If you are new, read this info on getting started

[mkoebra95]

It comes up very frequently:

"I saw (or read about) a turbo setup that was making killer power at low boost and I want something similar"  

-then you check the aftermarket kit prices and $hit yourself-

"Maybe I'll do this the cheap JY holy snail route."

So you post something like:

"I'm new here and I want you guys to tell me EVERYTHING I need to KNOW to pull off a JY turbo setup"

Or so the majority of peoples' first posts go.  Occationally someone will do a search of past posts or come into this with a little more knowledge on the subject, but lets face it most of us start off pretty much in the dark, only knowing that the draw of cheap turbo power is attracting us like a moth to a flame.

You come on this board, read some posts in the archives only to be slammed with a bunch of terms like AR, CHRA, compressor trim, pressure ratio, wastegate etc  and you end up like this :confused: :confused: :confused:

-or-

You post your first post seeking the help of people who've done this before and some "mean old school" Turbmustangs poster like 91lx_by_MORA,  Turbostangman or Traction Issuez tells you to pack sand and do a search because the TANSTAAFL rule is in effect (there ain't no such thing as a free lunch).  I can tell you as someone who's been here for a while that seeing a new poster basically ask for someone else to do their homework for them shows two things: you don't know what you're getting yourself into, and (based solely on your first post asking someone to do the research for you) you probably don't have the desire to do all of the work associated with one of these junkyard buildups.  That last part may sound crass, but designing and building one of these projects is an INVOLVED process filled with ups and downs that requires A LOT of patience and desire that no amount of great advice and help from experienced guys on this site will make up for.  Take it from me personally, I started planning my first project over a year ago, and I'm just now starting to cut and weld metal for my headers :mad:.

So you feel shunned and a bit silly for not knowing anything, maybe this turbo stuff isn't for me...

Not to worry!  Here's the closest thing to a free lunch you're going to get!

[mkoebra95]

BASIC KNOWLEDGE

You should come to the table with some basic knowledge, otherwise all the advice on which Turbocoupe T3 or Powerstroke Turbo to buy or which headers to use will be useless.

If you only have time to read one thing, read the Turbo Bible on the main side of this site.  It has enough general information in it to get the most clueless umoung us well on their way to understanding what is going on in a turbo system.

There are also some great books out there.  I've read and highly recommend Maximum Boost  by Corky Bell.  As the subtitle to the book implies, it will walk you step-by-step through designing, testing, and installing a turbo system in any gasoline powered car.  Some of the info is aging, but it is an outstanding read for anyone interested in turboing their own car.
 
Additionally,

Turbochargers by Hugh MacInnes is highly recommended.  I haven't read it, but a lot of people swear by it.

(I only put a link to Amazon.com for illustrative purposes, buy the books whereever you want)

Finally, if you need a quick referrence to some of the terms like AR or CHRA, or if you want to know how to figure the trim of a Garrett turbo you scored from eBay or the junkyard, this link to Garrett will help.

So now you have the basic understanding of what's going on and are ready to start planning your turbo project.

[mkoebra95]

Deciding YOUR Goals

I put the "YOUR" in italics for a reason.  You need to set some goals early on.  Nobody can decide for you between wanting a 400whp daily driver twin turbo 5.0 or a huge single turbo on a Dart block 331 stroker that pushes 1000whp and is the terror of the local 1/4 mile track.  I'm not going to elaborate much more on this, but setting the power or ET goal early on will help point you in the direction.  

If you have a rear wheel target, most, if not all, of the calculations are based on brake horsepower (engine power).  You can estimate your required BHP from a RWHP # by dividing the RWHP by .87 for a manual (13% loss) or by .84 for an automatic (16% loss)

[rant]I know, a writer in 5.0 and Super Ford told you that you can expect a 45% (hyperbole used for illustration) drivetrain loss since the $300 part they bolted on didn't give stellar results on during the post install dyno run they made and they want to keep their advertisers happy.  My reading on the subject, TIME AND AGAIN, shows engine dyno to chassis dyno loss between 10 and 15 percent for manual transmissions, favoring the 10 to 12 range.  I've not seen any B/A automatic #'s, but their RWHP # are slightly lower than similar manual equipped car, in the 2 to 5% range.  If you have before and after engine/chassis dynos and your loss was greater, please tell us.  

Every percent lost through the drivetrain means two hugely negative things to Ford or GM: lost MPG/useable horsepower and heat that the drivetrain must dissapate.  I don't think Ford, GM or any car company would put a drivetrain under a car that eats 25% of the engine's power (AWD/4WD aside): that would kill their CAFE and shoot transmission and rear end warranty repair costs through the roof![/rant]


Twins or Single

The reader's digest answer for "should I go with twins or a big single" is YES.  Either will get you to your horsepower goal.  It comes down to a few basic choices:
1.) Which side of the system (exhaust or intake) do you want to make more complicated.
2.) How much space do you have under the hood?
3.) Are you willing to loose some of the accessories like power steering?
4.) WRT 2&3, do you mind cutting up the inner fender on your precious Mustang to make more space to retain that cold AC etc?
5.) How available is/are the turbo(s) you can reasonably get your hands on (meaning used from the JY/eBay for cheap or new through one of Turbomustangs.com's sponsors for big bucks)
6.) For the racers, would going twins make my car illegal for the class of racing I regularly do?

