DIY Stage 2+ (Downpipe, Uppipe, TMIC, EBCS, Ram Intake, Wastegate Blockoff, EWG)

[FMS]

Hi All,

I am here today to offer a simple How-To instructional to do a basic Stage 2 Mod to your WRX/STi. I have included support mods in the install and though they are not always needed, they serve a great purpose.

What is going to be gone over in this How-To:

• Downpipe
• Ram Air Intake
• 3 Port Electronic Boost Control
• Uppipe
• Wastegate Block-Off Bracket
• External Wastegate
• Top Mount Intercooler

Tools Needed:

1. 8mm Wrench/Socket
2. 10mm Wrench/Socket
3. 12mm Wrench/Socket
4. 14mm Wrench/Socket
5. 22mm Wrench/Socket
6. Needle Nose Pliers
7. Wire Cutter (for vacuum line)

The installs gone over in this How-To are very simple that if carefully done anyone with a wrench could do.

Start



1. Always start by disconnecting the negative on the terminal on the battery.
2. When working with the downpipe and heat shield I find it easier to remove the TMIC. The following steps show you how to remove your OEM WRX TMIC 08+


Removing your OEM TMIC

1. Disconnect your BPV. 2x10mm Bolts (rubber gasket stays in/on the BPV)
2. Un-bolt the support bracket above the BPV.
3. OPTIONAL Loosen but do not remove the support bracket for easier re-install.



4. Disconnect your Intercooler from your Turbo (passenger side of vehicle). 2X12mm Bolts (rubber gasket stays in/on the Intercooler)



5. Go back to your drivers side now and loosen the clamp around your Intercooler to Throttle Body inlet hose.



6. Once this is done the intercooler will be free and you can easily remove the intercooler. I always use blue painters tape to seal all open ports to the motor/turbo just in case something falls in. You don't want to be taking apart the motor for a single nut.



Your going to leave the intercooler off till everything else has been completed on the car.

Next: Heat Shield and Downpipe

[FMS]

Heat Shield

1. Remove the 3 x 10mm bolts. (aftermarket heat shield)





2. With the intercooler off you can lift the heat shield upwards, with the intercooler on you can attempt to slide it down the pipe and remove it later with the downpipe.



Downpipe

1. Once your heat shield is off you will find 2 x 14mm Bolts, 3 studs threaded into the turbo exhaust and 5 x 14 mm nuts. 5 total fasteners. Remove the nuts off the 3 studs but leave the studs in the turbo. Remove both the bolts and nuts from the top of the turbo.





2. Now follow the downpipe down near your transmission. On the far side of the downpipe is 1 x 14mm bolt threaded into the transmission case. Remove this.



3. Finally follow your downpipe from under the car and find the support bracket with 1 x 14mm bolt and lock washer in it. Remove the bolt. Once the bolt is removed follow the downpipe back to the mid pipe and free the 2 bolts connecting the downpipe to the rest of the cat back exhaust. Go back to the support bracket and un-hook it by using a flat head screw driver.

4. Un-snap your O2 sensor in your stock downpipe and route it back across the transmission cross member and back out the heat shield under the car.



5. Your downpipe is now free! You now will swap the O2 sensor into the new downpipe. If you have an uppipe to install, hold off on re-installing your downpipe and move on to your uppipe swap. If you are not installing an aftermarket uppipe, you man now install your aftermarket downpipe using a new gasket and follow these instructions in reverse order. Congrats on installing your new downpipe!



Next: Wastegate Block Off, Uppipe, External Wastegate

[FMS]

Internal Wastegate Block Off, Uppipe, External Wastegate

**This next couple mods are not going to be for everyone. So if you aren't upgrading to an external wastegate then disregard the following instructions.**
**Running an external wastegate will require a pro-tune or open source pro tune.**

First and foremost an internal/external wastegate(EWG) opens to control boost levels by not allowing all the exhaust gasses to spool the turbo. An EWG is larger than the internal wastegate and allows better boost control. External wastegates are before the turbo on the uppipe (requires special uppipe) and diverts exhaust gases out and away from spooling the turbos turbine. When open, the external wastegate dumps some of the exhaust gases into the atmosphere, but EWG are very loud when dumped into the atmosphere. If noise is not something you wish to have yet your having troubles controlling boost levels, then instead of running a dump tube back into the atmosphere you can run the tube back into your exhaust system after the turbo.

**Note: If you run a 3" downpipe with a 3" cat back exhaust you may run into overboost problems even with tuning. In this case, an external wastegate may be the answer.

**NOTE: You should set your bar up with a spring setup allowing wiggle room. Below your desired boost levels, yet above the base boost levels your car can obtain. This way it will still allow some boost fluctuations depending on weather.**

In the following steps I am going to show you how to prep your turbo for the new wastegate and install your new wastegate.


Internal Wastegate Bracket

With any external wastegate set up your going to want to block off the internal wastegate. First though you need to locate it and understand how it works.

