THE BASICS

To start off, an explanation of a turbocharger is in order.



This is a Garrett Turbocharger. As you can see, it is made up of two sides. One side expels the exhaust gasses through a downpipe which leads to the exhaust, and the other takes in air through an intake and expels it through the chargepipes eventually ending at the intake manifold.

A turbocharger works by compressing the air flowing into the engine. The advantage of compressing the air is that it lets the engine squeeze more air into a cylinder, and more air means that more fuel can be added which in turn will lead to more power in each explosion.

For a Turbocharger to achieve this compressed air, the turbocharger uses the exhaust gasses from the engine to spin a turbine, which in turn spins an air pump. The turbine in the turbocharger spins at speeds of up to 150,000rpm. Because it is exhaust that is turning the turbine, the turbocharger gets extremely hot and needs to be cooled down by either oil, coolant or both.

here is another basic diagram of a turbo setup:



and here is a diagram of an actual turbocharger:





TERMINOLOGY

Now that you know how a turbocharger actually works, lets learn some of the terms that will be used in the rest of the writeup. some of these are the technical names, some are just abreviations used for ease of reading.

Turbo - Short for turbocharger, the main part of the system
Spool - The action of the turbo spinning the compressor to creat compressed air
Boost - The name for the compressed air the turbo makes
Intercooler - Like a radiator, but used to cool the charged air.
FMIC - A common type of intercooler, stands for Front Mount Intercooler
BOV - Short for Blow-off valve (this will be explained later)
Wastegate - A devise that bleeds off exhaust before the turbo so that it will not spool while idling.
Boost creep - When compressed air hits the throttle plate while idling
Idling - When the car is not moving but the engine is on
Dyno - A device used for measuring horsepower and torque numbers of a car
Tuning - The art of playing with a cars settings to make it run at the optimum ability
Chargepipes - The piping used to carry the compressed air to the engine
Dump tube - A single ppe that carries exhaust from the wastegate out of the engine bay
PSI - Pound Per square inch (mesurement of presure)


BASIC COMPONENTS OF A BASIC SETUP

So now you know your terms, lets build our first setup!

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Here is a list of every part in a basic setup and a description of what it does:

TURBOCHARGER - The actual device that compresses the air:



MANIFOLD - A special exhaust manifold, unlike the stock manifolds, these have a connection for the turbo and also for the wastegate, here are a few examples:





DOWNPIPE - The pipe that goes from the exhaust side of the turbo down through the engine bay and then connects to the catalytic converter and then out through the exhaust.

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INTERCOOLER - As mentioned earlier, an itercooler is like a radiator, but for air. air flows through it and then compressed air is pumped through the inside of it. They can come in many shapes sizes and forms, as well as placements. For example, on a stock Subaru STI, the ntercooler is placed under that giant hoodscoop, whereas on a Neon SRT-4, it is mounted in the front bumper.







WASTEGATE - A wastegate is a device that sits on top of the exaust manifold, before the turbo and when a certain presure is reached, the wastegate bleeds off exhaust gasses from the engine in order to stop the turbo from making more boost. It is very important to manage this because a turbo making too much boost will bow your engine in a second. A popular brand of Wastegate is Tial and Turbonetics. Noramlly they come with a spring rated for a certain PSI. This can be altered with a boost controller. Some turbos have a built in wastegate, although most peopel prefer to run an external wastegate so it can be adjusted easier.



BOV (blow-off Valve) - A BOV is a device that will releive presure from the chargepipes after the driver lets off the gas. This prevents boost from building up and either hitting the throttle plate or spinning the turbine in the wrong direction, which is BAD. BOV's come in many shapes sizes and forms. It is up to you which one you choose, although Greddy make some of the most well known styles.



CHARGEPIPES - The most simple part of the setup... the pipes that carry the compresed air from the compressor side of the turbo to the intake manifold. Although a simple concept, once making a high powered turbo setup, length of pipes, diameter, degree of bends all come into play. Aluminum is what most pipes are made from.



INJECTORS - In order to move more fuel into the engine, new fuel injectors are needed. on a simple syste, 450cc injectors are sufficient, although some high powered cars can run injectors upwars of 1200cc's.



ENGINE MANAGEMENT - Arguably the most important part of a turbo application is how the engine is managed. since there are so many ways and so many combinations of setups and devices, here is a list of the most common components, some standalone and some that need to be used together with other parts.