#6 is the easiest, if you race, read the rules about power adders and decide based on that.

For #1-4, the best way to help you make decisions on these questions is to look at other people's triumps and failures to see which one(s) you like, then visualize how that setup will work on your car.

Visit the links to people's cars on the main side of this site.  There are a lot of great examples in those links.  Additionally, visit http://www.toohighpsi.com for some other examples.

If you read 5.0 and Super Fords, look at the June 04 issue on pages 44 through 48 and 168 through 178 and you'll see three outstanding examples of turbo Mustangs.

First, the screaming yellow LX notch on pages 44-48 and the black $150000 206mph Fox on pages 168-173 use a big single setup to get to their goal.  With both of them, you can see on what I mean by the hot side being more complicated on a single system, since you need to pipe the exhaust gases from both cylinder banks into the turbo.  You'll need to fab up a cross over tube from one side to the other, which requires some work and skill with a welder.  Additionally, to keep a dual exhaust setup similar to the stock setup, you'll have to make a Y pipe where your H or X pipe now lives, again more work with the welder, but definitely doable.  Even if you go with a single exhaust, you'll be making your own downpipe back exhaust system.

The plus side is, the intake consists of one long tube (or sections of tube) from the compressor outlet through an intercooler (or not) to the throttlebody.  Hence the intake side is relatively simple.  The MAF (if you keep it) can be mounted in front of the turbo as a drawthrough meaning you can use almost any MAF from C&L or Pro-M that is calibrated for your new injectors.

Jeremy Hedlund's red 10 second Fox GT (pages 174 through 178) uses a twin setup, and he estimates he spent about a grand to get it on the road.  The hot side is relatively simple, with a couple of flipped shorty headers and section of tube with a T3 flange welded to each.  The downpipes can usually be made to match up with your stock location X or H pipe.  Overall, the exhaust "hot" side is relatively simple.

The cold side on the other hand will need to merge the charge pipes from both turbos into one before the MAF or throttlebody.  You can accomplish this with a Y pipe if you aren't going to use an intercooler, or you can merge them into either side of your intercooler and have one outlet from the IC.  

You'll need to buy a blow through MAF such as Pro-M's Universal to work with this setup, since you have two sources of intake air.  I'm sure the 50lb heads amoung us can figure the MAF transfer function need to use a single MAF mounted in front of one of the two turbos, or some way to add two MAF signals into one from a dual MAF setup, but I'll leave that up to someone else to ponder.

From my reading on this site and the Yahoo JYturbo group, the general consensus is a single turbo system on a V engine is a little more work than a twin turbo setup.  That can be debated, but my little explanation above can give you some food for thought to help you make up your own mind.

For #5, it is a simple fact that the decision on single or twins for most of us will be made based on our resources, namely money.  Used T3s and similarly sized “other” turbos are about $100+-$50 and are readily available in most junkyards or on eBay.  Big singles in the JY may not be much more expensive than a T3, but (at least in the JY’s I visit) they only come around once in a blue moon.  On eBay, T04s run for about twice to three times as much as a T3.  If cash is not a problem, then I’d suggest going with (a) new turbo(s) from one of Turbomustang’s sponsors.

[mkoebra95]

Selecting the Correct Turbo(s) for Your Turbo Mustang

From this point on, I’m referencing twins to make the English easier on me and less confusing to read: no more “turbo(s)”, just “turbos”.  What I’m writing can be applied to singles or twins.

There are several things to consider when selecting the turbos.  Basically, it can be broken down to:
1.) which brand (ie Garrett, Holset, IHI etc)?
2.) what type in that brand (T3, T3/T4 hybrid, T04B, T04E, GT etc for Garrett alone)
3.) which compressor trim to use?
4.) what compressor AR?
5.) what turbine trim?
6.) what turbine AR?
7.) Do you want an oil and water CHRA or an oil only CHRA?

#1 and #2 are going to be up to you.  If you are going with a single and a nice Holset that fits your needs comes along, grab it.  If you want to be like (guessing) the majority people running a JY twin setup, then you’ll likely be using Garrett/AiResearch T3s or similarly sized IHIs from OEM turbo cars.  The choice is up to you, but the rest of this section relates specifically to Garrett T3 and T04s.

#3 Choosing a compressor trim.  

You probably noticed from the Turbo Bible that there is some complicated math to be done when choosing a compressor blade.  You’ll need to know your engine’s naturally aspirated VE, the bore and stroke, the pressure ratio you plan on running, how to do logarithms, square roots then you have to know how to read a compressor map etc etc.  There are enough math calculations to make your high school/college math teacher’s head spin :confused:, when doing by hand that is.  

