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Home > Performance Mods > Engine Mods > Beginners Introduction: Turbo

Beginners Introduction: Turbo

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Orin Auburn Alabama, US	The numerous threads about turbo have inspired me to write this post about turbo. I am not an expert on turbo, but I will certainly be glad to share what I do know. Future posts will have more information. Let's not let this post become a competition over who knows the most, I will delete your posts, do not ask why your post was deleted, you should have read it here first. do not post questions asking which kit will give you the most hp, it will be deleted. Open a new thread and keep post on topic any discussion of which brand to buy will be deleted, open a new thread This post is not an end all guide, but should help people who are starting to learn about turbo. That all being said, let's talk about TURBO What is turbo? A turbocharger is essentially a compressor which is powered by exhaust gases being fed into turbine fins in very much the same way steam drives the turbines of a nuclear power generator. The hot gases escaping from your car's exhaust manifold moves toward the turbo's turbines and spins them at speeds of about 150,000 rpm Another set of turbine fins being spun by those exhaust fumes is taking in air and compressing it. A tremendous amount of air that also gets very hot during compression. This compressed air gets jam-packed into your vehicle's combustion chamber. Vicious: "wait, you lost me there... what?" Right now in a naturally aspirated vehicle (N/A or non forced induction) your intake is taking in air. Turbochargers take in a lot MORE air and squeeze it real tight then force feed it to your engine like Rosie O'Donnell at the chowing down at the buffet table. The result is more power if your car can handle all the compressed air or boost. What makes boost so risky for most engines if the block or moving parts inside your car can't handle all the extra pressure or compression All internal combustion engines use compression as part of the combustion process, but turbochargers are upping the whole process by at least 50% more. The incoming air allows even more fuel to be burned provided the conditions for ignition and timing are correct. *Vicious: "what do you mean by conditions being correct?"* One of the most crucial parts of turbo charging involves getting the correct air/fuel mixture and ignition timing. That's one of the reasons why turbocharged or forced induction vehicles use a much higher octane of fuel. If it's out of whack, you get something called detonation. If detonation occurs, everything melts and you can kiss your sweet engine goodbye. Higher octane fuel also prevents knock and we'll talk about that later. ^click the image for a large cutout showing the inside of a turbocharger Intercooler The main purpose of an intercooler is to cool the air after it's been boosted and heated by the turbo. Cooler air is denser and will burn a lot better in your combustion chamber than hot air. The cooler air will also reduce the chance of engine knock. The intercooler will also help your turbo reach higher horsepower numbers. Most intercoolers will be an air to air design which simply allows air to pass through it. There are other designs, but for low cost and low maintenance, the air to air intercoolers will be the right choice for most street driving. Wastegate A wastegate is simply a bypass valve that allows excess gases to bypass the turbines to keep them from spinning too fast. This is another way of reducing your boost. *Vicious: "..but wouldn't a faster spinning turbo mean more power for me?"* The normal amount of air pressure or compression being fed into your combustion chamber is good. It's measured is pounds per square inch or PSI, but if your turbine spins too fast that also means you're creating too much boost. You can have too much of a good thing and the result is stress on your engine's internals and possibly damaging the turbo itself. PSI or boost is something that should always be controlled. image of a typical external wastegate, an external wastegate is self contained and completely separate from the turbocharger. Turbo Lag *Vicious: "What is is turbo lag?"* Turbo lag refers to a delay in boost when the throttle is open. There is a lot of things that cause lag and there are lots of ways to reduce it. *Vicious: "How do I reduce turbo lag?"* Ah, that's the fun part, you can reduce back-pressure by getting a larger diameter exhaust that allows more turbo gases to escape. Turbo's need more gases to escape, a lot more than a N/A car. So most tuners get a 3 inch diameter exhaust connected to the back of the turbo. You can also reduce the inertia of the moving parts by getting a lighter flywheel or using a smaller turbo. Even helping the intake side of things can reduce lag. BOV -- Blow Off Valve It's more than just that lovely sound you get "whooooshhhh" Believe it or not, the BOV has a very serious purpose. The purpose of the blow off valve is to prevent compressor surge. *Vicious: "..what is compressor surge...?"* I knew you were going to ask that.. Compressor surge happens when the charged or boosted air is more than the compressor itself can handle. This condition can cause the compressor wheel to back up, build pressure and stall. If a turbocharger stays in compressor surge for long, the turbocharger can become damaged. The blow off valve works to release this excess pressure into the atmosphere so the turbocharger does not go into compressor surge Orin: I hope you've found this introduction on turbo to be helpful, as mentioned above, it's not an end all but more of a beginner guide to some things about turbo. I'm hopeful other users will create their own posts that can help new aspiring turbo fans learn more about how to do it right. thanks to: Vicious --- for letting me use him as the question guy. dsm3383 and java09 are willing to answer questions. keep this post ON TOPIC related links: Beginners Introduction to Turbo Part II Howstuffworks.com: How Turbochargers Work Installing A Turbo Kit, What Else Do I Need? Engine: The Internal Combustion Process Why Air Gets Hot last updated by Orin on 02/09/08 --- 07:11 central
[#] Feb 08, 2008 02:15pm
scionteecee Fairfax Virginia, US Chief Mechanic	great thread!
