B6 Audi A4 Big Turbo Kit Install - APR Stage 3+
Prior Experience: 7/10 - more time consuming than difficult
Cost: $5400 or cost of kit - APR Stage 3 kit shown here
Time: 12-14 hours
|Discuss this mod - Here
|NOTE: All pics are hyperlinked to higher resolution versions.
This write up is not for the common user. If you are not completely comfortable doing every other modification on this site, then I would not suggest you do this yourself. We will be modifying the ECU, fueling and the entire turbo system. An error in the installation could permanently damage your engine. If you feel that you are not very strong at DIY work, then just read this for the knowledge.
With that said, this guide is not made to be completely comprehensive. The main purpose is to show the steps needed. Since every car/kit is different, you will have to use some of your own ingenuity to figure it all out. If you start out the install, and get half way through and get stuck you could end up in more trouble than you bargained for. You should carefully inspect the current setup, and take a lot of pictures of the uninstall of the stock turbo before you proceed. It will be very easy to forget where everything goes if you don't write it down and take pictures.
SUPPLIES - At this point, you are a modifying machine - so I will assume you have all the tools you will need for this job. You MAY need to do some welding depending on your setup. I suggest you use PB Blaster or Liquid Wrench on EVERYTHING that gets hot in normal use.... it will save you lots of time. At this point, if you are considering this upgrade, I will assume you A4 is already equipped with the following at a minimum:
Front mount intercooler or dual side mount intercooler's -(RaceTec FMIC)
If you do not have these supporting mods - you are only asking for trouble. Get your car in shape before you spend the money on the turbo upgrade.
I am also going to assume you checked your car out, or brought it in for a check up to make sure it is in good running health. Any pre-existing problems will become worse with a big turbo upgrade.
As with any large installation job, be sure to be very neat with all your nuts and bolts so that you know where they go when you reassemble everything
|Parts: Unlike a lot of aftermarket turbo kits, the kit I will be installing here is a 'full' kit. By 'full' I mean it requires a new manifold, a new catalytic converter (or cat delete pipe) as well as new oil and coolant feed and return lines. This install will also need new injectors, and a new turbo inlet pipe. Depending on what you buy, you may or may not have all of these parts.
In the first part of this install you will have to get the car down to the point at which you can pull the turbo. Because there all of these steps have been outlined elsewhere on this site, I will point you to the links of where to start. Perhaps when I am not as lazy, I will add all these parts to a single write up.
With these two steps done, you will be somewhere around here
|At this point I want you to really look at what you are seeing to understand what is going on. It will be important to look around, otherwise you will get lost in the zoomed in pictures that follow.
From the air box there is a hard feed line to the Secondary Air Injection (SAI) pump which is located below your passenger's side headlight. Coming back front he SAI pump is another hard line that runs across the top of the engine.
You can see that the Turbo Inlet Pipe (TIP) has two air connections on it. One is circled above as the PCV return valve. The other is for the Diverter Valve (DV) or Blow Off Valve (BOV) and is not visible in this picture but can be seen from underneath.
From this point, you can go ahead and unbolt the CAT from the turbo. Some of the nuts are hard to reach, but you can use swivels and extensions to get at them
Also unscrew the front O2 sensor from the Cat
To pull the cat, you still have to unbolt if from the exhaust system. To do this, first unbolt the CV boot heat shield over the passenger side CV boot. There are 3 hex head bolts.
Use a hex head attachment for this - not an allen key.
The heat shield is shown here, as are two of the three bolts you need get at for the cat
The first time I took these bolts out, it was a huge pain, you can read about it in the Neuspeed Exhaust Install
After the cat is unbolted, you can take it out from the top
With the Cat out you can start to drain the coolant and oil. In some cases (where these lines are not replaced) you can get away without draining the coolant - however I decided to flush the system.
To drain the coolant, look for the Coolant Sensor on the driver's side of the vehicle down below the headlight. There is a clip holding it into place. You remove the clip and pull the sensor out. The coolant will start pouring out - so have a bucket ready
|If you are doing this, I assume you know how to drain the oil. But if not, you can check out the Oil Change write up.
The next step is to remove the stock turbo inlet pipe. You will have to disconnect the PCV valve and the hose for the diverter valve. You can get the PCV from the top, and the DV from the bottom
PCV valve has been removed here.