Lucky for us, in the age of computers and Javascript, there is no need to do any of these calculations by hand, and the term pressure ratio can be thrown out in favor of the term most of you want to use anyway: a boost PSI.

You’ll need to have your horsepower goals, engine VE and desired boost level handy, then proceed.

[mkoebra95]

What’s my engine’s VE

Here is a list of the stock VE #’s for some of the more common V6 and V8s used in Mustangs.  I even threw in some #’s for you GM guys who don’t have a turbo site as cool as Turbomustangs.com to call your own

Fox/SN95 5.0L GT, assuming 215bhp/288ftlbs:
Bore: 4.00
Stroke: 3.00
VE@ peak HP(4200rpm): 76.16
VE@ peak torque(3300rpm): 81.60

4.6L 99+ 260bhp PI GT:
Bore: 3.55
Stroke: 3.54
VE@ peak HP(5250rpm): 79.18
VE@ peak torque(4000rpm): 91.93

4.6L DOHC 305bhp 98 Cobra
Bore: 3.55
Stroke: 3.54
VE@ peak HP(5800rpm): 84.08
VE@ peak torque (4800rpm): 91.33

3.8L 99 Mustang 190bhp
Bore: 3.8
Stroke: 3.4
VE@ peak HP(5250rpm): 70.00
VE@ peak torque (2750rpm): 81.00

96 LT1 Camaro 285bhp
Bore: 4.0
Stroke: 3.48
VE@ peak HP(5000rpm): 73.17
VE@ peak torque (2400rpm): 79.43

LS1 Camaro 305bhp
Bore: 3.90
Stroke: 3.62
VE@ peak HP(5200rpm): 76.16.
VE@ peak torque (4000rpm): 82.82

My Bolt On Modified 95 Cobra HP #’s taken from a dyno session (262whp/300w-ftlbs):
Bore: 4.00
Stroke: 3.00
VE@ peak HP(5250rpm): 84.5
VE@ peak torque (4000rpm): 95.1

This info is needed to help you match a compressor to your application.

[mkoebra95]

Matching the Compressors to Your Engine

Open this page in a new window:
http://www.turbofast.com.au/turbomap.html

You’ll notice that there are some boxes to enter info in.  Take the #’s I supplied above for your engine and plug them in.  

-Start with “Point #4” and enter the following (the boost threshold for your engine (where 1psi will be made) I chose 2800rpm for my Cobra,
-1psi for the boost,
-VE something less than your peak VE (a guess on most engines, but mine is 82 (enter VE and any other percentage as a whole number)
-start out with a compressor efficiency of 70% (entered 70)

-Move to the #3 point, and enter the RPM your engine makes peak torque
-enter the max boost you want to run (9psi) in my case
-the VE from above for your engine (95 for me)
-70 for the compressor efficiency.

-Move to the #2 point, and enter the RPM where you’re engine makes max power,
-the max boost
-the VE
-use 70 for the compressor efficiency.

Lastly for this section, enter the redline rpm, boost, VE (it’ll be something horrible like 55%), and compressor efficiency.

Enter your Bore, Stroke, # of cylinders (note, if you are doing a twin setup, you’ll divide the total # of cylinders by 2 and use that # since each turbo will use one bank), and the air temp in deg C (just use 20).  For the intercooler efficiency, I use 85% (entered as 85).  If you aren’t going to use an IC, then deselect the intercooler block at the top and don’t enter anything here.  Once all of those #’s are entered, then hit the “calc” button.

Using my engine, you’ll notice the 40-trim map is a horrible match.  You want to see most of your points near the center “island” for max efficiency.  Since this compressor isn’t good enough, hit the “Next Map” button, and the next biggest compressor comes into view, and so on, until you come to one with most of the points (except the boost threshold) near the center efficiency island.  If you entered my info, you’ll notice that the 60-trim and Super 60 compressors are almost perfect.  

Once you’ve matched the compressor, go back and enter the efficiencies that each point falls on, and you’ll be set.

Ironically enough, the 60-trim compressor is the blade found on ALL 2.3L Turbo Fords, hence the standard answer of “get two Tbird T3s and be done with it”.  

What that one sentence piece of advice can’t tell you is what horsepower you can expect or how much boost you'll need to run to reach a horsepower figure with your combo.  If you look below the compressor map, you’ll see some horsepower figures in the B.H.P. row.  In my 5.0L modified Cobra example, I can realistically expect to see about 440bhp and 500ftlbs of torque.  But Matt, I only see 224bhp and NO torque #’s.  Remember that you have to double the horsepower figure to get your expected horsepower from the max horsepower block (#2 in this example), and you can get your torque by taking the horsepower figure from the #3 block (max torque RPM), doubling it, then multiply it by the peak torque RPM, finally dividing by 5252 (from the horsepower equation: hp = (ft-lbs x RPM)/5252).

It’s really that simple.

[mkoebra95]

Choosing the ARs and the Turbine trim

The next thing to figure out once you have decided on the compressor trim, is the ARs to use.  