AEM Engine management System
Chipped ECU
MSD Boost timing mangaement
Apexi VAFC
Boost controller
Obd conversion
Map sensor missing link

As you can see, there are a few different ways to go. most likely, as i have found, the best way seems to be to go with a obd2 - obd1 conversion. To explain this, I will quote something i wrote in a recent thread:



"there is obd0 obd1 and obd2.

obd0 would be on i think any car before 1991, obd1 would be til around 95, and obd2 from then on.

obd reffers to the electrical system used in a car ie. the ecu and other ocmponents that control the cars functionality. the reason that you would have to convert a car to obd1 from obd2 to run a turbo setup is because the ecu's are far less complex and they are supported for chipping. now, the way you go about converting a car to obd1 or even obd0 (if your car was obd1) is by buying a new ecu and a new harness.

a harness is what plugs into the ecu from every single wire in the car that controls soemthing.



harnesses normally run about 70-100 dollars and come in many verieties. if you are a good electrician you can make your own fairly easy, but you need some good soldering skills.

the next part, and most important is the ECU. the ECU obviously is what controlls the cars functions. on our cars, the ecu is already preset to do things a certain way, but once you introduce the tunability of the ecu with something such as hondata, you are able to modify things. this is where you hear people mentioning taking off the speed limiter on the car. its all in the ECU.

if you are going to run a turbo or forced induction system on your car, one of the best things you can do is run a chipped ECU. for us accord owners, the ecu of choice is a P28 which i beleive is from a civic, although it could be from a teggy.

now once you have your ecu, it needs to be chipped, as you would with a games console, so you can modify setings. there are a few different types of tuning software you can use: chrome, hondata, uberdata (a copy of hondata), NepTune etc etc...

for my car, im using NepTune, a fairly new system for tuning. since i am not doing a transmition swap and i am looking to build a car for luxury and fun not for high speed, i will be keeping my stock auto tranny, until it dies when i will be getting a new one from Dr. Evil transmisions. anyway... neptune lets you tune he shift points, rpm limits, stall speeds and other vital settins on an automatic transmition, whereas most other tuning software will not.

anyway, once tuned to your needs, the ECU will have a map of the fuel/air ratios and other such settings. Of course with forced induction, the more air you push into the engine, the more fuel is needed. this is the job of a tuned ecu. although saying that, companies such as Apexi offer something called an AFC which manages the fuel injectors from a little computer in your car, mounted on your dash."


As I said before, this is what I think is the best and most complete way of running a turbo setup on our vehicles, but that can all be varied between each person with a turbo setup. Its all a matter of personal preference.

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GAUGES - Obviously, a guage monitors something. For a basic setup, a boost gauge is a must. There are many other gauge types out there, just look at what there is and see what you think you will need to monitor the most.



TUNING - Lastly, tuning is the final step in the turbo process. Although it is not an actual item, it is what will make your car run without issues and at the best performance possible. Normally, a tune would be done at a special shop with a dyno to mesure all the cars numbers and details. More can be found out on this by looking up your local tuning shop and calling or emailing them.




SHOULD I BUY A KIT OR GET THE PARTS INDIVIDUALLY?

This is a question that can only really be answered on your own. While i can suggest that you piece together your kit after A LOT of research, the natural thing would be to get a premade kit for your car and just bolt it on. Unfortunately as many people will tell you, it is not that simple. As well as that, kits are noramlly made with substandard parts and are overpriced. a good kit can be pieced together for our cars for about $3000. a kit may cost a few hundred less then that, but you do not get half the quality parts you would if you did it yourself.

a few examples of companies that make kits for our cars are:

FMAX
Turbonetics
Drag

There are however, other manufacturers that make kits. one being the natorious SSAUTOCHROME. if you ever see that name on anything you are looking at buying, go wash your ees out with soap.

if you are wondering why i warn you so much about not ever ever ever buying something made by them, let these photos do the talking...





yes, that turbo is completely cracked in half. feel safe putting that in your car?? thought not.

As I have mentioned, there are more components that are part of turbo setups, all of which benefit or aid in the production of pwer and the management of the engine, but there are too many to list. I will continue to update more to this thread as it is a "work in progress" but hopefully this will let you in on some of the basics of turbochargers.

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In your oppinion what is a fairly inexspensive BOV that will work well with my stock parts for now?

