This task is not for those who are not mechanically inclined. The process is relatively straightforward, but can be a pain at times. It will take longer than you think. This guide is designed for non cruise-control equipped engines.
To make sure you don't get a pressurized splash of fuel when removing the fuel rail and injectors from the engine, pull the Fuel Pump relay from the under hood fuse box. Attempt to start the vehicle. If it runs, let it die. Crank the engine over for 3 seconds when it won't start. The fuel rail should now have no pressure.
The fuel rail is held in by two bolts that go into the head. Disconnect the wiring harnesses going to the camshaft tower and each fuel injector. Disconnect the vacuum hose that runs to the fuel pressure regulator. To remove the injector connections from the injectors, use needle nose pliers to grab the light blue piece and pull it up from the injector. It will move out about 1/2" and stop. Now you will be able to depress the black tab on the center of the injector wire connector and pull the connector upwards and off the injector. Do this for all four.
Remove the two bolts that hold the fuel rail in. The fuel rail should now be able to pull up and off the cylinder head. Try to hold all of the injectors in the rail when pulling the assembly out of the head in order to avoid any unplanned fuel spillage.
Disconnect all intake piping and couplers from your air intake. Unplug the two sensors on the throttle body, and disconnect the vacuum hoses from the throttle body.
Pry up the two plastic pushpins that hold the throttle cable cover down to the throttle cable bracket. Remove the cover to gain access to the throttle cable assembly. Rotate the throttle to wide-open and slide out the throttle cable's end through the hole. Now the cable is disconnected from the throttle body and can be moved aside.
Unbolt the throttle body from the intake manifold by removing the four 10mm bolts. Remove the throttle cable cover and the throttle body and set aside.
We must take a break from fuel system modification and do what needs to be done with the intake manifold, since the fuel rail normally would be somewhat in the way of unbolting the manifold.
Unplug the MAP sensor's electrical connection (only sensor on the intake manifold). Unbolt the 7 bolts (5 top, 2 bottom) holding the intake manifold to the head. Remove the manifold and set aside.
Place the new flat intake manifold gasket (that blocks off the small hole between ports 2 and 3) between the intake manifold and the cylinder head. Line it up, and thread in the bolts. Tighten the intake manifold to the head.
Be sure to have a few absorbent towels underneath the fuel rail when removing the injectors. There will be fuel. The injectors just pull out.
Slide a coating of clean engine oil on the o-rings before pushing the injectors into the fuel rail. This will help seal them and allow you to get them in without distorting the o-ring.
Coat the o-rings with clean engine oil. Push the fuel rail into place by aligning the injectors with the holes in the cylinder head and pressing the rail so they fit into the holes. Install the two fuel rail bolts you removed. You may now connect the wiring harness to the injectors and the camshaft position sensor.
To install the new MAP sensor, remove the vacuum hose that runs from the center front of the intake manifold to the MAP sensor, and simply slide the old sensor off of where it mounts on the intake manifold, and put the new one on and connect it with some new vacuum hose. Reconnect the MAP sensor's electrical connection.
Bolt the throttle body back down to the intake manifold by reinstalling the four bolts. Be sure to place the throttle cable bracket in between the bolts and the throttle body.
Reconnect the electrical connections to the TPS and IAC on the throttle body. Leave all vacuum lines disconnected for now.
The hard metal brake booster hose gets in the way of things. Disconnect the rubber hose behind the engine that runs to it (and where it connects to the brake booster), and remove the hardware (nuts/bolts) that hold it to the engine. Remove the brake booster hose. You may have to bend it quite a bit to remove it, but it is not important, as it will be replaced.
Once you work the metal hose out of the engine bay, discard it. Cut the 5/8" high pressure hose to size and connect it to the throttle body's large barb fitting and to the brake booster's barb fitting using hose clamps. This allows it to run alongside the engine all the way instead of coming up behind the engine and getting in the way of the turbocharger.
