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The basics of Turbocharging a 4.0 Mustang Design Phase:
Turbo location: The first order of business in the design phase is layout, starting with where you want to mount the turbo. Once the turbo is mounted, you can work backwards with the hot side pipe feed to under the car where it will tie into the manifolds. How you mount your turbo will dictate how you mount your wastegate. The most common mounting position for the turbo is just about valve cover high at the front of the engine bay. Exactly where depends on how much you want to relocate to make things fit. With the turbo in this position, with the exhaust feed from the manifolds and downpipe near parallel to one another, the gate can be mounted right in between them, just under the turbo. This also happens to be the easiest way to set things up as well. If you low mount the turbo, you can plum the gate in just after the manifold Y pipe and vent it into the out going exhaust where they cross paths. This is the design I went with, and although it works perfectly well, it is the most inconvenient due to being located under the car. Don't read too much into that, turbo system are pretty much maintenance free once installed, but if you change boost via spring instead of a boost controller, it is be a pain to get to without a lift or a good floor jack. Pipe routing: Hot Side: I touched on this in the Informational/FAQ. When you route the hot side piping, make sure it does not contact anything. Not even metal beyond the brackets used to hold it in place. The two main things you are going to look for here are the clear paths from the exhaust manifolds to a Y pipe to turbo and then the turbo down pipe to your exhaust system. Thanks to a question by Big Studly, I'm going to elaborate a bit on the exhaust and the use of flex pipe sections. These sections are used to reduce stress put on one sections of the exhaust by another and reduce the amount of vibration and movement transferred from the movement of the engine. They are more important in both factory and aftermarket inline configurations where the turbo flange is integral to the manifold and the turbo is mounted right off the side of the motor. The down pipe will usually have a section of flex in it so the movement of the engine, header and turbo is not impeded by the back half of the exhaust, which is usually quite rigid. If you don't have the flex in place, your header will eventually begin to crack no matter if it's stainless and mild steel or cast iron. In a configuration where you have the turbo mounted some distance away from the headers, flex pipes may be used before or after the turbo and sometimes in both places. Mounting points and over all layout will dictate the best placement. I have tried my best to leave out influence from my build, but in this case I'm going to use the location of my flex as an example. My flex pipe serves only to protect the integrity of the wastegate connection and Y pipe on the incoming side of the system because the pipe that wraps the engine and goes in to the turbo is FIXED solid to the block with metal brackets. The movement here from the engine, especially under hard launching would torque the system and could snap the gate primary or crack the pipes at the Y. On the downpipe side, there is no need for a flex because the pipe goes from the turbo to the first stock exhaust hanger with no solid bracket connections.  Cold Side: If you use a front mount intercooler it can be mounted under the front bumper cover utilizing the bolts that hold the crash bumper to the bump shocks. If you don't go with an IC right away, but plan on it in the future, you could run the piping in such a way that a long 2.5 or 3 inch pipe is in place where the IC would eventually go. This will save fabricating the intake from turbo to throttle body twice. These is no real challenge here. The Turbo location and IC if used will dictate the pipe routing. Just get out the straights and bends, fire up the band saw and get the TIG ready. They bypass or blow off location depends on the MAF location/configuration. If you are going draw through, the MAF will be in a tube that goes in to the turbo inlet. If you are going blow through, the MAF will be in the pipe just before the throttle body, after the turbo. The bypass: will route intake air from between the throttle body and turbo outlet back to the inlet side of the turbo after the MAF. This is so metered air is not lost or measured twice. The Blow Off Valve: will be mounted anywhere between the turbo outlet and the MAF, but never between the MAF and the throttle body. You want to vent the air before it is metered, not after or you will end up with a rich condition on lift and bad fuel economy. .So all the piping is in and the intake is set up as draw through, what now? Run the lines - all the lines: We'll start with the oil feed line first. You can use 4 or 6 AN steel braided line here. Ford cars also do not need a restrictor valve in line to limit oil pressure. Most turbos can only take about 30-40 PSI. Some imports and maybe even some domestics can have 60+ PSI of oil pressure at the sending unit. Pushing that into the turbo is going to blow the seals and smoke your turbo... literally. So under the car on the drivers side of the block you will find the oil sending unit. It's a small white sensor sticking out the side of the block. Unplug the line running to it and remove the sensor. There may be a dribble of oil, but none remains that high in the engine when it is off. After the sensor is removed, install a T fitting that has two ports pointing down. One will take the sensor and the other will take the feed line. Install the line at the turbo (small port at the top of the center section) and you are done. For the Drain, you'll use a 1/2s or 