Turbocharger Sticky

[Heretic]

-Removed at request of user-

[M_Power]

Thanks for all the info, i learned a lot of things about forced induction that i didnt know.

[Heretic]

I kind of hope this creates specific questions, and can be used to educate some of our members. I had considered going into specific tolerances, but decided to keep to the basics instead of overloading everyone

[Camaro325]

so why does the subaru wrx STI utilize the water spray into the intercooler when the computer feels the need for the intake to be cooled down....? is it bad then? thanks

[Cooper "s"]

I dont know what exactly to ask you because you don't make sense. You understand the basics of a turbo but you lack knowledge fluids and your explanation is not concise. You are just confusing the members in trying to explain something i believe you dont understand how it truly works. I know you were only asking for questions, i did not want to start an argument disregard my post but just read more into the topic before you post a technical discussion.

[Car_buff]

^^^ oh snap


do you know any better? before this goes out of hand, please, try your hand at this, and explain the basics of turbocharging to u in your better, more knoledged and more concise manner.

if you arent capable of doing so, then please dont talk as if you can.

Heretic, I think its a great post, but honestly I dont think your basics are "basic" enough for alot of members, lol

I'll be following the thread and maybe ask some quality questions when I can think more straightly

[AWDfreak]

Originally Posted by Camaro325

so why does the subaru wrx STI utilize the water spray into the intercooler when the computer feels the need for the intake to be cooled down....? is it bad then? thanks

The water I/C spray is manually controlled. (I think)

What Camaro325 asked, why does the STI have an I/C spray if it doesn't benefit it? Is it just a bad attempt at cooling down the I/C?.....

[Heretic]

Originally Posted by Camaro325

so why does the subaru wrx STI utilize the water spray into the intercooler when the computer feels the need for the intake to be cooled down....? is it bad then? thanks

The idea of water injection was first introduced in WW2 airplanes by Sir Harry Ricardo. Even with all the computer controls, the technology has not evolved in over 60 years. His book "The High Speed Internal Combustion Engine" is back in print. If you read this you will see just how much of this technology is recycled, and what was proven and disproven back then. Straight water into the intercooler has a minimal effect, but it does sell to those who do not fully understand what is happening

COOPER...I welcome criticism, but try being a little more specific. If you can disprove anything I have said PLEASE TRY.....I say again PLEASE TRY. I would like to insist that you are specific about it, and post something more than just your opinion. I want to see your explanation in your own words, not a repost from somewhere else. I could have done that myself, but I wanted others to understand, so I oversimplified. I would also like to see specific numbers to back up your opinions

I do admit an ulterior motive for wanting specifics from you. That way I can respond to your own information, and show everyone just who does NOT understand this topic
I think Car Buff was right about this...This may not be simplified enough for YOU to understand

[Camaro325]

Originally Posted by AWDfreak

The water I/C spray is manually controlled. (I think)

What Camaro325 asked, why does the STI have an I/C spray if it doesn't benefit it? Is it just a bad attempt at cooling down the I/C?.....

its both actually...i forgot...but one member on here who has a STI says it can be done manually or computer controlled...i think he said you should spray right before a race and never during hardcore acceleration...hopefully he can explain

[Heretic]

Originally Posted by Camaro325

its both actually...i forgot...but one member on here who has a STI says it can be done manually or computer controlled...i think he said you should spray right before a race and never during hardcore acceleration...hopefully he can explain

the idea of using for cooling before, and not during acceleration is because the water is NOT atomized. Since water does not compress, it raises the compression. too much water could raise the compression to dangerous levels

[Cooper "s"]

