Manual Boost Controller Installation Procedure for a EVO VIII or IV:

I recently installed a MBC in my EVO. I searched for and read most of the threads on this topic. This is nothing
new, but it is organized in a different way to make it easy to follow IMO. I borrowed some of the pictures from
other threads and put together some new ones.

Dan (drb)


Installing From Under the Car (This is the easiest method in my opinion):

• Raise the front of the car with ramps or jack stands.

• Remove the under tray/under panel.

Installing From Above the Car – From the Engine Bay (This requires removing & reinstalling the following):

• Remove the stock snorkel.

• Undo the four clamps that hold the stock intake box lid on.

• Remove the intake box lid and the air filter.

• Take the intake box out by removing the 2 bolts (10mm) on the bottom of the intake box & unplugging
the electrical connection to the MAS.

• Loosen the hose clamp that holds the stock intake box to the turbo intake pipe or MAS.

• Remove the turbo intake pipe by loosening the hose clamp at the turbo.

• Remove the upper intercooler pipe.

Steps:

1. Remove the stock hose from the wastegate actuator nipple.

2. Remove the stock hose from the turbocharger nipple. Note: The turbo and wastegate actuator are located
near the radiator under the exhaust manifold.

3. Remove the stock hose from the intake pipe nipple.

4. Remove the stock hose’s from the two nipples on the boost control solenoid.

5. Save the stock hoses with the boost restrictor pills built in them in case you want to reinstall them in the future.

6. Mount your MBC in a convenient location.

7. Cap the intake pipe nipple.

8. Cap the two boost control solenoid nipples or cut a short piece of new hose and loop it between the two
nipples. You can also just leave these two nipples open if you want to.

9. Install a new hose from the manual boost controller “outlet” nipple to the wastegate actuator nipple.

Boost Reference Source:

There are two popular choices for the boost reference source for a MBC. There are pro’s and cons to either method.

Option #1: Compressor/Turbo housing discharge nipple

Option #2: "T" into the hose that runs between the diverter valve (DV) & the intake manifold. Note that the
DV is often referred to as a BOV.

10. Chose Option #1 or Option #2 from above for your boost reference source. Note: There are other options
these are just the most common options.

For Option #1:

• Install a new hose from the manual boost controller inlet nipple to the turbo housing discharge nipple.

For Option #2:

• Install a barbed T-Fitting in the stock hose running between the BOV and intake manifold.

• Install a new hose from the manual boost controller inlet nipple to the T-Fitting that you installed in the hose running
between the BOV and intake manifold.

• Cap the turbo nipple.

11. Secure all the hoses and the caps with zip ties.

12. Reset your ECU by disconnecting the battery (negative cable) for a few minutes.

13. Turn the boost controller all the way down and then drive your car to check your boost in 3rd and 4th gears.
Stop and adjust the MBC. Repeat this process until the boost is where you want it.

 

more pics

 

looks very nice.

 

good write up, seems like you spent some time and effort to compile this information.

 

there's a thread Evo how to/installation, nice write up and where did you get that intake cover, looks nice

 

I made the induction box from aluminum sheet and bar stock. It was a real PITA to get it to fit just right, but I wanted a box made of aluminum that utilized the stock air snorkle, and I couldn't find anyone that made them.

Dan (drb)

 

This is partially wrong and misleading! Yes, the compressor housing's discharge nipple can be used as a boost reference source. However, the nipple on the top of the WGA is not to be used as a boost reference source.

Instead, the second or alternative boost reference source is to "T" into the line which runs between the intake manifold and the diverter valve.

So, the 2 options for boost reference sources are:


1) "T" into the DV/intake manifold line

2) Compressor housing discharge nipple

 

Since the MBC has two ports(nipples) you should distinguish between them:

1) The bottom port(the port diametrically opposed to the adjustment knob) on the MBC is the boost reference port. This (reference) port is the one which must be routed to the boost reference source(compressor nipple, or, IM/DV "T").

2) The other, or side port on the MBC, should be routed to the nipple on the WGA.

EDIT: BTW, impeccable fab work on the heat shield! I'd like to buy one.

 

sparky - thanks for the comments. I agree that my wording could have been better - I made some corrections/revisions to my original post. I just referred to the MBC nipples as inlet and outlet so that it covers all MBC's including inline designs. If you see anything else that doesn't look right please let me know.

Thanks for the compliment on the heat shield/induction box. If I charged by the hour you would change your mind about wanting to buy one!


Dan (drb)

 

Did you weld it together and what type of sheet metal did you use? Im totally going to make my own to protect my cone filter.

 

No I didn’t weld anything, although that would be a good way to do it. I used aluminum rivets to hold it together. I used .040” 6061-T6 aluminum sheet for the box, with lot’s of sanding, buffing, and polishing for the finished look. I riveted some aluminum rectangle bar stock to the aluminum sheet and then I drilled & tapped the holes for the bolts that hold the cover on.

Use cardboard/posterboard to make a template because you will probably end up making several versions and it’s much less expensive and easier to work with than aluminum sheet. Good luck!


Dan (drb)

 

Great writeup...I really like where you mounted the MBC!

 

I added a link to this thread in the current mbc install in the how to section

and gave you credit for it of course

 

sweet cover looks awsome

 

followed all the instructions and my mbc adjusted to 21 psi tapers to 19, and when i crank up the boost only a 1/4 turn it goes to 21 psi and creeps to 30 psi..could it be the mbc is faulty...please help!!!! I ran a new line from the mbc to the wastegate and used the stock vaccum lines from the turbo to the other end of the mbc....I felt the vaccum line and theres no resrtictor pills in it.....