10 AN line braided steel line. There are a few ways to set up the drain. You can go through the top most portion of the pan access panel as Vortec does or you can go in at the timing cover like PH or you can go through what looks like a bung on the drivers side of the aluminum pan assembly (I call it that because the damn mains are bolted right through the bottom of the pan. This is a serious bottom end.) So if you go through the bung on the pan you will need to find a tap for the 10 AN fitting. Drill out a hole inside the bung with a 3/8ths bit. Tap the bung itself for the AN and with ample Teflon tape or some high temp silicone, tighten it in to place. On the turbo side a flange will need to be made for the AN fitting to bolt to. That fitting will be a threaded male 3/8s that will go into the flange and a threaded 10 AN male that you will attach the other side of the drain line to. Piece of cake! That is about the biggest part of the entire fabrication because you have to put a hole in your car where holes are not supposed to go. Next are the vacuum lines. You need two minimum, so that means three off the manifold. One for the fuel sending unit and EGR that Ford intended the port for and two for the Turbo. Remove the line from the manifold and run a line from that port to a vacuum tree (you can get them at autozone or on line.) or find a single in three out T. Once that is installed, plug the original line back in to the first port on the T, and plug two lines into the other open ports. Draw one to the Wastegate Actuator and the other to the bypass/blowoff valve. If you are running a boost gauge and or boost controller, get the appropriate T or tree. I'll let you have all the fun figuring out how to run the lines for the Boost Controller (if in-car) and boost gauge in to the car. Same goes for the AEM wideband. My install on all vacuum lines and wires coming into the interior are non invasive. I did not go through the fire wall for anything. You can find those write-ups by clicking here. MAF relocation: If you ran draw through it is likely you will need to relocate the MAF some distance from the stock location. You can do this in one of two ways. The first way is to get some wire, cut the harness and run the necessary length needed to move the plug to the new location of the MAF housing. The other way, though pricey, is to get a MAF.ia extender which comes with a significant amount of line. This will also give you the ability to grow your power without further investment in a larger MAF (housing or pipe) or better element. The MAF.ia can be run with a setting of 0, meaning it does not alter the 5 volt signal coming from the MAF. Sounds Pretty Easy Doesn't It... That was the easy part, though It only gets easier if you forgo the remainder of the DIY thing and have an SCT tuner in your local area. So now that you have piping, electrical (in the case of a wideband and the MAF relocation if necessary), vacuum and oil feed and drain all in place what now? Here we run in to more options. Things from this point on can be a pain depending on how you set things up. If you have a stock MAF sized tube or a 3 inch pipe with the stock MAF element in it you can drive to a dyno with the stock injectors. The car will run lean if you push it in to boost, so care is a major MUST here. Don't get on it or you will break your car! You can run the car under boost all day long at any RPM, you just have to drive it like it's an egg. Any other configuration is going to need to be tuned. Whether you have the stock injectors in the car or not, the MAF transfer function is going to be off and you could run lean to the point of detonation even at idle. Option one: Drive the car, only if the conditions match the above (stock pipe, stock injectors), to your SCT or Predator tuner of choice and have the larger injectors installed there.prior to tuning. Option two: Install the injectors and have the car towed to the shop. Option three: ...and you'd better have a WB and a laptop for this because you can't do the following without it. Note: If you are a slacker like me, you may just want to get it tuned. It's tons cheaper and less of a headache. I have more reasons that one single DIY turbo for spending the money on the software and $150 an hour tuning time on the dyno. I want to know everything. It's all part of my secret plan to TAKE OVER THE UNIVERSE! ...oh crap, sorry, that was the wrong line. Break out the Xcal 2 or Livewire and your pro racer package get the strategy code via Xcal and ECU code from your cars computer (under the hood) Load up a base turbo tune - you can get this from SCT if you beg - install the 39# injector value file, if not already done by the good folks at SCT, and then start messing with the MAF transfer function. If you are running the stock intake pipe and installed 39# injectors, multiply the entire TF by 0.80. That's 80 percent of the current tune... and yes that means you are saying there is less air. The injectors you are putting in are double in side and will dump fuel like crazy if you don't change the TF.. What you are doing right now is calibrating the MAF for 39# injectors. Upload the tune into the Xcal, then into the car and fire her up. Plug in your Xcal to your laptop and open livelink. Datalog your short term fuel trims and watch your wideband. You want about 14.8 to 15.2 at idle and 14.7 at cruise. If you are doing this, then you have the PRP and should get the manual to take you the rest of the way. I can also help you get through the manual, which reads like a poorly written Math text book... and I told one of the writers that too. The rest is up to you! So take the easy way out and talk to one of the tuners on the board! I want to thank Big Studly, Race This and all the other member of the 4.0C who's curiosity lead to this write-up. |