Here is a section that you can potentially screw up your results by not keeping things in your horsepower goal and the intended use of your car's perspective.  A huge 1.15 AR T04 turbine housing will not help you out if you only want a 400rwhp 5.0L street stang.  You won’t see boost until the upper RPM range, and I’d bet your car will act like a centrifugal supercharged car and build boost with RPM until max boost is reached at redline, if it spools at all.  

On the flip side, if you have a stroked 351, then those two little 45trim .42/.48 AR Garrett T3 turbine housings from two JY Saabs will likely render your setup a 4000rpm and below stump puller, when you wanted a high RPM strip terror.

I don’t have any scientific info for you here, but as a rule, both compressor and turbine ARs will be determined by where in the RPM range you want to make your power.  As a general rule, the bigger the ARs, the later in the RPM range you’ll build boost.  Bigger AR housings are less restrictive to high RPM flow, but sacrifice lower RPM boost for making it in the upper RPM range.  Conversely, the smaller ARs will build boost sooner, but will choke off your upper RPM exhaust flow, to some extent.  That being said, if you only want a 400rwhp daily driving street terror, then a couple of .42AR compressor/.48AR turbine T3s will suit you well.  If you want stock 5.0L block splitting power with the ability to spin it to 6500 RPM, then the Tbird .60AR compressor/.63AR turbine housings are probably the smallest choice.  Remember those goals you set early on?

I readily admit I don’t know how to read a turbine map.  I’ll leave that up to someone else to describe or post a link to help us all out.  This would only come into play for you guys doing a single setup as most of the JY T3s have the same turbine wheels.

[mkoebra95]

THE TYPE OF CHRA

The Garretts and most other turbos come in two choices: oil only and oil and water CHRA.  They both have pluses and minuses associated with them.  

Oil Only CHRA

The oil only CHRAs up side is they only require an oil feed line and a drain line to successfully install them in your engine.

The down side is, there is no engine coolant flowing to them to help cool down the CHRA, and some claim they "coke" up more easily.  That's debatable, and I'm not passing judgement one way or the other.

Oil and Water CHRA

The CHRAs that have engine coolant piped to them supposedly offer longer life for the bearings and resist oil coking better than the oil only CHRAs.  Again, this is debatable, but coming from someone who's removed upwards of 30 turbos from OEM cars, most of the of the more recent OEM applications use the oil/water CHRAs.  I don't think car companies add unneeded parts to a car simply for the fun of it.  Saab, Volvo and Ford switched from oil only CHRAs in the OEM T3s to oil/water ones about 1984 or 85.  There must be some advantage to using them :tu:

The downside is you have to run two extra coolant lines to and from the turbos.

Some guys will use the oil and water CHRAs and not hook up the water fittings.  I am not advocating this, but I have seen it done more than once.

The first picture I attached below shows an oil/water CHRA T3 on the left and an oil only CHRA on the right.

FINDING THE TURBOS YOU DECIDE ON

This comes down to how much cash, time and patience you are willing to invest.  You can get used turbos from the JY relatively cheaply.  You just need to know which cars to look in.  There is already a sticky on this, so I’m not going to elaborate about which cars have which turbos.  

If the junkyards in your area don’t have the cars/trucks you need, then check eBay and the classifieds in here.  Finally, there is always the aftermarket companies.  

These choices go from cheapest to most expensive and from the hardest/most time consuming to the quickest/easiest.  It’s all a matter of how much time, money and patience you have, and what your priorities are.  

If you are headed to the JY, do yourself a favor and print out a list of all of the cars that have the type of turbo you are looking for.  Also, take along a complete set of hand tools including but not necessarily limited to: an adjustable crescent wrench (if you are specifically going for turbos from 2.3L Turbo Fords, a 1” crescent wrench will help remove the EGR tube from the turbo exhaust manifold), a full assortment of metric sockets, including deep-wells and normal sockets, an applicable sized ratchet, a breaker bar, a small hacksaw, a hammer, a can of penetrating blaster, some screwdrivers, an assortment of extensions (to get to the downpipe studs, you'll need at least 12", if not 18") and a universal joint.  Oh yeah, bring plenty of patience.  

One thing I’ve noticed pulling the 30 or so T3s I’ve scavenged, with the exception of the Saab 900 T3s, it is WAY easier to remove the whole turbo and exhaust manifold as a unit and then separate the turbo from the manifold, than it is to try to get the turbo off with the exhaust manifold on the head.

In an attempt at full disclosure, I remove and sell used turbos whenever I can get to the JY.  I might be one of the eBayers or guys on here selling things.  I'm not giving myself a shameless plug, but if you buy a T3 on eBay from mkoebra95, that's me.  Tell me you are from turbomustangs.com and I'll give you a discount on shipping.

(moderators, if this plug is not acceptable, tell me and I'll remove it TIA)

[mkoebra95]

HEADERS, FLANGES AND PIPE: MAKING THE EXHAUST SIDE

This isn’t intended to be a huge section.  You’ll need to do a search and find out exactly what other guys have done.  Basically, the Fox bodied guys can flip shorty headers and weld a small extension of pipe to them with a T3 flange on the end.  For a single, you’ll be using the headers, but routing pipe from each header to a merge collector to mount the turbo.