[#] Feb 08, 2008 02:16pm
bboydoc East Rutherford New Jersey, US Tech Advisor	sweet can't wait til i get my turbo
[#] Feb 08, 2008 02:41pm
java09 Honolulu Hawaii, US Godlike Advisor	Nice post Orin! very good stuff, you used KISS. Keep It Simple Stupid! best way to do anything! EDIT: "So most tuners get a 3 inch diameter exhaust connected to the back of the turbo." although true in a lot of applications for the sake of those turbocharging their "tC" 2.5 inch exhaust from the turbine/s-pipe back is more than enough. it keeps exhaust temps hot enough to help them scavenge, which allows for faster turbo spoolup, and more horsepower. toooo big (3inch) for the tC exhaust pipes will cool the exhaust gases down. This creates turbulence and back pressure. The result is actually a loss of power. When you make enough boost, power, and heat, then you can consider 3 inch. 2008 Turbo Scion tCizzle POWERED BY TURBOTOYOTAS! 310WHP, 272WTQ more to come_..
[#] Feb 08, 2008 03:15pm
Orin Auburn Alabama, US	Thanks mang, I know you'll help out with answering questions that come up too, it's appreciated.
[#] Feb 08, 2008 03:36pm
java09 Honolulu Hawaii, US Godlike Advisor	no prob! your info was great ill just kinda pin point a little more for the "tC" in general as im sure others will! 2008 Turbo Scion tCizzle POWERED BY TURBOTOYOTAS! 310WHP, 272WTQ more to come_..
[#] Feb 08, 2008 03:37pm
cessblood Boston Massachusetts, US Master Mechanic	Nice I don't pimp my ride. I'm a pimp in my ride. http://www.myspace.com/cessblood http://www.facebook.com/profile.php?id=708110639 http://www.itsmyscion.com/cessblood CesswillStompdashitoutu
[#] Feb 08, 2008 04:52pm
RoulettetC Frederick Maryland, US Scion Guru	That cleared up a lot, thanks bud. -Thanks for the sig Aciidsneaker
[#] Feb 08, 2008 05:02pm
krdshrk New Brunswick New Jersey, US Godlike Advisor	Very well put together. I'm no beginner though Scikotics NJ is sponsored by Lawrence Scion 2006 GReddy Turbocharged Automatic tC 220+ WHP - 14.044 @ 97.02 MPH
[#] Feb 08, 2008 05:05pm
Orin Auburn Alabama, US	Most experienced turbo tuners would find this information very elementary, but I don't want to overwhelm with TMI too much information. So I wrote things in my own way rather than copying and pasting. This won't be the last turbo post, eventually I'll create more posts to complete a bigger picture. More to come
[#] Feb 08, 2008 05:21pm
dsm3383 Rochester New York, US Scion Guru	java09 wrote: Nice post Orin! very good stuff, you used KISS. Keep It Simple Stupid! best way to do anything! EDIT: "So most tuners get a 3 inch diameter exhaust connected to the back of the turbo." although true in a lot of applications for the sake of those turbocharging their "tC" 2.5 inch exhaust from the turbine/s-pipe back is more than enough. it keeps exhaust temps hot enough to help them scavenge, which allows for faster turbo spoolup, and more horsepower. toooo big (3inch) for the tC exhaust pipes will cool the exhaust gases down. This creates turbulence and back pressure. The result is actually a loss of power. When you make enough boost, power, and heat, then you can consider 3 inch. Java, how does exhaust temperature have anything to do with the spooling of a turbo? A centrifugal turbocharger works as an "air" pump that spins the turbine from the air pressure that builds up in the manifold. (I am not bashing what you said but would like an clarifying response.....SO Orin I am not being a dick haha ) From all I know on internal combustion engines and the thermodynamics of heat engines. Heat as a byproduct is always undesired. Heat is energy and losing heat as a byproduct means less power that is actaully generated by the engine itself. So, my personal opinion is to cut the heat that is a byproduct from your engine. I have always recommended a 3 inch exhaust cause you want it wide open with no restrictions on a turbocharged engine. Also, with extra heat means your intercooler will not cool the air down as much that in the end decreases your volumetric capacity (density) of air into the combustion chamber thus in all reality being less boost. That is my input and yes it is open for discussion and feedback. I will be looking forward to your response Java since I am interested in your insight. By the way, cool thread Orin. It makes it alot easier for newbies to read up and learn from one "stickied" thread then a couple of us boostheads repetively answereing the same questions (even though I never get bored of talking about turbos!). Beer is proof that God loves us and wants us to be happy. -Ben Franklin
[#] Feb 08, 2008 06:35pm