(New brake booster hose, center, clamped to the bottom of the brake booster assembly)
Drain the oil and coolant. Open the oil and coolant caps. Then unscrew the oil pan drain bolt and collect the oil that drains out. Remove the oil filter and collect the oil that drains from that. To drain the coolant, it gets messier. Pull off the metal hose that runs under the oil pan and is clamped on by a rubber hose. A significant amount of fluid will drain from this location. The rest will pour out during another step.
The stock coolant bleed hose is a metal tube that runs from the driver's side of the engine (coming out of the large plastic coolant outlet) and runs behind the engine. A rubber hose connects from that metal hose to the coolant overflow reservoir. This coolant line will get in the way of the turbocharger, so we must route it in front of the engine instead.
Cut the metal line just past the bracket that holds it in place next to the plastic water outlet. Leave enough room to slide a 1/4" fuel hose over the end. Discard the rubber and metal stock hoses.
Connect a 1/4" ID fuel hose to the cut section, clamp it. Route the hose to the coolant reservoir in the same spot you disconnected the old hose, but this time have the hose routed over the intake manifold instead of behind the engine like the stock metal one was. Clamp everything tight.
Remove the one nut that holds the dipstick bracket in place (rear of engine, on the camshaft cover). Pull the dipstick up and out of the engine block.
Use an electric saw to cut the downpipe just before it makes the bend to horizontal piping, or as far back as you have new exhaust pipe to fit.
Unplug and unscrew the stock upstream oxygen sensor that is in the exhaust manifold and save for later.
Remove the bolts that hold the heat shield in place, discard both. Remove the nuts on each stud that hold the exhaust manifold in place against the cylinder head. Then slide off the exhaust manifold. Discard.
In order to use an oil drain line, the oil pan must be modified to accept an AN braided hose fitting. Mark a spot (as high as possible) on the rear of the oil pan, to the right of the black metal coolant hose that runs down behind the oil pan and under it. Leave enough room to weld on all sides of the fitting you intend to put into the hole.
The metal hose you disconnected from the rubber under the oil pan and drained part of the coolant from must be removed in order to be able to remove the oil pan. It elbows and runs up to the water pump area behind the engine. There are two bolts or nuts you can access from the top with a socket extension. Unscrew and remove them, and then pull the metal line from the bottom off and out of the engine bay. There will likely be a significant amount of coolant that will drain out. Prepare for a shower. I suggest a parka and goggles.
Drill a hole where you marked so that there is enough room for the 1/2" NPT x -10AN 90 degree fitting to fit beside the coolant line and enough room for you to thread on a braided hose and AN fitting to it. If the fitting is anodized, be sure to grind off all of the coating on the threads before welding.
Clean the oil pan completely so that welding will not be hazardous and will not be poorly done with a dirty surface.
Insert the 90 degree fitting's thread side into the oil pan hole you just drilled, leaving it sticking out far enough so that you can twist on an AN fitting to the -10AN side of the 90 degree fitting once the oil pan is reinstalled.
Place the oil pan back onto the engine block, being sure to line up the gasket. Reinstall all of the bolts you removed and tighten securely.
You may now reinstall the metal coolant hose elbow using the two bolts or nuts that you removed from it. Reconnect the metal hose to the rubber one under the oil pan using a new hose clamp instead of the stock rusted squeeze clamps.
If you are using an external wastegate, bolt it to the bottom of the manifold with the supplied hardware and use a wastegate gasket.
If you are using an external wastegate, you must either route a pipe straight down, or route it to the downpipe (difficult). For now, just dump it straight down using a pipe and flange angled similarly to the one in the image.
Later, one can add piping to splice the dump tube into the rest of the exhaust system at any local exhaust shop with ease.
Secure the oil feed flange to the top of the turbochargers CHRA in the same way. Be sure that the oil feed line or flange has a restrictor built into it (very small orifice, not a hole the size of the hose).
Do not connect any oil feed or drain AN fittings or braided lines yet.
Once the housings are rotated the way they need to be, and your oil feed and drain connections are accounted for, place the turbocharger onto the manifold and secure it with four bolts and lock washers, being sure to use a gasket between the turbo and the manifold to prevent leaks.