For the 4.6L and SN95 5.0 guys, we pretty much have to make our own headers, that is if we want to keep all of the accessories.  I suggest making them out of stainless steel pipe (or tube) with mild steel flanges.  Other’s have their own opinion, but that’s what I think.

I recommend using a ½” thick flange at the heads and at the turbos and cast weld ells with pipe (not thin walled tube) but the tube works as well.  The weld ells are cheaper than mandrel bent tubing by a long shot (you can buy 2 headers worth of pipe and ells for under $250), yet they have smooth bends just like mandrel bent tubes.  They are beefier: sched 10 pipe has a wall thickness of .109” compared to .065” for most tubing.  Either way, plan out your headers and buy the appropriate bends or ells and start welding.

You’ll need to make downpipes to connect your turbos to the stock location H/X pipe (you have already ditched that stock POS H pipe right ).  For the single setups, you’ll need to make a Y pipe from the down pipe to mount to your stock dual exhaust, unless you are going with a BIG single exhaust setup.

What’s that?  You can’t weld?  Then I suggest you find a friend that can and offer copious amounts of beer, or buy a welder and learn how.  I chose the second route.  Welding is a blast (no pun intended) and you can use that skill for other projects related to your Turbo Mustang as well.

[mkoebra95]

THE INTAKE SIDE

You can use any type of tube you want for the intake side.  A lot of people use aluminum or steel.  I’ve even seen PVC pipe .  You are only constrained by how much you can afford.  

I would recommend using a decent intercooler.  An IC isn’t required, but keep this in mind, when you compress air, it heats up (you probably know this if you read the Turbo Bible).  If you compress it 9psi over ambient and your compressor is 70% efficient, then the temp will still be some 100 degrees hotter than what the car would normally suck in.  An 80% efficient intercooler will nock all but 20 degrees of that temperature rise from the intake air charge.  Which do you want your combustion chambers seeing: 100degree intake charge (post intercooler) or 220degree air from the compressor without an IC?

You can buy an aftermarket IC, or if you can weld, you can construct your own from an aftermarket blank core or from several junkyard cores.  You’re only limited by your imagination and wallet.

Obviously, your intercooler design will depend on your total system design (single or twins) and how much room you have out front to hang it.

You can likely get by with running an intercooler for each turbo on a twin setup, or with running some big OEM diesel one on a single turbo setup.

If you want to get tricky and can find the room, you can run an ultra efficient air to water intercooler.  These would likely be best run with a single turbo, where you can mount something similar to the Aftercooler used on some centrifugal superchargers.

You’ll need some connectors whether they be silicone or plain rubber.  Figure out where you are going to cut your pipes, then buy the appropriate connectors.  Just remember one thing, any connection should be considered the weak link in your system and a spot for a potential leak.  Connectors can be minimized by cutting and welding bent tube.  

[mkoebra95]

What sized piping?

Here’s a place that you can do more harm than good by going too big or too small.  

Two things to keep in mind, you want to keep the velocity of the charge air below .4 Mach (roughly 450 feet per minute) and you don’t want too much intake volume such that you create unnecessary throttle response lag.

Here are two equations for those of you who like math to keep in mind:

The time it takes to go from no boost to full boost is a function of your total intake volume before the throttle body:

Time = (volume in cubic feet of intake/ CFM of flow out of boost) x ((60 sec/min)/(1728in^3/ft^3)) x 2

Velocity = airflow/area

CFM out of boost is roughly your hp @ a given RPM x 1.5.  The 2 is a 50lbs head deduction that when going from no boost to boost, the airflow through the system doubles).  

So how do you figure the volume of your intake?  Here’s some pointers:  I ASSuMEd that my intercooler was 300 cubic inches.  Also, I made an educated guess that the total length of the intake piping would be about 9 feet.  If you want to get anal, you can estimate the small diameter from your two turbos into the IC, then the distance of the larger pipe to the throttle body.

For piping volume,  V = ((diameter of pipe/2)^2)* 3.14159* length of pipe in inches

2” pipe x 9’ = 340cubic inches
2.25”pipe x 9’= 430 cubic inches
2.5” pipe x 9’ = 530 cubic inches
3” pipe x 9’ =  763 cubic inches

Plugging into our time to fill, plus adding the intercooler volume of 300cubic inches,

2.00” pipe x 9’ = .244 sec
2.25” pipe x 9’= .275 sec
2.50” pipe x 9’ = .311 sec
3.00” pipe x 9’ =  .393 sec
3.50” pipe x 9’ =  .491 sec

What does this mean?  If you choose to use 3.5” piping in your system, and are run up on by some ricer in a Fast and the Furioused stickered out STi, it’ll take ½ a second to go from no boost to full boost for your little 60mph to "show him who’s boss" mph.  That ½ a second can seem like an eternity when you really need it.