dsm3383 Rochester New York, US Scion Guru	Orin wrote: *Vicious: "How do I reduce turbo lag?"* Ah, that's the fun part, you can reduce back-pressure by getting a larger diameter exhaust that allows more turbo gases to escape. Turbo's need more gases to escape, a lot more than a N/A car. So most tuners get a 3 inch diameter exhaust connected to the back of the turbo. You can also reduce turbo lag by your intercooler set-up. Most turbo lag is created from the time the boosted air comes from the turbocharger itself and travels through the intercooler and then dumps into the intake manifold. Subura WRX STI have almost no turbo lag. Why? They have a top mount intercooler and the distance between the turbo and intake manifold is very minimal. I would love to see a top mount intercooler set-up on a tC. Also, intake and charge piping sizing between the intercooler is critical and if designed correctly can minimize the lag. And the correct choice of a intercooler with minimum pressure drop to obtain desired air outlet temperature with regards to size. Beer is proof that God loves us and wants us to be happy. -Ben Franklin
[#] Feb 08, 2008 07:05pm
dsm3383 Rochester New York, US Scion Guru	Orin wrote: Intercooler The main purpose of an intercooler is to cool the air after it's been boosted and heated by the turbo. Cooler air is denser and will burn a lot better in your combustion chamber than hot air. The cooler air will also reduce the chance of engine knock. The intercooler will also help your turbo reach higher horsepower numbers. Most intercoolers will be an air to air design which simply allows air to pass through it. There are other designs, but for low cost and low maintenance, the air to air intercoolers will be the right choice for most street driving. The purpose of cooling the air is to make it more dense which results in the air taking up less space (volumetric capacity). What this does is allow so much more air molecules inside the combustion chamber. With that you can increase how much fuel is dumped in also which when combined with a spark goes BOOM! MORE POWER IS CREATED!!! Beer is proof that God loves us and wants us to be happy. -Ben Franklin
[#] Feb 08, 2008 07:12pm
java09 Honolulu Hawaii, US Godlike Advisor	dsm3383 wrote: java09 wrote: Nice post Orin! very good stuff, you used KISS. Keep It Simple Stupid! best way to do anything! EDIT: "So most tuners get a 3 inch diameter exhaust connected to the back of the turbo." although true in a lot of applications for the sake of those turbocharging their "tC" 2.5 inch exhaust from the turbine/s-pipe back is more than enough. it keeps exhaust temps hot enough to help them scavenge, which allows for faster turbo spoolup, and more horsepower. toooo big (3inch) for the tC exhaust pipes will cool the exhaust gases down. This creates turbulence and back pressure. The result is actually a loss of power. When you make enough boost, power, and heat, then you can consider 3 inch. Java, how does exhaust temperature have anything to do with the spooling of a turbo? A centrifugal turbocharger works as an "air" pump that spins the turbine from the air pressure that builds up in the manifold. (I am not bashing what you said but would like an clarifying response.....SO Orin I am not being a dick haha ) From all I know on internal combustion engines and the thermodynamics of heat engines. Heat as a byproduct is always undesired. Heat is energy and losing heat as a byproduct means less power that is actaully generated by the engine itself. So, my personal opinion is to cut the heat that is a byproduct from your engine. I have always recommended a 3 inch exhaust cause you want it wide open with no restrictions on a turbocharged engine. Also, with extra heat means your intercooler will not cool the air down as much that in the end decreases your volumetric capacity (density) of air into the combustion chamber thus in all reality being less boost. That is my input and yes it is open for discussion and feedback. I will be looking forward to your response Java since I am interested in your insight. By the way, cool thread Orin. It makes it alot easier for newbies to read up and learn from one "stickied" thread then a couple of us boostheads repetively answereing the same questions (even though I never get bored of talking about turbos!). turbines spin using exhaust heat energy, not really exactly just like an "air pump" the more heat energy you lose through a 3 inch exhaust on a mildly turbocharged car, i.e. stock internals on the tC with a TurboToyotas Stage 1 kit slapped on it (my car as an example) the more power you lose. on the flip side a built motor running higher boost would actually that 3 inches of flow to reduce the exhaust gas temps. simply put when the temps cool to much your exhaust gases cool too much and you get back pressure which in turn causes you to lose power and have a slower spool. thats what ive always thought to be true. in your case i see what you are saying but i strongly feel that mildly powered tCs with a bolt on turbo kit really only need 2.5 mandrel bent piping all the way back! i think there is a big diff when you are talking about a built motor and higher boost settings. then you have to worry about cylinder pressure and the heat created by that as well. 2008 Turbo Scion tCizzle POWERED BY TURBOTOYOTAS! 310WHP, 272WTQ more to come_..