The turbocharger can be seated with the turbine side on either the driver or passenger side of the manifold mounting point, depending on how you rotate it. For ease of downpipe fabrication, having the turbine side on the passenger side is suggested.
Remove the stock oil pressure sensor by disconnecting the electrical connection (cable tie it out of the way somewhere if desired, it's going to stay disconnected forever), and then unscrewing it from its position in between the camshaft towers.
Thread the 1/4" NPT adapter into the camshaft tower using teflon tape, and then thread in the oil feed line into the adapter, also using teflon tape. Tighten.
Connect the oil feed line to the turbocharger oil feed flange on the top of the CHRA. No tape necessary, the connection seals via the flare angle.
Install a straight AN fitting to one end of your braided stainless steel hose, and thread the fitting onto the turbocharger's oil drain flange on the bottom of the CHRA.
Route the hose down to where the fitting is in the oil pan. You're going to be using the 45 degree fitting on the oil pan fitting, not a straight AN fitting. Observe the length of the braided hose. Remove the fitting from the CHRA in order to cut the hose to length. Leave enough wiggle room so you don't cut it too short.
Fit the 45 degree AN swivel fitting onto the just cut end of the braided hose, and then install the hose to the CHRA and the oil pan 90 degree welded fitting.
The front bumper, if stock, is typically attached with 3 bolts on either side under the fender, two pushpins under the hood at the front top center of the bumper, and various other plastic pushpins along the bottom and fenderwell (the plastic liners need to be disconnected from the bumper.
The bumper support is held on by two U bolts on either side of the support. You can remove these by unscrewing the nuts on each and hammering the main plastic bumper support piece away from the actual metal support. This gives us enough room to mount the intercooler.
You may use self-tapping screws to attach the brackets to the metal front bumper support once centered and aligned where you want it. Put a bolt through each bracket and thread it into the top of the intercooler core's threaded bungs to attach.
If you have a BOV pipe adapter, which is a short section of pipe with a blow off valve flange welded to it already, simply insert one end into the 90 degree silicone coupler off the throttle body and clamp it down at an angle that will clear the hood. If you have a BOV flange, piece together a charge pipe to fit over the battery and bend down into the fenderwell where the stock plastic intake system used to be. Cut a hole in the pipe where the BOV is to be mounted, and weld the flange to the pipe.
Install the BOV using the supplied gasket and bolts.
Connect the PCV hose (that has the check valve in it coming from the PCV baffle under the intake manifold) to the throttle body at a small port.
Connect the HVAC hose (gray plastic with rubber elbow) and the EVAP canister hose (comes from the bottom left of engine bay near the serpentine belt) to a two way check valve, ideally, and the check valve to the larger port on the throttle body.
The fuel pressure regulator (FPR) hose can be connected to the other open small port on the throttle body. You can splice your boost gauge hose into this hose using a plastic T fitting.
The intercooler/charge piping runs from the turbocharger to the intercooler to the throttle body.
Using mandrel bent aluminum piping, cut sections to size to route the piping as such. Connect your 90 degree silicone coupler to the turbocharger that adapts the turbo outlet to the charge piping size (commonly 2" to 2.5"). Piece together the aluminum piping, weld as many connections as feasible, and use high quality 4-ply silicone couplers and t-bolt clamps on those you are unable to weld.
Weld the aluminum 3/8" bung into the charge pipes as close as possible to the throttle body, and thread in the new IAT sensor and connect it electrically.
An example of pipe routing:
Once your charge pipes are installed and tightened, you can reinstall your front bumper.
Fill up your coolant with 50/50 of your coolant mixture (most commonly dex-cool and distilled water). Add a bottle of Water Wetter if you want extra cooling capacity.
Fill the engine with oil, 4.5 quarts is ideal. 10W-30 has worked well for me, however there are better options, such as full synthetic. Many run 20W-50 synthetic on turbocharged engines. Use whatever you think is best.
Flash a basline tune using HPTuners (the GM Supercharger Kit reflash works well) with the injector constant corrected for the size injectors you're using, and with closed loop operation turned off (so the car doesn't try to correct itself, that's what you're tuning for).
Head out and tune. Basic tuning will be covered in another How-To.