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03OrangeSVT 01-08-2008 09:39 PM

So you're planning on going FI
So you've decided to go turbo.... NOW WHAT???

You need to decide on what you power goals are then you can start planning from there. You need to start with the most basic of decisions... stock motor or built?


The biggest advantage of using a stock motor is COST, but going the cheap route is going to limit the amount of power you can make.

On a NON-SVT engine (Zetec and Duratec) you can run around 12psi before you start getting into the "breaking" zone.... as in where you start breaking rods.The Zetec and Duratecs both use powdered rods and they are THE weak link in your motor.

SVT's... You guys are the lucky one's when it comes to boost. SVT had the foresight to use sinter forged MAHLE rods in your motors which give you a BIG advantage when it comes to boost. The weak link in the SVT motor is its pistons. You can easily run 17psi on an SVT motor... personally I ran 19psi for 2 years before getting power hungry and .... well needing a new engine.


For the serious driver a built engine is a must.. but there are several different levels of building.


The cheapest and most popular is to just swap out the stock rods and pistons for forged aftermarket ones. BOTH Zetec/SVT/and Duratec have to swap out rods and pistons when upgrading.... yes even though the SVT has forged rods they too have to be swapped since no one makes an aftermarket piston that works with the SVT rod.


The standard SVT/Zetec block should be good to somewhere over 20psi, there have been many people do this on the stock stuff. The only difference between the Zetec and the SVT blocks are oil squirters (SVT) that blow oil onto the bottoms of the pistons to help cool and lubricate them... are they needed... not really but they are nice to have.

If you have an extra $1500 laying around and if you can find one Montune makes a CGI Zetec block which are rated for 32psi of boost. CGI means carbon graphite impregnated... the same stuff the PowerStroke blocks are made of... An EXCELLENT choice for big boost.


Well the SVT guys came out ahead here too, the STOCK SVT head/cams are excellent for boost.. and its a good thing since there really is NO aftermarket support in this area in the United States. You can get a good Port & Polish and bigger valves but no one makes a direct swap without going out of country.

Zetec's.. you guys have several choices on cams (which I'm not going into) and you guys get the FordRacing head that already comes ported with bigger intake valves in it. Of course you can still get a P&P and do valve work to it as well... but its pretty damn good out of the box.

When choosing cams you should look for "boost specific" cams, there is a difference. When building a motor for FI your cams should not have alot of overlap. when you get too much overlap you basically end up blowing your boost out of the exhaust. On the bright side you can install cam gears and dial out some of the overlap if you already have "larger NA cams"


There are not many choices out there, the SVT guys are pretty screwed. Unless you make an intake, you are stuck with the DSI. I say stuck for the basic reason of the DSI flows like crap... thats why i dont have one.

Zetec's have a couple of choices, an early 2000 intake, the FordRacing intake, or make one. Even though the STOCK manifold isnt bad.

Now before you run out and start hacking on pipe trying to make a manifold you seriously need to go read about flow dyanamics, design, runner length, plemium volume and get an understanding of what needs to be designed into the intake... just throwing one together can greatly decrease you power... no matter how COOL it looks.


No one makes one... why you just dont need it. Tom is the only one I know of that has broken a crank... at 720whp.


A lightend flywheel is a GREAT addition to any Forced Induction motor, they let the engine rev extremely quick (compareed to stock) the only downside I see from a light weight flywheel is they tend to rattle a little, but its worth it.

I also recommend an upgraded clutch, if you dont do it now.. you WILL do it later. Theres just no way around it. A stock SVT clutch will let go around 250wtq and the MTX 75 is less than that. I suggest at least a stage 3 clutch for the MINIMUM clutch to use.


I'll be upfront, you guys are definitly limited by your transmissions. BUT there is still hope!!! Lentech makes a wide variety of stuff for the Focus ATX and if you want more than 220whp or so then you need to go to their website and look around.


The single best thing you can do (and pretty much the only thing needed) is install a LSD.. Limited Slip Differential. An LSD it what lets you get the power to the ground, without it you're just going to spin one wheel... and thats some embarrising shit. The LSD will also help you with daily driving .. they are great for handling in curves and greatly help in the rain.

The 2 REAL choices are Quaife and Torson.... what about OBX did you say??? Not even in my lawn mower... I wont even discuss that... go find a Honda forum.



Regaurdless of your power goal 42# injectors are the minimum that I would even consider using... they are just a few bucks more than smaller ones and can save your motor.

ALWAYS use a properly sized injector... too big is fine, too small is dangerous.


I would not recommend anything less than the '03 upgraded fuel pump, the older pumps just dont flow as well.