[#] Feb 08, 2008 08:11pm
java09 Honolulu Hawaii, US Godlike Advisor	also haha my name is brandon btw. ehh listen to the clip on this, does it sounds like compressor surge to you? im not to fluent with TT systems but i dont think that would affect the sounds at the end of the rev. thoughts? http://www.clubsciontc.co...andra-aka-the-beast-.html 2008 Turbo Scion tCizzle POWERED BY TURBOTOYOTAS! 310WHP, 272WTQ more to come_..
[#] Feb 08, 2008 08:41pm
dsm3383 Rochester New York, US Scion Guru	java09 wrote: turbines spin using exhaust heat energy, not really exactly just like an "air pump" the more heat energy you lose through a 3 inch exhaust on a mildly turbocharged car, i.e. stock internals on the tC with a TurboToyotas Stage 1 kit slapped on it (my car as an example) the more power you lose. on the flip side a built motor running higher boost would actually that 3 inches of flow to reduce the exhaust gas temps. simply put when the temps cool to much your exhaust gases cool too much and you get back pressure which in turn causes you to lose power and have a slower spool. thats what ive always thought to be true. in your case i see what you are saying but i strongly feel that mildly powered tCs with a bolt on turbo kit really only need 2.5 mandrel bent piping all the way back! i think there is a big diff when you are talking about a built motor and higher boost settings. then you have to worry about cylinder pressure and the heat created by that as well. Java (a.k.a. Brandon), I am sorry but I do have to correct you. A turbocharger does not work off of exhaust heat energy. "A turbine is a rotary engine that extracts energy from a fluid flow" You are mistaking a "gas turbine" with a turbocharger. Yes, the turbine itself in a turbocharger is also referred to as a "gas turbine" and is for the reason that it operates off of a hot gas (exhaust). But the fundamentals of a turbocharger and how it works is completely different from a "gas turbine". See Gas Turbine for a full description. The exhaust system is after the turbo. Having a larger port to expel the "unused" gas will provide less turbulence and backpressure seen in the turbocharging system of the engine. I think what you are trying to get at is manifold design. A manifold that is too large takes extra time to build up the pressure needed to open the wastegate to let it spool and feed your turbo. I agree, the Turbo Toyotas manifold is really nice looking but is more for looks. It is quite large and has alot of internal volume. This causes more time for the pressure to be created in it. The cast manifolds (e.g. Treadstone) are very small in size in comparison. It may not be equal lengths but the pressure can be built up relatively fast due to the decrease in volume. It may be true that because of your manifold design increasing the backpressure from your exhaust may actually help spool the turbo faster but it is inproper and placing more stress on the turbochargers internal components. You want to expel whatever gases are not used out of the system as easy as possible (no exhaust would be the best haha ). Beer is proof that God loves us and wants us to be happy. -Ben Franklin
[#] Feb 08, 2008 08:46pm
java09 Honolulu Hawaii, US Godlike Advisor	equal length>log manifold everyday and any day will out preform. todds manifolds arent the best on the market because they look nice, they are the best performance wise too. which is why dezod is also making a race manifold "equal length" and i stand corrected above your right i was in left field.. i was correct on another subject! haha 2008 Turbo Scion tCizzle POWERED BY TURBOTOYOTAS! 310WHP, 272WTQ more to come_..
