Wow...
So you can make something less dense by compressing it. Learn something new everyday I suppose.
Proven Daily Driver Turbo/Injector combos
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Wow...
So you can make something less dense by compressing it. Learn something new everyday I suppose.
Well this is what I get when I post while working.
Compressing air makes it hotter and obviously increases density. However, the heat of the air (due to ambient temperature and the compression from turbos) means it will not be as dense as it could be at lower temperatures. I'd imagine at some point there is a trade off - the efficiency range Trusted spoke of.
Which is precisely the point of compound setups in the first place. Each stage runs at a nice, low PR.
Higher boost pressures (compressor efficiency constant) results in higher temps yes, lower density, not possible.
The only trade-off that comes into play is through the pumping losses associated with driving the turbine that is powering the compressor(s) to make this pressure.
If not we would all make the most power at the summit of Mt Everest where the air pressure and temperature are far lower than anywhere in the US.
Another reality check might come in the fact that all the highest specific powered diesel engines make use of multi-stage turbocharging.
So I've done some reading on this over the last 30 minutes and I feel dumber.
It seems everyone can agree that the less dense the air (whether due to elevation or heat) means a turbo has to work harder (i.e., spin longer/faster) to produce the same power one would have with cooler, more dense air. This has to be the lower power feeling people get as their trucks don't perform as well in high temperatures or at high altitude. High altitude and high temperatures would be the worst.
My original thought process was that if warmer air is less dense, then further compressing air (thus adding heat) must be counter-productive to making the air more dense. It's obviously not a strong effect, otherwise there would be no point to turbocharging at all. So, I think I've convinced myself that even if compounding does add more heat to the air, any effect the heat has on the air density is overcome by the charger compressing the air. Does this sound right?
It seems everyone can agree that the less dense the air (whether due to elevation or heat) means a turbo has to work harder (i.e., spin longer/faster) to produce the same power one would have with cooler, more dense air. This has to be the lower power feeling people get as their trucks don't perform as well in high temperatures or at high altitude. High altitude and high temperatures would be the worst.
My original thought process was that if warmer air is less dense, then further compressing air (thus adding heat) must be counter-productive to making the air more dense. It's obviously not a strong effect, otherwise there would be no point to turbocharging at all. So, I think I've convinced myself that even if compounding does add more heat to the air, any effect the heat has on the air density is overcome by the charger compressing the air. Does this sound right?
And since our power comes from the oxygen molecules in the air, further compressing air just adds more molecules into our engines. The ambient air density has an effect, but once it gets into our engine - the power output of a given volume of air is set.
Temperature is a byproduct of air compression but does not have an effect on the charger's ability to compress air - other than if the turbo were to get too hot and fail.
So in summary: my original post was wrong.
Temperature is a byproduct of air compression but does not have an effect on the charger's ability to compress air - other than if the turbo were to get too hot and fail.
So in summary: my original post was wrong.
Yeah I figured out too late that I should've not bothered with explaining what I was originally thinking. I had to go down a long path to get my head straightened out.
The bottom line is this (which maybe y'all already knew): the temperature of the air as a function of compression doesn't negatively affect power. Ambient temperature does affect power and so does elevation. Any temperature increase/decrease not from the turbos (e.g., intercoolers or just engine heat) can have an effect.
There. I'm done. If a mod happens to come across this, feel free to delete my earlier posts.
The bottom line is this (which maybe y'all already knew): the temperature of the air as a function of compression doesn't negatively affect power. Ambient temperature does affect power and so does elevation. Any temperature increase/decrease not from the turbos (e.g., intercoolers or just engine heat) can have an effect.
There. I'm done. If a mod happens to come across this, feel free to delete my earlier posts.
Trusted
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If you are using compounds in their efficiency range. The 6.4 system was never designed to handle the boost pressures they are producing. As such, they are outside of their efficiency range. A larger or different configuration would yield the same power with less boost.
FaSSt9602
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Now I do understand the efficiency range of turbos and all, but what I have a hard time grasping is, and I know there is probably a simple answer...
Isn't boost basically restriction?