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well they are all fairly expensive, so if $200 is expensive then your kind of stuck. what do you mean by stock parts? what kind of car do you have?

also, take into account that a cheaper BOV will be made cheaper. Id reccomend greddy or HKS, since they are the most popular. there is also turbosmart and xs probably make BOv's too as well as turbonetics and blitz. when your looking at a BOV i think once you decide to spend 200, its more about sound then anything else

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I think 200 is inexspensive. I have the wrx in the pic. What i mean by stock parts is that the turbo and intercooler are stock no upgrades there as of yet. And what size and style BOV should i consider, basicaly what im askin is whats goin to work best for a daily driver that gets the shit beat out of it at any given time someone try's me.

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lol didnt see the pic when you made the post. umm for your car, id look at the HKS SSQV. i dont know that much about scoobies but as long as you have the right flange, it will fit.

what id recomend is a front mounbt intercooler. that will give you some power and you can add the BOV at the time. i know with the STI you make about 50hp with some of the FMIC kits, so idk about the WRX. its worth it though.

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I'll add some of the knowledge I have from owning a turbo'd saturn for about a year.

The most important part of any turbo build is tuning.

Power is made how much air you can flow thru the system NOT the PSI of the system

TUNING TOOLS NEEDED

Any type of standalone listed above, Don't use RRFPR they are a band aid and when your piece together a turbo kit a GOOD fuel solution is the LAST thing you want to save money on.

LAPTOPUnless your going to take your car to a dyno every few weeks your going to need a laptop to tune with

just tuning WOT runs on a dyno will not get you the best tune and it is ALWAYS better to street tune the car before dyno runs as it will save you time on the dyno and that equal saved money

GAUGES

at a minium I would suggest boost/vaccum , EGT , fuel pressure, oil pressure, and MOST IMPORANT Wideband O2

the reason for the EGT is you can get a lot better tune and more power then just tuning off just a wideband

Boost is obiviously to make sure you not over boosting and to make sure your boosting at the level your want to be (A good idea if you don't mind is getting 2 boost gauges put the boost/vaccum gauge off the Intake manifold and place a regular boost gauge off the nipple on the turbo)

Using 2 boost gauges will allow you to monitor pressure drop across your system which is usually 2-3 PSI from the intercooler IF it it around 5 or MORE PSI you have a boost leak its time to looking at your charge pipes and couplers

Fuel pressure is more so if you decide to be cheep and use a RRFPR but also its more of a good thing to keep tabs on, if you dont have fuel pressure pull your ass over immedately

Same goes for oil pressure

now the big one

The wideband is a valuble tool to anyone with a turbo set up

this small device can save your engine

Narrowband tuning is completely useless... it will only tell you if your engine is about to blow up or if you running too much fuel, a wideband will give you the excat (to the nearest 0.1) ratio of air to fuel from your exhuast gasses.

You want to place the sensor 36-48 Inches from the turbo turbine in the downpipe

some of the good gauges to look at are AEM and PL-X.

with this gauge you will be able to at least street tune your car before a dyno run, as well as you'll be able diagnous problems a little eaiser, also it's always a giant piece of mind to see that 12.0-12.5 reading when you flying down the 405I at 95 boosting 9PSI at 3:30 in the morning =)

A few things about intercooler sizing

The Biggest intercooler is not always better

sure it looks awesome to have a ginamous front mount in your grill but if you have a tiny ass turbo and a huge intercooler you will be losing some power from that intercooler.

When I use to help an import shop we had a customer with a mazdaspeed miata, the first mod he wanted was an evo 8 intercooler he got from a friend to be used in his car.

After trying to explain how it would hurt his performance he wanted it anyway, so we welded it all up and got it installed in his car, now the normal pressure loss on these car stock is 2.5 PSI thru the system thats pretty good.

The customer returns 3 days later complaining that we screwed up his car.. hes boosting less and its slower

well I hooked up a boost gauge to his compressor housing... there was now a 5 PSI pressure drop... told ya so came to mind.

so remember bigger isn't always better I'll search around for my notes on how to size intercoolers but I think www.turbobygarrett.com has a write up on it.

Turbo sizing

If you making a custom kit learn to read or find someone that can red compressor maps.

Smaller turbos = quick spool but may run out of breath at the top end

Larger turbos = longer spool(aka boost lag) but will have power to redline(and probably past)

this is where hybrid turbos come in (ie T3/T4) these turbos have the best of both worlds a small exhuast turbine but a large compressor turbine

the helps wil spool up as well as being able to flow the air needed for higher boost levels and HP levels

if your a baller a ball bearing turbo will all but elimate boost lag and have the ability to flow lots of air.