The flip side of this is that going too small can cause unwanted turbulence.  For most of us that will only reasonably need 750cfm for a 500bhp 5.0, then the following velocity of the air charge applies:

2.00”: 573 fpm
2.25”: 453 fpm
2.50”: 367 fpm
3.00”: 255 fpm
3.50”: 187 fpm

Remember that you want to keep the velocity below Mach .4 (450fpm) so in the case of a 500bhp 5.0L Mustang, 2.5” pipe from the intercooler to the trottlebody is the smallest tubing you should run.

[mkoebra95]

Do I  really need 72#/hour injectors for my 400rwhp Turbostang?  

Can I get by with my single 190lph intank pump and and 36#/hour injectors plus an FMU on my 600rwhp turboed 351?  

I hear the Turbocoupes used 35#/hour injectors, so can I use 8 of them in a mild turboed 302?

I chose those questions specifically, and I'll try to tackle each in turn.

There are two parts of the turbo system that I'm going to cover here which IMHO you ABSOLUTELY should not skimp on: the fuel system and the oil system.

This section is dedicated to turning dead dinosaurs into noise (an old Naval Aviator saying ).

Fuel Injectors

What size do I need?  

Here is the equation to figure the required injector size:

Injector Flow Rate (lb/hr) = (Engine HP x BSFC)/
(Number of Injectors x Injector duty cycle)

Get out your calculators, open an Excel spreadsheet or the little Windows calculator...  Better yet, let's let some Javascript do all of the math for us

Open this page in a new window:

http://injector.com/injectorselection.php

Remember those goals we set at the beginning of this discussion?  You'll use them again.  Better yet, use the numbers you figured from the Ray Hall Turbocharger page when we matched the compressor map to your application.  I'll use my 440bhp 5.0L Cobra example.

Enter your expected brake horsepower (not rear wheel hp).  To convert a RWHP to BHP on a manual car, divide your RWHP by .87, for an automatic tranny, divide by .84 for your BHP.

Enter that # in the Engine Horse Power(1) block

For the Brake Specific Fuel Consumption BSFC(2) block, change it from .5 to .6.  I've read that .6 is a good number for forced induction and .5 for naturally aspirated, this can be debated and you can likely change it in your EEC Code once you start tuning.

Enter the # of injectors: 8

I would change the duty cycle to .85 (percentages are entered as a decimal with this calculator, meaning 85% is entered .85)

then click "Calculate the Injector Flow Rate"

For my 440bhp twin turbo 5.0 Cobra, I'll need about 39#/hour injectors.  Aint that cool: the exact size used in the Lightning and 03 Cobra (depending on which fuel pressure flow rate Ford used that day, they used to be called 42#/hour, but at a higher base fuel pressure).

Remember from your High School math, that if you make the top numbers bigger (ie go from 440 to 500bhp or raise the BSFC from .6 to .7) or bottom #'s smaller (lowering the duty cycle) then it'll tell you you need bigger fuel injectors.  Obviously, algebra tells you the opposite is true as well.

Since most of you probably want to know just how much the 42#/hour injectors you're going to buy can handle, since we are never satisfied with a horsepower level for too long, change the BSFC to .5 or .55 and the duty cycle to .90.  Then, progressively enter larger engine horsepower numbers untill the bottom flow numbers hit 42#/hour.  I wouldn't personally want to run a car with close to a wide open duty cycle (near 1.0 meaning always open), but it's your choice.  Once you get your setup running, and if you have data logging capability, you can see just what your injectors duty cycle is, and therefor how much room you have to grow.

Basically, you're looking at 550bhp to 600bhp stock block splitting horsepower with a .50 to .55 BSFC and a 90% duty cycle.

FMU, Engine Tuning and Calibrated MAFs

I'm going to get a little controversial here and probably pi$$ off some of the old school guys.

My personal opinion of using FMUs to force those "undersized" injectors to work in your system and/or relying strickly on a MAF for injector calibration is don't do either.  As I said at the beginning of this section, I wouldn't advise going the cheap route with the fuel system or the oiling system.  Skimp on the 5' tall shopping car wing or carbon fiber dash inserts (oh wait this isn't Superhondaonline, sorry).  Put off the new paint job or interior upgrades to afford the best parts in the fuel system.

FMU
 
Someone else can better elaborate on using an FMU.  Corky Bell advocates them in Maximum Boost for engines running less than 9psi, and I disagree with him here.  He's the expert, I'm just the average Joe (or Matt in my case) who's done current research with what's on the market today, vice 1997 when he wrote that otherwise outstanding book.  Basically, an FMU raises the fuel pressure at the rails as the boost level rises in a certain ratio.  What it does is force those little 24 or 30#/hour injectors you already have for your killer naturally aspirated ride to act like bigger injectors, running at fuel pressures they were never designed to operate at.  Yes it will likely get you by, but it supposedly makes electronic tuning harder, and your fuel mileage and idle will likely take a $hit too (according to some reading I've done).  