I know larger systems ie, stock vs. say a 62, 64, or 66 can generate more cfm while still staying in their respective efficiency ranges, but how can you generate more cfm with less boost and make MORE power, all other things being equal? So how can a 62mm turbo that builds (for the sake of argument) 30lbs of boost make more power than a stocker that builds 30lbs of boost? The heat created by the stocker being on the top side of its efficiency range can't make that much of a difference can it?
A straw can only flow so much "cfm" when you blow through it, and the only way to increase the amount of air is to blow harder (more boost), or get a McDonald's straw (less restriction). So wouldn't the only way to really utilize the additional cfm of a larger charger require reducing the restriction in the stock intake/heads?
Trusted
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Ok, so I just spend the last 25 minutes answering this question and realized that I wrote a novel with way to much information that doesn’t mean anything to those not doing this for a living. So, to simplify this, boost is generated in the compressor wheel/cover. Engine restriction plays a roll in it, but the compressor wheel/cover relationship is the biggest determining factory to boost and cfm.
That is why a larger turbo will produce more cfm than a smaller turbo
That is why a larger turbo will produce more cfm than a smaller turbo
FaSSt9602
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Since this is a turbo and injector thread, Trusted and Doug, in your thread "high volume high pressure oil pump" you guys get into some pretty technical stuff with injectors, talking about internals and posting cad drawings that goes way over my small head. What is it about similar "combos" that work so much better than others?
There are a ton of posts about so and so's 190's having a ton more fuel than the next but what's the difference? I know without side by side, same dyno comparison it is impossible to really compare, but what makes a "combo" work?
There are a ton of posts about so and so's 190's having a ton more fuel than the next but what's the difference? I know without side by side, same dyno comparison it is impossible to really compare, but what makes a "combo" work?
Trusted
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There are a lot of different parts to an injector. Depending on how they are modified will depend on how they work. Since there is no set standard, then they all work differently.
In addition to this, some manufactures have lots of different sizes, but really only make a few different one. They sell you the closest one to that size. So, a 190 may be a 200 or a 175 may be a 190 or something along those lines. Then you have the couple manufactures out there that don’t know how to modify the injectors properly and sell 225’s that really only flows much less.
Even if you have two injectors that flow the same (lets stay with 190), if they have different nozzle sizes/hole configuration, they will have different tail pipe emissions. Performance may be close to the same for most of the rpm range, but the consumer’s perspective of the one with larger nozzles is that it flows more fuel, when in fact, it is flowing the same amount, just not as efficient.
As far as turbos, there are just a couple true manufactures (BorgWarner and Garrett are the two largest). From there, you have a lot of smaller companies that make pieces (compressor covers, turbine housings are the most common). Depending on who the manufactures (company putting the kit together not OE) supplier is, will depend on what pieces they have access to and what combination they can put together. Most of us have the same access to compressor wheels and covers and use the same stuff. We, also, have access to the same turbine wheels but there is a widely verity and many use different versions with the same specs (which yield slightly different results). The turbine housings for the 6.0 chargers vary greatly. This may be because of availability of parts, may be because of ease of manufacturing kits, may be the lack of testing, or who knows what else. But all said and done, you can put together a much wider variance in chargers than you probably can in injectors. With turbos, you can get the specs and actually do some comparisons. With injectors unless you have a test facility or send them out to be tested before you install them, the size is what the manufacture says it is, which may not always be the case.
In addition to this, some manufactures have lots of different sizes, but really only make a few different one. They sell you the closest one to that size. So, a 190 may be a 200 or a 175 may be a 190 or something along those lines. Then you have the couple manufactures out there that don’t know how to modify the injectors properly and sell 225’s that really only flows much less.
Even if you have two injectors that flow the same (lets stay with 190), if they have different nozzle sizes/hole configuration, they will have different tail pipe emissions. Performance may be close to the same for most of the rpm range, but the consumer’s perspective of the one with larger nozzles is that it flows more fuel, when in fact, it is flowing the same amount, just not as efficient.