Using a stock fuel pump and fuel rail you can manage around 250whp safely on both Zetec and SVT. With a BOOST A PUMP you can get quite a bit more out of the Zetec closer to 300whp... providing proper tuning.

On the SVT with a BAP and proper tuning (that I figured out) you can achieve well over 350whp on the STOCK fuel system. I have datalogs showing 62psi of fuel pressure at 7200rpms while running 20psi. I shared this info with Tom and he is also doing the tune adjustments on the tunes he does.

Return style fuel system.. When you cant get enough fuel using the returnless system the only alternative is going to a custom return style system, just like on a diesel. Right now there are no kits, so you pretty much have to build your own from scratch... when ever we get a good write up on it I'll copy/paste it to this thread.

That pretty much covers the engine and tranny basics of boosting... next we will discuss choosing you form of FI.

03OrangeSVT 01-08-2008 10:19 PM

Now we look at what form of FI...

There are two choices Turbo and Super Charger, both have good points and bad points. There are also MYTHS that we will look at.

Lets start with SuperChargers


Roots Style

Roots style superchargers are positive displacement, which means they flow the same amount EVERY rotation. This is why they have a little more bottom end but usually start starving at higher rpms.

Jackson Racing JRSC

A good entry level power adder, great for daily driving but are on the small side. You can get around 220whp(SVT) or a little more but since the JRSC has NO way to cool the boost you just start creating heat and as heat increases efficiency goes out the window.

Do NOT expect to go out and beat on Vettes... you'll get your feeling hurt. BUT the JRSC make both the Zetec and SVT funner to drive.


A great setup, PW took it one step farther than JRSC by using a water to air cooler for their boost... which allows you to run more boost safely. As an added bonus they opted to use a larger blower so you get more power and its makes power longer. I have seen a couple of PWSC in the 280-290whp range. But as with ALL superchargers it takes power to make power... which relates to roughly a 20% (or more) loss in power .. since the faster you turn the PWSC the more power it takes TO turn it.


Both are Centrifugal SC's... basically a belt driven turbo.. but they dont hit like a turbo. Both of the SC's make less low end than the roots blowers but they also are capable of making MORE power.. where they flow more air the faster you turn them (unlike roots style blower)

Vortec uses an air to water intercooler that depends on an electrical pump to circulate the cooling water... if it quites you dont cool.

ProCharger uses air to air but its mounted UNDER the car instead of up front like a turbo.

BOTH systems can be fitted with front mount intercoolers, which is the best way to cooler your boost.

Both Vortec and Procharger will perform about the same, both have good top end and are very linear (as are roots superchargers) when it comes to making power.


All turbo's act the same, so I'm going to lump them all together.

A properly sized turbo is a beautiful thing on a car, fast spooling and making big power at lower rpms (since they are not belt driven they make there power sooner) turbo's by far make more power than the available superchargers on the market.

A turbo is also easier to upgrade the boost on, instead of changing a pully and belt like a SC you can normally just turn a knob on your boost controller.

Turbo LAG... modern turbos do not have turbo lag, older ones did the newer ones do not. What alot of people PERCIEVE as lag is the way a turbo comes on, as soon as you hit the throttle you can see boost on the boost gauge so that alone tells you there is no lag.. BUT turbos hit so hard they feel like it all comes at once and most people dont even notice that the boost starts building immediatly.

Turbos are easier on the motor in some ways but harder in others.

The easier ways are they dont put excess stress on the motor since they are turned by the exhaust gases instead of a belt.

The harder is they hit full boost sooner than a SC so you are putting more stress on the system sooner instead of coming on throughout the whole rpm range like a SC.

ALWAYS REMEMBER you need to choose your SC/Turbo depending on your goals

You can go to and use their formula's to figure out what size turbo you need, and you can learn how to read compressore maps.

I HIGHLY recommend that EVERYONE read their turbo tech parts 1,2 and 3.


For off the line... Roots SC's are a little quicker (unless you master pre-loading the turbo like I have) Since they move the same volume with every rotaion they will always make the most low end power.. but this also limits the top end performance.

You have 2 SVT's a PWSC and a Turbo car (GT28Rs) running the same boost level.... the PWSC car takes off and will pull the turbo car at first, but the turbo car will pass it ... how you ask?? Where the PWSC car wont make peak boost until close to redline the turbo car will hit peak boost around 3k rpms... a full 4k rpms sooner. Boost will also cause your motor to rev FASTER... so not only will the turbo car benefit from full boost sooner it will also rev faster for the entire 4krpms.