If you just have to use an FMU and small injectors because your stuporcharger buddies do, or if funds are really that limited, then here's what you can do to figure out how those injectors will act:

FMUed up injector flow = (square root(new pressure divideded by the original pressure)) x injector size

Your stock pressure is about 40psi give or take 2, but I'll use 40 for simplicity, and lets say you have a 4:1 ratio FMU, 24#/hour injectors, and 10psi of boost.  Your little 24#ers will roughly act like 36#/hour injectors:

sqrt((40+4*10)/40)*24 = 34#/hour

Whatever.  I readily admit I don't know much about FMUs because I choose not to.  They appear to be a bandaid solution to me, so I'll leave a better explanation to someone else.

Using a MAF by itself to "Calibrate" for bigger Injectors

I'll say this at the onset, I think you should run a MAF that is calibrated for the injectors you plan on running.  This way the MAF signal that is plugged into the EEC's transfer function (described in detail at http://www.pro-flow.com) will be big enough to  handle your higher horsepower level.

"But I thought you just said don't run a MAF calibrated for the bigger injectors alone?"  Yes, I did, and advocating running a calibrated signal doesn't invalidate that statement.  Read this:

http://www.mustangworks.com/articles/electronics/InductionBlues.html

Reader's Digest version of that link: the wider the variance from the stock injectors your aftermarket MAF is calibrate for, the more problems you are going to have.  According to the article, aftermarket MAFs "calibrate" by multiplying the signal times the ratio of the stock injectors divided by the new injectors.  In our case, 19/42.  That leaves A LOT of room for error in the upper RPM range.

So what else do you need to do to solve that problem?  I advocate changing the EEC programming to incorporate the bigger MAF transfer function (again Pro-M, at http://www.pro-flow.com will describe this better than me).  This is the way that Ford calibrated for the 24#/hour injectors in the 94/5 Cobra: the stock MAF is identical to the GT's MAF, yet the 5.0L Cobra works just fine with the 24# squirters.  They also do it this way on the Lightning, and other years Cobras and damn near every other car they've make/made.

But how do I change the EEC code?  Use a custom chip, an EEC Tuner or TwEECer, or one of the stand alone computers like the AEM unit.  I'm not going to elaborate any more on this since this is only a partial free lunch.

As far as which MAF to run, I am a big fan of Pro-M.  I'm personally going with a Pro-M Universal or similar blow through.  As I mentioned in another post, you'll need something like this for a twin setup.  A drawthrough like the Pro-M 80mm should work for a single setup.

Fuel Pumps

Consulte your favorite FAQ on this.  Basically, according to a chart in Maximum Boost a single 190lph pump on its own can support ROUGHLY 500bhp. I AM NOT ADVOCATING RUNNING A 190lph PUMP BY ITSELF FOR 500BHP.  The same chart claims a 255lph can support ~700bhp.  Again, these are way higher than I've seen, and remember that as the voltage at the pump drops, as I've read it does in the upper RPM range, the flow rate, and thus the HP it can support drops.  If someone else finds a decent chart, I'll include it here.

At any rate, a decent 255lph intank pump will only cost about $120.  Remember that theme of not skimping on the fuel system?  Just spend the money and be done with it.

Junkyard Fuel Injectors

Yes, the later years stock 2.3L (roughly 86 up) Turbo Fords used 35#/hour brown top injectors.  Unfortunately for us, they are low impedance or peak and hold vice the high impedance injectors our EEC uses (both 5.0/4.6L Fords and the SBC).  

What this means is you'll need a resistor pack or injector driver to run these injectors or similar ones.  I've been told that you can rob these parts from Volvos and older Hondas, if you just have to push your luck with junkyard injectors.  Some guys even find a bunch of throttle body low Z injectors from early 80s SBF and SBCs to run.  I've read they range from 40 to 56#/hour.

I've also read the the RX-7 ran 42#/hour high impedance (resistance) injectors in it.  That's sweet, but good luck finding a wrecked one in a junkyard, let alone enough of them to piece together enough working injectors for your V8.

I'll just say this and leave it alone: do you really want to push your engine's health on some 15+ year old injectors and a junkyard rigged injector driver setup?  Put off buying that new Playstation or give up beer & fast food for two months and invest in some new properly sized injectors.  Steeda and other aftermarket companies sell the Bosch 42#/hour injectors for about $300.  Here's a reoccuring theme: don't go cheap on the fuel system.

[mkoebra95]

Here is a picture of a couple of .60/.63 60 trim Tbird T3s in a relatively normal mounting position for a twin turbo V8.  You can also rotate (not talking about clocking here, more on that below) the turbos so that the turbine inlets' relative position to the head is different, but you'll notice a problem using the stock Tbird swinggate/internal wastegate housing: one points down, like you want it, and the other points up, sending the down pipe into the hood!  Not COOL!!

[mkoebra95]

There are several solutions to the swing gate problem.

First, you can block off the internal wastegate section with a plate, and run aftermarket external wastegates.  This is expensive, but an excellent solution that offers HUGE room for future power increases.

