air. All those 90* turns, forcing through intercoolers, hitting in with WMI.... It lets the compressor cram just that much more O2 in the cylinder per valve event.

And make no mistake; the real limiting factor is the valve event. It will only pass a given volume per event. Density is how you get more O2 into that volume.

On a forced induction engine, the compression effect get’s more O2 molecules in that volume, on a NA engine you have to do it with temperature.

Density.

Let’s explore that a little more to help illustrate the point.

We all know (or have heard of) Boyle’s law. Volume-pressure- inverse –temperature - constant….yadda yadda yadda…..

Less are familiar with Charles law in that volume is proportional to temperature.

To spare the university lecture, you can fit so many molecules in a container at a certain temperature.

Here’s a theoretical example. I’m not going to go through calculation to get the exact figures, this is for illustration of concept only:

Say we have a container that holds 20 molecules of O2 (remember that there’s lots of N in there too) at 10 C. Molecules are not static, they’re moving and bumping around in there. That’s a function of the energy from the heat. So in addition to the space for the actual molecule, you need the space for the movement.

Now let’s double the temperature to 20 C. The molecule is the same size, but now it moves around twice as far/much from the added energy.

If they move twice as much, you get half as many molecules in that given space (i.e.: valve event for those who are connecting the dots).

Your 20 molecules of O2 just became 10 molecules. So when you intake valve opens it only passes 10 molecules for it’s fixed volume vice 20 at a lower temperature. Now you have half as much catalyst (O2) to burn with the fuel in the chamber; which means you end up dumping some of those fuel molecules out the exhaust valve in an unburned state (unless you’re FI, in which the PCM cuts back on the rich condition it sees by removing fuel and cutting power production all the same), which leaves performance on the table.

Or, the increased temperature increases the pressure if it’s a sealed container.

In this discussion, we’re talking about engine intake systems prior to the intake valve (i.e.: not sealed), so that doesn’t apply. The only sealed container is the cylinder once the valves are closed and the intake tract is immaterial at that point.

So for our purposes of density and “warm air intakes”, if you increase the air temperature you get less O2 per volume. IOW, the density decreases and it decreases a lot.

Let’s look an aviation example of engine performance since it gives us a nice convenient chart to look at and no one disputes the fact that the higher you go, the less you engine performance is:

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Aviation references everything off a standard ICAO day, 15C and press 29.92.

We’ll assume the atmospheric pressure is constant for this example and look at temperature effects on density.

So, starting on the bottom line, let’s look at a 20 degree day, or for our purposes and 20 degree engine bay.
If we enter the chart and go to 1000 feet (about the average level of most of the great plains), we see the engine thinks it’s at about 1600 feet. Not too bad, 600 feet isn’t a huge jump and engine performance is still good.

But…….

Now we need to consider that the engine is operating and the intake is in the path of the cooling system. Your cooling system is designed to hold the temperature approx 90C ( or 195 F if you prefer). No one would argue if the cooling system wasn’t there it would overheat at even an idle (gas engines, diesel is a different story).

For arguments sake, let’s say your cooling system imparts a delta of 5 C (40F) to maintain temps around 195 F. not an unrealistic number. That heat is shed from the radiator and raises the under hood temperature by a similar amount.

Now lets see what that does on the chart.

Enter at 25C, go up to 1000 ft….holy momma. The engine now sees 2400 ft density altitude! 1400 ft higher! That’s a significant effect for engine performance.

Believe me, operate a helicopter and you’ll understand. Very significant indeed.

But wait, we’re not done yet; there are lots of other heat sources under the hood:

The block radiates heat, the heads, the exhaust manifold are a huge contributor, and on and on….under hood temps have been known to melt plastics when run really hard.

But let’s be conservative and say radiant heat in the engine bay is only about another 40 F delta (5C). If you’ve ever stuck your hand close to a warmed cast iron exhaust manifold, you’ll know what I mean by conservative.

So now we’re looking at a total under hood temp of 20 (ambient) + 40 (radiator) + 40 (radiant) or 80F (approx 27 C).

Chart please….

Approx 2700ft.

Yeah, that’s getting bad.

Now start working the number s if you’re dealing with higher ambient and great delta’s with shed under hood heat. It gets really bad really fast.