This is your internal wastegate:



To block off your internal wastegate you must either weld it shut, which is almost irreversible, or use a bracket to block it off. Grimmspeed makes an extremely nice bracket. Here is the easiest way to install this bracket.

Here is your stock wastegate actuator. Your wastegate actuator opens when your boost controller feeds boost to the vacuum line attached to it which pushes on a spring/diaphragm and arm.



Here is a video showing how the stock actuator works:
Turbo wastegate actuator test - YouTube

1. You start by removing your stock actuator.To do this you must remove 2 x 8mm bolts that are threaded into the back of the compressor cover of your turbo. Then follow the actuator arm back to the internal wastegate control and remove the C-clip on the underneath to free the arm.
2. While you have the wrench in hand you should verify which bolts your block off bracket will need you to remove to install it. Some brackets require more bolts than what hold OEM actuator. In this situation the VF52 bracket requires one extra bolt.



3. Once the bolts are removed you will need to remove the vacuum line. Set your actuator aside and save it for later in case you go stock again.



4. Bring in your new block off bracket and finger tighten the rear bracket to the internal wastegate control.
5. Finger tighten the same 8mm bolt you removed earlier. Do this for all 8mm bolts removed.
6. Tighten 3 turns.
7. Tighten 3 turns.
8. Tighten 3 times and go back to instruction #6.
9. Tight all three bolts till snug with the back of the compressor cover.



10. Finally tighten, TIGHTEN! the rear bolt. (refer back to step #4)

Your block off bracket is installed!

[FMS]

Uppipe

Uppipes can be replaced with aftermarket oem replacements or aftermarket replacements that allow the addition of an EWG. In this how to I will be using one that allows for an EWG to be installed however let it be noted that the install is the same.

1. Locate your exhaust manifold under the from of the motor and on the passenger side unplug your front O2 sensor. Follow the yellow wire to the heads and locate the plug.
2. Remove the heat shields from both sides of the manifold. (4 Bolts on passenger side, 3 bolts on drivers side) (Be sure to reconnect the ground wire after reinstall.)



3. Remove the 2 x 14mm bolts from the manifold to the uppipe.



4. Next, drop the manifold be removing 3 x 14mm nuts from both sides of the manifold.

[FMS]

5. Remove the 5 x 14mm nuts holding the Uppipe to the turbo.



**NOTE: The dowpipe must be off to remove back 2 bolts.**



6. Go back under the car and remove the 14mm nut and washer from the passenger side motor mount. (In the picture the nut is already removed.)



7. DON'T FORGET NEW GASKETS

8. Since the OEM Uppipe is covered by a heat shield it can be very hard to remove without raising the engine. Use a safe method for lifting the engine on the passenger side. The motor only needs to be raised 1" to be able to remove the old uppipe. Since I am using an uppipe with an EWG my aftermarket one is just as bulky as OEM and requires me reinstalling it while the engine is still raised up. Feed the new uppipe with the studs already installed back into place and finger tighten the nuts on the turbo end. Lower the motor and start reinstalling the exhaust manifold. Makes sure as to not torque anything down until all bolts and nuts that were removed in steps #3,#4,#5,#6 are reinstalled loosely. With everything loosely hanging and loosely bolted together (mocked up), tighten everything down.

9. Reinstall all heat shields and plug your front O2 sensor back in.

Your new uppipe is in! (Remember ours has a 38mm port for an EWG.)

[FMS]

External Wastegate



Start by understanding your EWG


1. Take your external wastegate and make sure to use the most convenient location for the air port. Not all applications will require all water fittings and all air fittings and if it is not required, seal these ports off with the plugs provided. Take your wastegate now and mate it up to the uppipe and use to largest V-band clamp to secure it with 1 x 8mm bolt and lock nut. Make sure that the valve seat does not fall out of the valve housing(shown below).



2. Once the wastegate is mated up to the uppipe, secure the dump tube. Some larger downpipes and catted downpipes require modification to the dump tube. I myself welded in a 1.5" section of tubing to clear the catalytic converter. Secure the dump tube with the smaller V-band clamp and 1 x 8mm bolt and lock nut. Run the vacuum line up to the top of the motor but keep it away from anything hot. Heat wrap the vacuum line if necessary.



Your External Wastegate is installed!

If you have been waiting to reinstall your new aftermarket downpipe you may do so now.

[FMS]

Electronic 3-Port Boost Control Solenoid

Your 3-Port Boost Control solenoid takes pressure/boost from your turbo's compressor and feeds it to the wastegate to open it. The OEM one is good but the Grimmspeed 3 Port is even better. In the following steps I will show you how to install one of these units.

1. Remove your stock boost controller. Do this by removing 1 x 10mm bolt, 1 electronic plug, the "T" vacuum line that runs under the manifold and back to your stock wastegate actuator and turbo compressor cover nipple. Finally remove the air line that goes from the back of your OEM boost control to your turbo inlet hose.



The "T" Vacuum line is behind the intake manifold and in front of your turbo. Remove this carefully.