On the TIP you will also notice a smaller connection which goes to the N75 valve (which looks like a black "T"). This also needs to be disconnected.
With the N75, DV and PCV disconnected, you can unscrew the hose clamp that holds the Turbo Inlet Pipe (TIP) to the turbo (bottom left). With the TIP out it will look like what you see in the picture below and to the right
You should take note of the oil and coolant feed lines to the turbo. I will be replacing these, but you may not have to. In BLUE is the coolant feed, in RED is the oil feed.
Move the appropriate oil and coolant buckets under the turbo, and unbolt the turbo oil and coolant feed lines. Let everything drain
Be prepared for a mess.
Next get under the car and disconnect the oil return line
And then the coolant return line. Be prepared for more spillage.
With the oil (feed and return) and coolant (feed and return) lines disconnected, you can now pull the manifold/turbo assembly by disconnecting the manifold bolts.
You've used PB Blaster on these right? Or maybe some liquid wrench? You will notice how shiny everything is in mine... because it was covered in PB Blaster. Made life much easier.
After these bolts are out, you can pull the assembly,. and see how small it really is...hah
Installing the Turbo
Modifying the RaceTec Turbo Outlet Pipe
As mentioned previously, the turbo outlet pipe needed to be modified to work for this turbo. There are two reasons for this. First, the turbo has no connection to the N75 so one had to be added to the turbo outlet pipe to get this to work. Next, the GT28RS sits about 3 inches farther to the front of the vehicle than the stock K03 turbo. Therefore the hardpipe from the intercooler would not work as is. To modify it, I did the following
Before I went ahead and welded anything , I wanted to see if it would even be possible to get this pipe to work. In the picture to the right, you can see how far off it really was.
As it turns out, RacTec now makes their pipe as two pieces to allow more flexibility when fitting the intercooler. I contacted them and they indicated to me where they cut the pipe. I adjusted it a little bit for this application.
The first thing I did was cut the FMIC piping where the green line shows.... This was right on that second weld. This would allow me to add a flex elbow in that spot to give me the 2-3 inches of movement I required at the turbo side.
Here's what it looked like after the cut and elbow were put into place. The 2-3 inch gap was recovered.
You get another shot of my buddy Chuck that was helping me with the install.
After I knew the pipe was going to fit, I decided to weld the bung into place for the N75. I went to the local hardware store and bought a brass fitting that was barbed on one ended and threaded on the other.
I had my other friend weld a small aluminum spacer onto the pipe so that it could be drilled and tapped for the brass fitting. First I hammered an indentation of the spacer into the intercooler piping
Remember, you want to keep this connection as close the the turbo as possible!
After that was done, my buddy welded the ring in place, and it was tapped and the brass fitting was placed.
Note: welding aluminum is hard, so its not going to look pretty. However it does the job.
After that was in place, the intercooler piping could be test fit
Here's what it looked like from underneath
After the bung is welded on, you can connect the new connection to the N75, and plumb the hot side of the DV/BOV.
So now you have the turbo installed, the coolant and oil lines run, the cat bolted up, the FMIC piping modified and connected. The DV is installed, You modified the air box for the larger 3" MAF housing and can button that up. All that is left is physically installing the air box and then the injectors. Last, you can pull the ECU for it to get chipped.
If you have made it this far, I assume you will be able to re-assemble the air box and get that all together. Like I said, it is TIGHT, so you will have to have some patience fitting everything else in.
To get the injectors installed, check out the Injector Install Write up
For the ECU removal, check out the ECU Removal Write up
You should have everything you need complete. You checked all of your hose clamps so that the new turbo doesnt blow them all off right? That will be your biggest problem - just like it was for me.
Before you can turn this beast on, you have to prime the turbo. First you have to refill your oil and coolant (I am assumming you know how to do this). Then with the ECU Removed you have to crank the engine (clearly it will not start) for 10 seconds at a time for about 3 minutes. This will get all the oil through the lines and will get it primed. Keep an eye out for coolant and oil leaks. You should be good to go after that.
When you re-install the ECU, you will have to let the car idle for about 10 minutes. During this time you will see SMALL amounts of smoke coming up off the turbo. This is just oil from you hands and whatever else burning off. If it does not clear up quickly - stop and check everything!
Before you beat on your car, I suggest you follow typical procedures to break in the turbo and monitor your car closely (Air fuel ratio, etc) to make sure it is running properly. You don't want to come this far just to blow your engine.