Sizing injectors

When you going to get injectors you need to check a few things

what PSI the injectors are rated at
will they physically fit your fuel rail
are the satureed or peak and hold injectors
how much HP are you looking at

if an injector is rated 800cc at 100PSI flow rate that means you need your fuel system to be at 100 PSI to flow that much, make sure when you order injector to make sure they are rated at when you cars fuel system will be at (I believe standard is 43.7)

when planing a turbo build you need to have a HP goal, it has to be realistic... a T25 turbo at 6 PSi isn't going to be a 300whp car sorry not going to happen, also make sure you have big enough injector to handle MORE fuel then you will need... you can always take away fuel... but if your running the injectors at 100% duty cycle you going to lock them open.... Never run injectors above 80% duty cycle for safety reasons

and my Last point:

never plan your system to ONLY handle 5 PSI

something will happen.

you'll get the boost bug
you'll overboost
A ghost will turn up your boost controller without you know

something will happen it's always better to design your system for more boost then you plan on running, If you have a system thats barely holding together at 5 PSI and you overboost for whatever reason bye bye motor, besides one of the BEST parts of owning a turbo system with an electronic boost controller is that moment you reach down, raise that boost for that straight away and instally gain 20whp by raising the boost

Overall power comes with responsability if you don't think you can handle a boost controller don't get one till your system can handle it the power to raise you boost from your driver seat is a LOT of power, if you cant keep your hands off the boost knob don't have it there

any turbo system can bve reliabilty if it planned out correctly and the driver is responsable with it

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2000 Base prelude
AEM CAI
Pspec Shortshifter
more mods coming...

I have talked to a couple people who say a front mount intercooler would more than likely slow my car down do to the size of the turbocharger. I havent done any research on this as of yet but thank you all for your good info.

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yes a front mount and a stock WRX or STI turbo will infact slow the car down due to the pressure drop from the added pipping and the increased size of the turbo... you need to turn your boost up around 2.5PSI to get back to your stock level in your Intake manifold after doing so.

The trade off though is when you DO get a bigger turbo it will cool the air better/more and it looks cooler =P

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2000 Base prelude
AEM CAI
Pspec Shortshifter
more mods coming...

in your situation, the turbo probably would spool slower with an FMIC but i think if you did some work, you could benefit from a new turbo and a fmic

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the turbo actually spools at the same speed its just you have a drop loss thru the new piping and thru the larger Front mount. So it auctually has to work harder to get the same about of compressed air to your intake manifold. BUt the air is cooler and a lot denser you also might run a tad leaner becuase more air will be flowing thru.

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2000 Base prelude
AEM CAI
Pspec Shortshifter
more mods coming...

I did find a TD05 charger and large top mount intercooler with all hardware for $500. on ebay. Was told it only had 25k on it and was guaranteed, im always sceptical of things that are to good to be true

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mustangeater, from what i have read about scoobies, you do not need a bov. until your car is pushing past 20psi then you can consider getting one, but the bypass valve already on the car is good enough, because if you get a bov, it might run too rich. i could be wrong on this but check out nasioc.com, they know their stuff. thats where i read about that. if anything, upgrade your tmic, i think that will be quite good for the time being

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your BOV is good for like 22 PSI

IF you do upgrade your BOV you HAVE to get a recirulating one, your stock computer is programed for that air to be recirulated and it adds fuel for that... if you have your BOV dump to the atomsphere you will run richs between shifts and lose some power so unless you are getting a fuel computer or ECU that is programed to dump to the atomsphere you HAVe recirulate your blow off.

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2000 Base prelude
AEM CAI
Pspec Shortshifter
more mods coming...

Thanx for the info.

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i have an sr20 with fmic and atmospheric bov. my turbo is boosting stock 7 psi. will my safc fix that when tuned? i think i'm running rich between shifts. if i buy a recirculation kit will i still here the bov? thanks.
-marques

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yes a SAFC2 can fix the problem
yes you can still hear the BOV with recutulation but it's not nearly as loud as without, if you want to here Blow off and have a SAFC2 just tune with it your dyno tuner should know how to tune for that.

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2000 Base prelude
AEM CAI
Pspec Shortshifter
more mods coming...

oh really. i have the safc 1 (the one with the buttons and it's blue) will that work?

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