In many ways, the front of the car is the best possible location for the intercooler. It gets 100% cold, fresh air blasted directly onto it, so cooling efficiency is maximized. The air doesn't have to flow through any scoops or ducts and doesn't have to turn any corners.
With the older STI turbo layout, the plumbing runs for a front-mounted intercooler (FMIC) were pretty long, but on the 2015+ WRX the turbo is right at the front of the car, so the air piping isn't much longer than for the stock top-mounted intercooler. (It would be shorter if we flipped the intake manifold around so the throttle body faced forward, but that's a discussion for another time.)
The TurboXS front-mounted intercooler kit comes complete with a replacement bumper reinforcement beam/intercooler bracket structure, hard intercooler plumbing and silicone couplers to connect them all. The huge intercooler core is almost three times as large as the stock TMIC core.
See the picture of the TurboXS FMIC kit at right -- the factory intercooler core is on the left side of the photo. Note the tubular-structure replacement bumper beam, which also incorporates a tow hook/license plate mount receptacle.
Installation of the FMIC kit was not as complicated as we feared. We did trim some of the front bumper cover to get everything to fit, but it wasn't as much as we feared, and the intercooler core sits quite nicely and discreetly behind the stock lower radiator grille opening.
To help out on the intake side, we added a Perrin silicone turbo inlet. This part replaces a problematic stock inlet made of plastic. The stock item can crack and leak, so it makes sense to replace it while we're working in that area. The Perrin item is much smoother for higher flow, plus the reinforced silicone rubber construction should hold up for a long time.
At the same time we upgraded the intercooler and the turbo inlet, we swapped in a TurboXS catted J-pipe. The J-pipe is the first exhaust component after the turbocharger, and the aftermarket version from TurboXS has larger 3" diameter plumbing, plus a high-flow catalytic converter to increase flow and power potential. In addition to the bigger diameter and higher flow, the new pipe is all fully-polished stainless steel, so it looks great.
After the new mods we put the car back on the dyno for some more custom tuning. It did much better, at 292 awhp and 281 ft-lbs to the wheels, but that was not as much as we were hoping for, and not as much as some similarly-modified customer cars that we have run on our dyno.
If this was the last stop on our modification journey, we would pull everything apart and investigate why the car wasn't making as much power as we expected, but instead we decided to push ahead to the next phase on this car. Stay tuned for more of those plans in our next post.
On the outside of the car, we installed some STI-style turn signals into the mirrors. The Subaru WRX STI comes with mirror turn signals and standard, but we installed some aftermarket items instead, for some extra pizzazz. Ours feature sequential turn-signal action, plus a white running lamp for when they are not in turn signal mode, and we think they look great. They do require a little extra wiring, because the WRX does not have factory mirror turn signals at all. Our kit includes everything you need, including OEM STI mirror caps with notches in them for the lamps. We wrapped our new mirror caps in black vinyl to match some of the black badging we've been installing around the car.
Finally, on the back of the car there is a little rectangle that looks like it should hold a lamp, but at least here in the U.S., it just has a blank piece of plastic. We fixed that by installing an F1-style brake lamp in that spot. We tied the lamp into the existing brake wiring, so everytime we hit the brakes, the center low-mounted stop lamp comes on. It even blinks when it first turns on, just like the F1 cars.
The lamp comes in a red version, which is what we chose, or a smoke version that is a little more discreet when it's not on.
Products mentioned in this blog post:
- TurboXS 2015+ WRX Front-Mounted Intercooler Kit
- TurboXS Catted J-Pipe
- Perrin Turbo Inlet
- Sequential Mirror Turn Signal Lamps
- F1-Style Rear Brake Lamp