2. Mount your EBCS. I did not like the location Grimmspeed wanted me to mount the EBCS so I made a custom bracket to hold it. This bracket keeps it out of the way of the pulley cover and maintains a good clean look. Every car will have different mounting locations. (You may need to remove the other sensor temporally depending on your mount. Replace once your EBCS is mounted.)



3. Plug your electronic plug back into the OEM main wiring harness.
4. Go back to your OEM solenoid and remove the largest "U" shaped hose and take the sizing connector found in the "T" and remove this too. With the large "U" shaped hose in hand and the sizing connector in the other hand insert the large end of the sizing connector into the large hose. Run the other end of the large "U" shaped hose back to the original turbo inlet hose location. Go back to the sizing connector and run this back to port 1 using 5/32 vacuum line.
5. Cut a longer piece of 5/32 vacuum line and run it from port 2 under the manifold and back to your wastegate actuator or external wastegate. (Whichever you have.)
6. Cut about the same length 5/32 vacuum line and run it from port 3 under the manifold and back to your turbo compressor cover nipple.



PORT 2

Can go to either:



OR



Port 3



**NOTE: you will no longer have a "T". You will run separate lines.

For more info here is a video of the install:
GrimmSpeed Boost Control Solenoid Install 08+ WRX/LGT - YouTube

Your electronic boost controller is installed!

[FMS]

Cobb Ram Air Intake and Top Mount Intercooler

Cobb Ram Air Intake

1. Remove stock box and MAF hose. First remove your stock air scoop and unplug the electronic MAF plug.
2. Remove the 10mm nut at the front of your air box on your passenger side.



3. Remove the 10mm bolt at the base of your air box on the drivers side of your air box.



4. Unscrew the worm drive hose clamp from your turbo inlet hose and remove the MAF hose from the turbo inlet hose.



5. Un-snap the back half of the air box and lift it straight up.



6. You can now lean the front half of the air box back and lift it straight out too.



Prep the new Cobb SF Intake by assembling everything except the support bracket. (Swap MAF sensor from OEM to new)

[FMS]

Installing the new Cobb SF intake is very...very...simple.

1. Install the mount bracket using the 10mm bolt from the base of the OEM box.



2. Install the new Cobb cone filter, MAF hose provided, and plastic connector as a whole on to the turbo inlet hose tightening both worm driven clamps.
3. Tighten 2 x 10mm bolts and lock washers to the plastic connector and metal bracket provided from Cobb.
4. Plug the MAF sensor back in.

Your Cobb SF Intake is installed!

Top Mount Intercooler

To install an aftermarket TMIC you may need to replace the turbo compressor cover to intercooler gasket. However other than that, a direct bolt on TMIC will go on the same way the OEM one came off. Refer back to the removal of the OEM intercooler at the beginning of this how-to.

Remember to keep everything loose until the TMIC is mocked in. Feel free to tighten everything snug once this is done though.

Summary

Finally: Reconnect your batteries negative terminal.

Your pretty much done! Don't go out and test the new power though until you have had a pro-tune done. Whenever a EBCS or EWG is involved you must always... get a tune!

I will be posting some troubleshooting on common problems that arise when switching to stage 2 later.

I hope this was very helpful and feel free to PM me with any questions.

Cheers!

[Scnsaracer]

Nice write up thanks for taking the time.

[FMS]

Nice write up thanks for taking the time.

Thank you sir.

[Trenda22]

Does the car need to be tuned after installing a new up pipe and intake? and can one instal a new boost control without the new wastegate or do they need to be done together? I am just wondering if this all has to be upgraded together or if it can be done one piece at a time. Just thinking about the wallet. :0)
Thanks for such a great How To!

[FMS]

Thank you!

A tune comes highly recommended. You can install the 3 Port Boost Control with the stock wastegate actuator. You can then add the wastegate later. External wastegates are not always needed. Only when a large turbo is in place or you have a very finicky car that has a hard time controlling boost levels.

[Heide264]

A tune comes highly recommended. You can install the 3 Port Boost Control with the stock wastegate actuator. You can then add the wastegate later. External wastegates are not always needed. Only when a large turbo is in place or you have a very finicky car that has a hard time controlling boost levels.

Nice write up!

I'd add that using a catless down pipe or having a 3" exhaust all the way back can cause difficulties controlling boost. I went EWG after trying to tune my catless stage 2 STi due to having both bad boost spikes and boost creep. Adding an EWG made boost control as easy as pie.

[Trenda22]

Thats good to know. I will probably do the up pipe, down pipe and exhaust all together before I get it tuned. Maybe even the boost control. I really like the low deep sounding exhaust but not so loud that I sound like a 19 year old. lol. Do you have any suggestions? I have found stuff that is low priced to stuff way outside what I would want to spend. Whats your opinion? Thanks.

Nice write up!

I'd add that using a catless down pipe or having a 3" exhaust all the way back can cause difficulties controlling boost. I went EWG after trying to tune my catless stage 2 STi due to having both bad boost spikes and boost creep. Adding an EWG made boost control as easy as pie.