Now, consider all you have to do is put a piece of (relatively) thermally neutral plastic pipe to bring in that high pressure ambient 20 degree air at the nose of the vehicle and regain that 1700 ft attitude loss and the denser air that goes with it…..

You can spin the numbers for sea level or 5000 ft, doesn’t matter. Cooler air trumps warm every time.

Don’t even get me started on how many more negative effects warmer intake air has on FI vehicles when chasing that HP. See that intake? See that sensor? It measures Intake Air Temperature and does lots of neat things way down deep in the PCM with compensation charts and multipliers and they all involve removing fuel and effecting spark timing…..

The only time an engine benefits from warm air is during cold operation (ie: not up to operating temps) or in when carburetor icing is a concern, such as in high altitude operation (ie: 20,000 ft). Icing can be experienced at normal altitude though, given the right conditions and configuration.

People often point to things like it sounds faster or feels faster when operating an open element under hood when what is actually being experienced is the impression that the engine is working better. Close the hood, stick it on a dyno and the truth will be revealed.

Keep installing open under hood air filters if you like them, it’s a free world and I guess the do kinda look cool at the local fast food joint parking lot but they’re not going to make more HP than even a half decent sealed intake system to ambient air. They sure make the engine sound fast from the passenger compartment as they whoooosh on down the road though...

That’s a lot of typing and getting it all down in one shot so don’t do the “Bill Nye Science Guy” thing and start trying to pick it apart. There are lots of generalizations in there and maybe a few numbers errors. It’s pretty hard to write a completely accurate long post in a 3 inch box on a screen.

Like I mentioned earlier, think about it and accept or reject.

Your choice.

Makes not a lot of diff to me after now putting the info out here for all to consider. I know what I’m doing to my vehicles, what you do to yours is your choice...

Now that my fingers are sore from all the hunt and peck typing, I’m gonna go have a fresh coffee and a donut and finish writing the briefing note on suspect causes for breaking off turbine blades in the power turbine section of our GE T700/CT-7 engines.

I really should get one of those dictating programs……

Cheers

 

[TylerZ281500]

i thought you said you were done and there was no point in explaining it? you a very very confusing man sir

 

[great white]

i thought you said you were done and there was no point in explaining it? you a very very confusing man sir

Yawn.

Not getting drawn into something with you bub.

have a nice day.

 

[TylerZ281500]

i mean once again you provoked it. ur like the kid that runs away from everything till he has some witty comment later on when the debate is long and over

pretty sure you werent called a hater either, u just took it as he called you that. his statememnt was generalized, for every mod someone does totheir vehicle their will be people who like it appreciate it and want to do it or a version of it as well. then their are those who get their panties in a wad because they dont like it, think they know its not any good or have some sort of jealousy issue.

 

[95Escahoe]

Lol didn't think this would turn out this way

Sent from my HTC One X using Tapatalk 2

 

[TylerZ281500]

http://www.s10forum.com/tbi_cold_air_intake_how_to

you could go cheap and use a bonnet like that, tubing can be made from metal, plastic, or pvc, couplers can be had at silicone intakes.com or jegs summit etc. and your filer can be bought wherever depending on what one you wnat to go with. id gut the fender stuff, and make a plain and simple box out of sheet metal and rivet it to your fender. then get some weatherstripping and run it wround where it will seal off when the hoods shut. cheap weatherstripping you could find some used rear hatch seal from an 92-92 camaro/firbird and thatd give you enough length to do it a few times if you mess up.

 

[great white]

i mean once again you provoked it. ur like the kid that runs away from everything till he has some witty comment later on when the debate is long and over

pretty sure you werent called a hater either, u just took it as he called you that. his statememnt was generalized, for every mod someone does totheir vehicle their will be people who like it appreciate it and want to do it or a version of it as well. then their are those who get their panties in a wad because they dont like it, think they know its not any good or have some sort of jealousy issue.

Lol, you must be a politician or practicing to be one.

Can't compete on facts or the issue so move on to character assassination.

Too funny.

My post had to do with explaining why a "cold air" intake was beneficial and had nothing to do with you.

Then you took it upon yourself to start something with a witless comment.

My response is I'm not getting into it with you in an attempt to end the....well, to end it.

But thats not good enough so you follow up with another prod with the above outright insult.

Someone is provoking/prolonging this, and it is not me.


Now, in the interest of getting this gents thread back on track, let this be the end of it...Stay away from me, i'll stay away from you and everyone's happy.