Second, if you can weld cast iron, you can cut and weld the stock Ford elbow whichever angle you want.  This offers a great flowing housing, IF you can weld cast iron.

Third, you can use one of the other OEM swing gates from a Saab or Volvo.  These are cheap.  The Saab 9000/Volvo ones offers a beveled downpipe mounting surface like the Ford unit for excellent sealing.  This is a decent solution for those of us with cramped engine compartments (5.0/4.6 sn95 anyone?).  The drawback is they don't flow as well as the Ford units.

Lastly, you can use your imagination and come up with some other solution

[mkoebra95]

If you've decided on some smaller turbos like two 50 trims with .42/.48 ARs, you will be looking for them in mid 80's Saab 900s and or 9000s and Volvo 740s or 760s.

In the junkyards I go to, the bigger Tbird T3s are becoming scarce.  The word is out on them, and there just aren't all that many of them to begin with.

Not to worry, other T3s will work, and are still relatively widely available.

The Saab units use a standard T3 flange and the internal wastegate housing matches the Ford 5 bolt pattern.

Volvo uses (or used) a different turbine inlet, pictured at the top below.  The bolt pattern is smaller than the "standard" T3 pattern.  If you need measurements, ask, and I'll post them.  The internal wastegate housing uses the same bolt pattern as Ford and Saab.

To remove these, you will need to take off the exhaust manifold.  The T3 bolts to the manifold from the back side, and it has a locking plate on it.

You will obviously need different flanges to run the Volvo units.  I have seen these flanges for sale from aftermarket companies, just make sure you specify which flange you need.

So I have my turbos, should I rebuild them or run them as-is?

Unless you can reasonably determine that the bearings and oil seals are good or that the turbo has recently been rebuilt, then it is a smart idea to rebuild the CHRA.  When you remove the turbo from the OEM car, look in the intake piping and compressor housing for oil.  Some oil is fine, but if you get more oil out of the turbo/post turbo intake piping than you do from your engine when you change your own oil, then the oil seals are shot.

Also, spin the turbine shaft and wiggle the compressor blade side-to-side and feel for excessive movement.  If the blades don't spin freely and either compressor or turbine touches its respective housing when you wiggle it, then the turbo is likely shot.  A free spinning turbine shaft with a small amount of side to side play is normal.  In and out play is a bad thing.

The T3 I pulled has some #@%^$# cracks near the wastegate hole!

Not to worry, this is normal, and most all T3s will develop these cracks over time if an internal wastegate is used.  As long as the cracks aren't so big that they go outside the wastegate housing area and you can see light through them, they are fine.

[mkoebra95]

One of the cool things about the Garrett/AiResearch T3 is you can clock the housings.  This means you can rotate the intake and exhaust scrolls a full 360 degrees to meet your needs.  

[timmyturbo]

Wow, informative.  This answers most if not all the basic questions.  
[Edit] he covered what i mentioned here- No longer necessary. [/Edit]
 :tu:

[Stang Seller]

This will definitely be a good read for the noobs and hopefully keep this section from the 1 billion new threads entitled "What Turbo Should I Use???".  And I think that GTPTim makes a good point on the MAF as well, what brands to use and which ones to stay away from.  As for fuel demands, I think everyone running any sort of power adder in a Mustang should be running at least a 255lph intank pump, and its pretty easy to find out how much power each specific injector size will support.  Maybe a quick description of the sizes and power rating next to them?  
Very well done tho MKOEBRA95!!
SS

[mkoebra95]

If you guys notice anything blatently wrong, or if you have some stuff to add, PLEASE DO IT.  I appreciate the thanks and suggestions.  I know there are others out there who know more about some of these things than I do, especially the single turbo stuff since I've spent the better part of a year researching and designing my twin setup.

[mkoebra95]

Anyone else have anything to add to this?  Does anyone think this should be a sticky?

[bleeatch]

Does anyone think this should be a sticky?

I do, there is alot of good info in your right up and will be alot of help to new people

[grampshandmedown]

I just wanted to take a minute and thank you soo much for all of us newbies...

I hadn't planned on joining the site officially until I came up with a few questions, but was already feeling a bit overwhelmed by all the seemingly endless knowledge.  You have really given us a great foothold!

Thanks
B.J.

[westexgt]

The only question I have is the fuel part.  I am currently building a twin turbo setup, looking for around 450 HP on a near stock 5.0 I am confused on what I need to do with my Fuel system.  I know I need around 42# injectors, 255lph fuel pump, and a Pro-M maf.  But what else???  Also thanks for all the info.  You did an awesome and quick job of getting down all the basics.

Kevin

[MagicBus]

you answered your own question.. for that h/p goal you would want to pick up..

42lb injectors
GSS340 Wlabro pump  (255 lph hi presure)
ProM Maf ( calibrated to 42lb injectors)

Thats it!

[Stang Seller]

Wouldnt 42lbers be a bit overkill for 450 HP?  At 450hp I would suggest sticking with 36 lbers.  Unless you're talking 450RWHP which will be pretty hard on a stock 302.
SS