Centrifical SC's dont have the advantage of the bigger bottom end like the Roots do, simply due to their design. They are designed to flow more air up top, hence giving them the capability of 300whp and more. Their down fall is the lack of bottom end power.. low flow at low rpms because of being belt driving, bu they usually make up for it on top.

ALL FI can be used the same way... you just have to learn how to drive it.

Example Autocross... A turbo car can be just as competitive as a SC car, you just have to learn how to take turns and adjust you full throttle points.

BUT when it comes to drag racing.. especially 1/4 mile the turbo will rule... see earlier example about boost and spool time.


This one is so easy... the bigger the better. Your engine is basically an air pump the faster it goes in and comes out the better it will perform. Usually 3" exhaust is the way to go.. since its hard to put anything much bigger under a Focus.

There are 2 things you can do to help your exhaust flow better.

1) Ceramic coating... its pretty, its expensive and it does help keep the exhaust gases flowing. It also will bake off if its not properly done and it scratches easily.

2) Header wrap... this is by far the best method. Its cheap, looks tough and insulates the exhaust piping way better than ceramic ever thought about doing. If you "PROPERLY" install header wrap it will last for years. I generaly soak mine for 10 minutes prior to install AND I stretch it as I install it while using a 50% overlap.


two headers 1 ceramic coated and one wrapped, you touch the ceramic header and you loose skin and hear bacon frying... then you touch the wrapped one.. you can leave you finger there quite a bit longer AND you dont loose any skin in the process.... why??? INSULATION.. the header wrap just far out performs the ceramic coating when it comes to holding in heat... and hot gases flow faster.. faster gases mean better scavaging which in return ends up making more power.


You can either try to tune it yourself with something like the SCT ProRacer, Sniper's SST, or eventually DiabloSports upcoming tuning software.

Or you can take it somewhere to have it tuned... take it somewhere that they have done Focus's before.... the Focus is ... different that tuning a Mustang.

If you feel comfortable with yourself... you should try tuning it yourself, its a great learning experience and there are plenty people on the forum that will help you.

Well that covers the BASICS... feel free to add "HELPFUL" information... if you start a pissing match you will have your posts deleted and I will see you get at a minimum of an infraction.

This is a "HELP" thread, not a debate.

mpsii 01-08-2008 10:41 PM

Kudos... Nice writeup!

illinipo 01-08-2008 11:09 PM

Thanks a lot John, this thread will definitely help me decide wether to boost the Focus or get an Evo post-graduation [thumb] at least as far as power goals go.

Could you post a somewhat empirical list of 1/4 miles times and whp/wtq numbers for given levels of turbo boost at 9:1 compression? SC times should be a lot different, since for a SC less boost makes more power than a turbo generally...right? (and the torque curves are WAY different)

Also, could you give us some insight to what application a given setup would be best for? For instance:
JRSC - more fun daily driving (you already said this one [hihi])
PWSC - autox
built PWSC - track
small turbo (gt28rs or smaller), stock motor - autox/street
small turbo, high boost - track/???
big turbo (T3 Super 60? bigger?), low boost - ???

Also, what is it about tuning the Focus that is so challengeing? If I boost this car, I definitely plan on giving it a try on the stock motor/low boost. If I blow it, then I will build the motor, but if not, then [grinking]

And if you would grace us with even more of your valuable time and knowledge while you sit at work (erhhrrrmmmm.. [poke] lol), are there any good turbo options from somewhere other than our friends at Garrett? Like Holset, turbonetics, K Turbos, etc...?

Turbo Turtle 01-08-2008 11:13 PM

very nice write up john. thanks that must have taken a while.

you really should sticky this. there are tons of people that get on here and ask all the questions you just answered. sticky that bitch.. your pimp hand is strong, i think it deserves to stick.

Nereus78 01-08-2008 11:25 PM

Thank you for posting this....someone please sticky!

EDIT-remember...he said this is the BASICS...there IS more to it...the search button is your friend. Now GO!

Turbo Turtle 01-08-2008 11:27 PM

you forgot the return style fuel system. seems that not many people have ran one. i dont want to post any info on it until mine works. once it does work, i will post up some info on it. i dont want to look like an idiot, lol.

i am doing it because it seems to be a good alternative to all the trouble that comes with the stock system. tuning trouble, boost a pump, acceleration starvation caused by g-forces on the fuel.

03OrangeSVT 01-08-2008 11:36 PM

Added a small blurb about return style fuel...

and I'm setting here at the house doing this for you guys.

AerofurySC 01-08-2008 11:37 PM

Doctor of all things Boost, Thanks for the post. Great information for everyone!

Turbo Turtle 01-08-2008 11:39 PM

you want me to do a write up on mine when ever i get ready to install it?

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