PRL 2015+ WRX FMIC vs Top Mount

PRL 2015+ WRX FMIC vs Top Mount

We spent the past 3 days testing out our FMIC and putting together data for the pubic! The results? ...Well we couldn't be any happier!

Let's start out going over the mod list of the test mule:
PRL Motorsports FMIC kit
PRL Motorsports Intake w/ Air Box
PRL Motorsports J-Pipe / Midpipe Combo
Tomei 3" Ti Exhaust
PRL Motorsports TGV and EGR Deletes
Grimmspeed 3-Port EBCS

All testing was performed with in 24 hours with no changes other than removing the previously installed PRL Motorsports stock replacement charge pipe kit and Turbo XS TMIC and installing our FMIC. Previously the car made 317 hp / 337 tq at about 20 psi on 93 octane with a Pro Tune. These numbers are right on par with about every other 2015+ FA20 WRX that comes through our doors. Typically, these cars like to knock with anymore timing or boost.

After installing our FMIC kit, we immediately noticed the cooler IATs and the potential. With the same exact tune, me must stress that there was only about a 6 hp gain, which we expected. Our FMIC kit isn't a magical piece that just bolts on power. This kit is intended to allow customers to run higher boost levels without the heatsoak of a little turbo being run out of efficiency through a TMIC for extended periods of time, and that's exactly what it did.

We turned the boost up to 22psi (which carried much further now due to an efficient intercooler setup), and added a touch more of ignition timing and cam timing. The car responded quite well to these changes by showing gains of 26 hp and 36 ft/lbs of tq at peak and up to 50 hp and 50 ft/lbs of tq throughout the midrange. Keep in mind this is compared to a Turbo XS TMIC (which proved to be quite an exceptional piece as it was). Typically aftermarket TMIC's made 15-30 hp in comparison to a factory TMIC, so factory TMIC's can expect much more of a gain when upgrading to our FMIC kit!




Each pull was within a couple horsepower / tq of each other, the only real differences were with cam-timing, hence some of the larger gains / losses we did while tuning. A few of our pulls neared / surpassed the 380 ft/lbs of tq marker, but we dialed it back.

Here are some logs from when we were testing the previous Pro Tune (notice the boost was lower than 22psi). This should give you guys an idea of how the temps were during the pulls!



We have been begging the Subaru community to ditch the factory "hot-mount intercoolers" for quite some time now and here is exactly why...

Recently, we tuned a 2016 WRX loaded with bolt-ons, but using our charge pipe kit and stock TMIC. We treated this car like every other FA20DIT WRX we tune, but couldn't seem to break the 300 hp barrier with anything we tried. Air temps were just too hot, causing knock throughout the entire power-band. Fed up with the money spent and the fact that we could not crest over the 300 hp mark, our customer decided to take advantage of our charge pipe buyback program and ditched our charge pipe kit / factory TMIC to upgrade to our 2015+ FMIC kit and Company 23 EBCS.
Instantly we saw decreased air temps and big power gains. By the end of the Pro Tune session we managed to see consistent and repetitive power gains of ~ 70 hp and ~ 70 ft/lbs of tq at peak, and even a bit more throughout the mid-range. There is a slight power drop between 3200 rpm and 4200 rpm because the boost curve has changed with the EBCS change.

Keep in mind that these dyno sessions were on ~ 70 degree Southwestern PA fall days, so the weather wasn't even hot. Power differences become even more drastic in the summertime when the days are much hotter. We cannot stress enough how important it is to monitor, maintain and reduce intake temps as much as possible with these knock-prone vehicles. It is the key to making power and improve reliability.


Power: 288 hp / 332 tq before FMIC kit, 358 / 343 tq after FMIC kit


Nameless Cat-back exhaust
PRL Motorsports Intermediate Pipe + J-Pipe
PRL Motorsports Exhaust Manifold
PRL Motorsports FMIC Kit (after PRL Charge Pipe Kit was removed)
Company 23 EBCS
PRL Motorsports Intake w/ Air Box
PRL Motorsports TGV Deletes
PRL Motorsports EGR Deletes

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