[#] Feb 08, 2008 08:53pm
dsm3383 Rochester New York, US Scion Guru	java09 wrote: equal length>log manifold everyday and day will out preform. todds manifolds arent the best on the market because they look nice, they are the best performance wise too. which is why dezod is also making a race manifold "equal length" and i stand corrected above your right i was in left field.. i was correct on another subject! haha True, a log manifold has its downs cause it creates alot of turbulence but the pressure it builds is much faster. The problem with those manifolds is keeping the same amount of pressure within the chamber to feed to the turbo. So through your entire rpm range you might be going e.g. 8psi to 7psi back to 8psi then to 6psi. For a street driver I would recommend a log manifold. Equal lengths do not exhibit this (they are consistenly placing out the same amount of pressure all the time). Yes, they are better for racing applications. If you are racing then you have a built motor most likely. With a built motor your rpm range is much higher cause of the internal work done (head work). In this scenario turbo lag is really no issue. Beer is proof that God loves us and wants us to be happy. -Ben Franklin
[#] Feb 08, 2008 08:57pm
java09 Honolulu Hawaii, US Godlike Advisor	on a properly set up equal manifold too.. i have seen some that completely make the equal length design useless. the runners must be chambered correctly and have good welds/bends. id say todd as done an excellent job with his manifolds! 2008 Turbo Scion tCizzle POWERED BY TURBOTOYOTAS! 310WHP, 272WTQ more to come_..
[#] Feb 08, 2008 09:01pm
dsm3383 Rochester New York, US Scion Guru	java09 wrote: on a properly set up equal manifold too.. i have seen some that completely make the equal length design useless. the runners must be chambered correctly and have good welds/bends. id say todd as done an excellent job with his manifolds! Oh, of course. The design of turbo manifolds is VERY IMPORTANT! I too have seen some manifolds that just were sh*t from the get go because somebody knew how to weld. Don't get me wrong I like the Turbo Toyotas manifolds. I am just starting to get into real specifics with applications. I rather would have a equal length manifold anyday over a log manifold. But if your just buying a kit for street driving (no internal modifications) and only going to put down 8psi max then the log manifold will do you just fine. Now if you want to build and race at the track.....equal lengths is the only way to go. Beer is proof that God loves us and wants us to be happy. -Ben Franklin
[#] Feb 08, 2008 09:06pm
Kurisutaira Godlike Advisor	ok i have a question about maintenace. i read on trd, was either the t/c or the s/c cant remember. but about letting the fluids cool before shutting down? how long till u reach your break in period with a turbo? and dureing the start up, how long wuld u need to let it warm up in comparison to a regular ignition? also with the intercooler i assume u can have a hydro based? and if this is true is there any performance difference? * i have an auto and also wondering wuld it really even be worth the investment? not sure if there is something the manual has over the auto that wuld render the feature for a turbo as something for asthetic purposes "This is what happens when an unstoppable force meets an unmovable object"
[#] Feb 08, 2008 09:32pm
dsm3383 Rochester New York, US Scion Guru	Kurisutaira wrote: ok i have a question about maintenace. i read on trd, was either the t/c or the s/c cant remember. but about letting the fluids cool before shutting down? how long till u reach your break in period with a turbo? and dureing the start up, how long wuld u need to let it warm up in comparison to a regular ignition? also with the intercooler i assume u can have a hydro based? and if this is true is there any performance difference? * i have an auto and also wondering wuld it really even be worth the investment? not sure if there is something the manual has over the auto that wuld render the feature for a turbo as something for asthetic purposes Yes, the turbo/supercharger need to cool down. Usually just 30 seconds in idle is fine. Just send a text message, fix your hair, etc.., and your good haha . Break in depends on manufacturer in my opinion. Talk to the manufacturer and get their recommendation. Yes, their are air/water intercoolers. Remember a intercooler is a heat exchanger so all those principles apply. They are rare and very hard to maintain and install. An Auto? Well if you just want a basic kit and a little more pep it is ok. If you want to put down numbers then its not worth the money. It really is up to your own personal decision. Beer is proof that God loves us and wants us to be happy. -Ben Franklin
[#] Feb 08, 2008 09:40pm
Orin Auburn Alabama, US	keep brand discussion out of this thread see my original post
[#] Feb 08, 2008 09:57pm
Orin Auburn Alabama, US	Orin wrote: do not post questions asking which kit will give you the most hp, it will be deleted. Open a new thread and keep post on topic
[#] Feb 08, 2008 09:57pm
Orin Auburn Alabama, US	feel free to discuss, but if you plan on writing a guide create a new thread. instead of constantly updating this thread with more information, future threads will be created. I also encourage others to create their own original material.
[#] Feb 09, 2008 08:11am

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