Finer Control: Adding a James Barone Racing 3-Port Electronic Boost Control Solenoid


Not all go-fast parts are shiny and glamorous. Popping the hood at your local Cars and Coffee/cruise night/car show and having the crowd gawk at your new big turbo or ooh and ahh at that 3″ intake is a feel good moment. A kind of validation that all of the long nights in the garage, the depleted bank account and the ramen diet were all worth it. But a lot of the time it is the unseen, dull, boring looking parts that are the key to making everything work, like how The Dude’s rug really brought the room together.

On most people’s list of big power go-fast items, a boost control solenoid is probably not in the top five. Or ten. Maybe top 15, but low on the list. Most people probably don’t even know what a boost control solenoid does other than its title, and probably have no clue about how the solenoid does it job can affect the engine in different ways. Fortunately for you, you are not like those people because you are here on Five Five Garage and you know that I am about to drop some hot knowledge and you have your notebook ready.

When I was researching boost control solenoids for this article I found so much information about it, that it will be too much for me to do really dig into for this piece. But, don’t worry! I am going to write a Start-Up series article that goes more in-depth on the topic. For this one I am going to explain some points, explain why I added one to my project, and show some installation pictures! On with the show!

Electronic Boost Control Solenoid Basics
A stock and aftermarket EBCS
Left: OEM 2-Port EBCS. Right: JBR 3-Port EBCS

A boost control solenoid does exactly what it sounds like, it controls boost. How it does so can be simply described as a binary device, like a light switch. It is either on or off. You press on the gas and the ECU sends a signal to the EBCS to stop boost pressure from reaching the wastegate actuator, which closes it, and the turbo begins building boost until the target boost value is reached. Without it, once boost pressure raises to the level to overcome the wastegate spring pressure (which I think is 8 lbs.) then the wastegate opens and the turbo will no longer build boost (which is a beneficial thing, if your EBCS fails, the wastegate spring will open and prevent the car from overboosting).

Why I am changing it and why you should too
OEM 2-Port Electronic Boost Control Solenoid. Stock configuration uses the “bleed” type setup.

The EBCS controls boost pressure by opening and closing very fast, many times a second. Mazda engineers did a very good job designing the EBCS that comes on the car, and it does a good job handling the stock boost level. Where the issues begin is when you decide to increase boost pressure beyond stock levels. The OEM configuration uses what is known as a “bleed” type setup (I will cover the different types of EBCS setups when I do the Start-Up article), which has a slow response time. The OEM system is tuned to operate at the stock boost level (15 lbs.) and once you start adding parts (accessport, intake, and exhaust) the OEM EBCS can be maxed out to a 100% duty cycle and still NOT be able to provide the desired boost pressure. If the EBCS can’t keep up, it can result in problems such as the wastegate opening prematurely, which at high boost levels will cause your tune to not hit boost targets and at low boost levels causing very low turbo spool-up.

If you are planning on tuning your car past the stock boost level, an upgraded EBCS should be considered mandatory. There are multiple manufacturers of EBCS to choose from. Cobb, Corksport, and Grimmspeed all make an updated EBCS, the one I am using I ordered from James Barone Racing. The JBR kit comes with everything you need to install it and you can also find instructions with pictures on the JBR site. Since I had the car apart already installing my front mount intercooler, I decided to throw on the EBCS.

James Barone Racing Electronic Boost Control Solenoid
The James Barone Racing Electronic Boost Control Solenoid $79.50

Installation of the new EBCS is pretty straightforward. I recommend removing your battery/battery case as it will be in way. You need to remove the OEM EBCS from the turbo with a 10mm socket. Also have some needle nose pliers handy, because you need to remove the vacuum line from the wastegate actuator and your intake. I left the old vacuum lines connected to the OEM EBCS, the JBR kit comes with new hose, so no sense in re-using the old stuff, you also reduce your chance of a boost leak using the new hose. The JBR EBCS does require a bit of construction before you can use install it.

JBR EBCS and Thread Sealant
When you install those fittings, use some thread sealant on the threads, to reduce chance of a boost leak.

The JBR (and mostly all of the aftermarket units) EBCS can be set up in either a 2-port or 3-port configuration. The 2-port configuration does not require a tune. So if you are future proofing, you can set it up in 2-port (bleed mode, just like the factory configuration), install it on the car, and go about your day. 3-PORT CONFIGURATION WILL REQUIRE A TUNE. If you set up a 3-port configuration and you are not tuned for it, you can cause some very problematic issues, such as overboosting, which is a bunch of bad engine juju. Whatever configuration you decide to use, I recommend using some thread sealer on the threads to ensure you won’t get air leaking past the threads.

JBR supplied mounting bracket installed onto the back of the EBCS
JBR even includes a mounting bracket.

JBR includes a mounting bracket and hardware, have some blue thread locker on hand to make sure those nuts wont back off once they are tightened down.

JBR EBCS Construction Finished
When construction is complete, you end up with something that looks like this.

Once everything is secure, it is time to install the setup onto the turbo. You have a couple choices on where you can mount it. I have see some people mount it on the front of the battery box, I have seen them mounted onto the firewall, I decided to mount mine back onto the turbo for convenience.

JBR EBCS on K04 turbo
The JBR EBCS installed onto the K04 turbo. To the right, you can see the wastegate actuator.

You are going to need an 8mm to loosen the bolt that is holding the upper coolant hard line on the turbo, this where you can mount the EBCS bracket. Now would be a perfect time figure out the length of the new hose you need to connect the wastegate actuator to the EBCS port. Connect the new EBCS plug to the EBCS wiring harness, make sure you click it in properly.

EBCS with wastegate actuator hose connected
New wastegate actuator hose connected.

Install the new hose, I used zip ties to help ensure the new line doesn’t blow off. I also grabbed some black wire loom as the new EBCS wires are long and the hot side of the turbo is so close, I decided to protect those wires as best as I could from the heat and any possibility of those wires coming into contact with the turbo.

EBCS to TIP connection
The last connection is made to TIP (turbo inlet pipe).

After you have the wastegate actuator line finished, the last hose connection that needs to be made is to the TIP (turbo inlet pipe). Once that is complete the install is done. If you are in 2-port configuration you can start the car and enjoy better boost management. if you are in 3-port configuration, contact your tuner for a revision.

I am looking forward to tracking the improvement this makes to my car. I have noticed for awhile that I am unable to consistently hit the same psi while I am out driving. I will make sure to keep you all updated on the progress!

Get out there and drive,



James Barone Racing 3-Port Electronic Boost Control Solenoid