As far as turbos, there are just a couple true manufactures (BorgWarner and Garrett are the two largest). From there, you have a lot of smaller companies that make pieces (compressor covers, turbine housings are the most common). Depending on who the manufactures (company putting the kit together not OE) supplier is, will depend on what pieces they have access to and what combination they can put together. Most of us have the same access to compressor wheels and covers and use the same stuff. We, also, have access to the same turbine wheels but there is a widely verity and many use different versions with the same specs (which yield slightly different results). The turbine housings for the 6.0 chargers vary greatly. This may be because of availability of parts, may be because of ease of manufacturing kits, may be the lack of testing, or who knows what else. But all said and done, you can put together a much wider variance in chargers than you probably can in injectors. With turbos, you can get the specs and actually do some comparisons. With injectors unless you have a test facility or send them out to be tested before you install them, the size is what the manufacture says it is, which may not always be the case.
Dusty's Diesel
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Alot of the companies injectors are putting out what they say, as far as cc's. However they are not getting it all in there in the amount of time that they have. Thus squriting fuel in after the combustion has already taken place. Producing smoke and a lack of power. That is why you can take one companies 225 or 250 which is putting out that much if not more fuel. And take another's 190's or 200's and make more power w/ much more driveability and half the smoke.
dukcaln
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Two words that will fix your conception. Temperature for starters, and ultimately, MASS.
And no, boost is not restriction, it's pressure. If you had ports the size of your cylinder bore you would still have boost because the compressor is moving more air than the engine is displacing.
As to this:
First and foremost, you need to understand that CFM through any given engine for any given rpm NEVER changes... Read that again... no matter what boost you're running the CFM flow through the engine itself NEVER goes up, down or anywhere else as long as the engine is turning at ____ rpm. This is because the engine literally displaces ___ cubic inches every two revs at __ VE. That's the engine's physical displacement, times the actual VE achieved with the current valving, head ports and cam profile.
Now you can change that VE, and increase it by altering runners, valve sizes, unshrouding valves, cam profile changes, intake manifold design changes, exhaust manifold changes, reductions in drive pressure, so on and so forth. "Airflow" improvements. THAT will produce a higher VE, and subsequently make the "straw" bigger as you stated.
However, manifold pressure itself, has no effect. The engine moves the exact same CFM at 5lbs of boost as it does at 500lbs of boost. It must, the cylinders don't get bigger, nor does the crankshaft stroke grow longer with added boost now does it? Of course not. The additional "air" gained with increased boost is through air Density, not flow. You're flowing the same volume of air, same number of cubic feet every minute, it's just that each of those cubic feet now weigh 2, 3, 4 times what they used to. The net effect is that you just put 2, 3, 4 times as many oxygen molecules through that engine every 60 seconds all else constant.
As I said, temperature and mass were missing from what you stated above. 30psi on any given engine at 300 degrees is a hell of a lot less oxygen than 30psi at 70 degrees. And that's the main reason a larger turbocharger can make far more power at the same manifold pressure when it's operating in a more efficient region of it's map when compared to say a stock charger being over-driven for the same manifold pressure.
The second advantage usually comes in the form of decreased drive pressure from a larger turbine wheel/housing. At that point you're not only delivering more air density to the intake, but increasing VE through reduced cylinder reversion on valve overlap.
Temperature. Mass. Ultimately density. Density is what allows more power per lb of boost holding all else constant.
EDP
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This whole paragraph can be summed up real quickley.
It should not take 11 turbo's to reach what many have reached the first go round.
Our speced out Precision built turbos do not see these drive pressure numbers or concerns of waste-gating.
A PRECISION BUILT new super secret turbo from us can do all this all while cleaning up injectors larger then 190's. Smoke free and no need for a big stal or manual trans. Its amazing what the correct setup can do. Not to mention how much money can be saved and put towards things like tires and lockers. But then again when a vendor needs to make rent anything to sell parts works better for number 1
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EDP
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Ask him to show ya pictures of his twin setup he was running..... pretty interesting if you ask me.
Dusty's Diesel
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EDP
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where not laughing with you we are ALL laughing at YOU:bang