Well if you want my side of the explanation ill go for it, but no math because if you even knew how much math is involved in this it would take me too long to type it all.
First of all yes we all know what turbos and supercharges do, and their purpose. The reason why cars with turbos or supercharges run with inter coolers, is to cool down the induced air, thus slowing down the molecules and compressing even more (First law of thermo dynamics deltaU=Q-W). This way more oxygen can enter the chamber, and since combustion is fueled by oxygen, we get more energy form the explosion. Now the engine is running cooler, less energy is lost through heat, and it is more efficient. But before the technology was there to create inter coolers, airplane engines and car engines that ran at peak operations (racing or flying) by forced induction, were not reliable due to the immense pressure and heat generated by the increased volumetric flow of oxygen. Not only this but too much air makes the combustion to "lean", which means that there is a point when there is to much air and not enough fuel to produce a proper explosion and thus energy production reduces rather than increase. This is what Heretic meant by a 12.5:1 ratio is the maximum boost air fuel ratio before energy production reduces. So how to maintain the engine to run at its max and still produce its peak power? This is the idea of cooling the air by spraying water onto the air fuel mixture before entering the piston chamber. Not only does it cool the mixture (air fuel) and material surrounding (Engine) the mixture but as water heats up it evaporates, this gas expands producing greater pressure (because there is now more mass trying to expand in a confided space). This means that we now have more energy that in hand will produce torque as the piston moves.
Now that I have my basic explanation of the idea of injecting water in an engine, I want to comment that water is not corrosive to the engine only when mixed with ethanol due to its corrosive properties, just like it will corrode a gas tank if not made with materials to withstand this alcohol. Methanol is better to use and will not corrode the engine. Just for you all to know as a fact, the reason why alcohol is used as an additive is for a boost in octane. Also I have no idea what you are saying about spraying water in an inter cooler, what people do is spray over an inter cooler to cool the fins down, and have a greater heat exchange coefficient. Just like is in the WRX and Evolution.
This is as basic as I can explain, sorry i did not use math because there was no need, but I do want to comment something Heretic, next time you want to try and sound all fancy by copying off information you read on a site, try to understand what they are talking about before posting, and if you are to paraphrase other peoples work at least cite their work, because all of what you wrote was basically copy and paste. Here is the site Heretic used:
http://www.rbracing-rsr.com/waterinjection.html

[Car_buff]

cooper, I think you misunderstood what heretic was saying.

he's talking about "ricers" (you should know damn well how stupid they are) and how they are "wannabe turbo guru's", and how they spread the false truth that spraying water into the intercooler (basically improper use of water injection for high performance engines) cools down the air even further, thus produces more power out of a turbo application.

He was saying this is mostly false due to the properties of water. atomized it will stay, until it comes upon something, which in this case is the fins of the intercooler (on the inside). when atomized water comes into contact with anything like that, it condenses and goes from a semi gas (I'm not sure if the water is truly vaporised) to a liquid.

this may cool the intercooler down more, and may possible aid slightly in making the air cooler than with out it, however you know have liquid water being blown into your engine. atomized water can enter a piston and vaporise and aid in power, but liquid water being vaporised like that can create too much pressure on top of the pressure from normal activity and the forced induction of the turbo. Therefor it leads to engine failure.

He basically just saying thats the improper way of doing things. You better explained how it should actually be done, but again, I still think all of this is far above most members heads, however it may be fun for them to try and comprehend it.

btw, about the airplanes running lean, why didn't they just put bigger fuel pumps, or larger injector's on them? not too familiar with airplanes, and I dunno if they even had fuel injection that far back. wasn't at least popular in automobiles until I think about the 70's, and impeller propelled airplanes were basically long by then.

but they cant have had carburetors due to a carburetors needs to be nearly vertical to function, g forces and steep turns highly disrupt their functionality, and considering what I do know of the engine they had cylinder banks in a circle (rather than v config, or inline). mmm, it'd be interesting to learn more about those, how they work and what not

[monkeyfkker]

I'm staying out of this because I honestly don't know half as much about turbos as Lee and Cooper do. When we get into a discussion about blowers I'll be there. Anyway... if this turns into a massive flame thread I will close it.

[Car_buff]

everything other than how the air is forced is the same in either application.

surely ricer who use superchargers rather than turbochargers sometimes do the same mistaken water injection into the intercooler?

maybe not.

wonder if slowfiveoh has any say on the issue?

[monkeyfkker]

Ahhh but there are superchargers that force not only air into the engine... Those, to me, are blowers. So there! lol

There's a huge difference between a big ass turbo and a dual 4 barrel 14-71 B&M Blower on top of a 500 cubic inch Alcohol Rat motor.