Mazdaspeed/MPS Optimal Upgrade Path


Every vehicle in the COBB lineup is designed for the enthusiast from the factory.  With that in mind, it’s no surprise there are tons of different aftermarket options for every COBB supported vehicle.  As one of the first mainstream direct injected turbo cars, the Mazdaspeed platform gets a lot of aftermarket love.  There are so many parts available!  So many options make it common to see certain power adders installed that lack necessary supporting modifications.  Ahead will be the sequence of modifications that give your Mazdaspeed the most power per dollar, improve drive-ability, and combine the appropriate supporting modifications to protect against failures.

Rear Motor Mount

First up is to replace the Rear Motor Mount (RMM).  This isn’t the most obvious best first modification since it doesn’t do anything to improve power but it definitely transforms the feel of the car.  The mount provides better traction, most notably during aggressive launching, where wheel hop is significantly reduced.  Also, since this is the only motor mount on the vehicle arranged perpendicular to the motor’s torque, it being more stiff helps the longevity of the other mounts.


Now that your rear mount is a little more stiff and you’re better able to get the power to the ground, it’s time to make more power!  The Accessport is the best bang for your buck modification.  For $650, your Mazdaspeed will gain about 30hp and 30tq to the wheels over stock!  That amount will be the difference between night and day on a stock vehicle.  Aside from the power gains, the Accessport will also give you the ability to datalog/monitor several parameters the ECU sees in real time, change to other Off The Shelf (OTS) maps as you continue to add modifications, read and clear codes, estimate power and get 0-60 times, and other cool features.

Intake and Turbo Inlet Hose

Next up is the Intake and Turbo Inlet Hose (TIH).  These modifications will allow you to pick up some power, improve the looks under the hood, and make all the turbo noises much more audible.  Both pieces are easily installed and the proper calibration is only a few button presses away on the Accessport.

High Pressure Fuel Pump

It should be noted that there are OTS maps offered on the Accessport for a completely stock vehicle but we have seen that some vehicles require an upgraded high pressure fuel pump even on the Stage1 power level.  This is especially true for vehicles at an elevation near sea level and/or in extreme cold where air is particularly dense.  If this describes your area, it’s not a bad idea to complete a high pressure fuel pump upgrade prior to the intake/TIH install.  Either the complete pump or simply the internals can be upgraded to provide adequate fuel pressure.  Check out an earlier post for details on how to determine whether your vehicle has adequate fuel pressure.  Even if it’s not completely necessary at your current power level this upgrade will allow you to continue down the upgrade path without worry of lean conditions that come with inadequate fuel pressure.

Spark Plugs

While we’re on the supporting mods, this is also a good time to replace your factory spark plugs.  The factory plugs are capable at the stock boost levels but the OTS maps from here work much better with upgraded spark plugs.  We recommend a 1 step colder plug with a plug gap of .026” – .028” (0.66mm – 0.71mm) be used.  Denso currently offers this spark plug as part #ITV22 (verify each plug is properly gaped before installing them).


Front Mount Intercooler

Replacing the factory intercooler with a front mount intercooler (FMIC) is next up.  The factory top mount intercooler can easily be over worked and overheated due to its smaller size.  Couple the small size with its location directly over a hot engine and it’s no wonder this makes for a good upgrade.  These issues cause intake air temperatures to rise which create a loss in power.  With the COBB Tuning Front Mount Intercooler you can ensure that your engine is receiving the coolest possible air allowing more power to be made.  To take advantage of the lower intake air temperatures provided by the FMIC the proper calibration is only a few button presses away on the Accessport.

Downpipe or Full Turboback Exhaust

Now that we’ve upgraded the intake side of things and cooled the charged air, it’s time to open up the exhaust.  Not only will a turboback exhaust look good and sound even better, it will allow more free flowing air yielding greater power.  The turboback exhaust consists of the entire exhaust from the turbo to the rear of the vehicle.  The downpipe section (exhaust piece bolted to the turbo) comes in 2 pieces from the factory.  The upgraded COBB downpipe replaces both with a single section.   While there are some products which replace one of these two sections, replacing both pieces of the downpipe offers the most power gains and is required to run the compatible OTS map.  The remaining parts of the exhaust are included in the cat-back section.  The Stage 3 COBB OTS map requires the previously listed modifications as well as the full turboback but the factory cat-back system actually flows pretty well.  Peak power can be had with the COBB cat-back also installed but the map can be used with only the downpipe portion of the exhaust upgraded.  However, if the most possible power and improving the sound and aesthetics are important to you, the cat-back is a good modification to include.

The recommendations after this level will vary depending on the goals you have.  Some goals can be reached through different fuels and custom tuning while others will need bigger turbos and additional modifications.  If you’re considering going beyond this list contact a COBB Shop or Protuner near you and they can help achieve your goals!






Jay Noble on May 13, 2016 says:

Nice write-up! I ended up doing most of this back when I had my speed 3 but in a different order. Now that I have a WRX, it would be great to see a similar upgrade path for that vehicle. I’m already stage 2 but maybe I’m missing something you would recommend for a more complete system. Thanks!

Ryan Shehan on November 5, 2017 says:

If i have only the following mods: Apv3, rmm, sri, tih, do i need to do hpfp right now or can i wait till i do downpipe, located in Florida if that matters.

    Marshall on November 6, 2017 says:

    Hey Ryan, you -should- be okay with the factory HPFP in your current configuration. It is always good practice to keep an eye on rail fuel pressure to make sure it isn’t dropping during pulls. With the installation of an upgraded downpipe and moving to a Stage 2 OTS Map you should definitely upgrade the HPFP.