Not every story is filled with butterflies and rainbows. Some stories start out very dark and dismal...this is one of those stories. Dan's STi came to us not as an STi, but merely an engine. An engine in poor health, brought in for an inspection and damage report. What was found was a combination of great engine components, mixed with poor assembly practices. These horrible assembly practices would ultimately lead to this engine's demise. It was doomed from the first key cycle.
From here, we worked up a game plan for the next course of action. After some time and discussion with this vehicles owner, the goal was somewhat simple. A daily driver car to run on standard 93oct pump fuel. Something that's still very responsive on the street without much turbo lag and can make over 400whp. Lets talk about how we did it.
This build starts off with a Procom Racing S2 Shortblock. This block consists of a brand new OEM EJ25 block, Manley platinum series forged pistons, Manley H-beam connecting rods, King engine bearings, and an STi forged crankshaft. This block is suitable for up to 500whp, so it'll be right at home on this build. From here, we moved on to the cylinder heads. We took a very simple and budget-conscious approach here and maintained the factory valvetrain, but with the addition of Brian Crower stage 2 (272* duration) camshafts. These camshafts work well with the factory valvetrain and do not require upgraded valve springs, etc. They'll supply a very nice gain in the higher portion of the rev range with little to no loss in spool up or low end responsiveness. The shortblock and cylinder heads are then clamped together with the help of ARP 2000 head studs. From here, the engine then received our standard Procom Racing "Engine Fit Up Kit". This kit includes all needed components to assemble the engine as well a new 11mm oil pump, oil cooler, Gates timing belt kit, etc.
So now that we've built a formidable foundation for this build process, lets talk about what will be feeding this engine air and fuel. Starting with the induction system, we opted for a Blouch Dom2.5XT-R turbocharger. This is a stock location turbocharger meaning it's a direct replacement for the factory unit. It's one of our favorite stock location turbochargers as it offers extremely quick response and packs a serious punch. The air ingested and compressed by the turbocharger is then fed through an ETS front mounted intercooler before making it's way into the engine.
So what about fueling this fire? Ok...
The fuel system on this car starts with a Walbro 255 fuel pump that is housed within the factory fuel pump sending unit. That fuel then makes its way though our Procom Racing "Firewall Forward" kit before being injected into the engine though a set of Injector Dynamics ID1050x fuel injectors.
After this air and fuel mixture is spent within the engine, the exhaust gases make their way out of the engine through a Tomei equal length header, a Tomei up pipe, and finally though an Invidia N1 exhaust system.
Helping to keep this engine cool is though all this abuse is a CSF aluminum radiator and keeping crankcase pressure at bay is a Crawford Performance air/oil separator (aka: "AOS"). An AOS is an essential item on an engine, even a stock engine, and is standard with every engine build we offer. It works as a chamber that the engine can breathe into, and keeps non combustible engine oil out of your intake tract. This leads to longer engine life and a more consistent power output. Oil, being a non-combustible, can cause engine knock which can lead to engine failure if left unattended, so an AOS is a "must-have" modification on not only built engines, but stock engines as well.
The drivetrain in the car is fairy simple as well. The STi drivetrain is extremely stout and doesn't need much attention for street / light track use. We've only added an Exedy clutch to be sure the power can be seamlessly transferred from the engine to the transmission. From there, the car is finished off with Hawk brake pads, Stoptech Rotors, and a freshly refinished set of STi BBS wheels. These wheels were refinished by our friends over at Shore Polish & Finishing. Check them out.
Overall this build is fairly mild, but it's also one of our personal favorites. A build that's exceptionally reliable, doesn't require much added maintenance, runs on pump fuel, and offers exceptional power delivery on the street and track. A build that's easy to drive, easy to service, and easy to have fun with. I hope you enjoyed this Spec Sheet blog and be sure to check out all of our previous blogs and stay tuned for the next edition! We're playing around with the format and what was once a weekly deal, turned into a bit much for us so we've backed it down to every two weeks with plans to add in other segments. Maybe a tech segment? Product reviews? What would you like to see? Let us know on Youtube and our social media outlets what we should do next. Thanks!
POWER AT THE WHEELS: 450whp / 430wtq @ 25psi
-PROCOM RACING S2 Shortblock
-OEM Block Case Halves
-STi Forged Crankshaft
-Manley H-Beam Connecting Rods
-Manley Platinum Series Forged Pistons
-King Main and Connecting Rod Bearings
-BC S2 Camshafts
-PROCOM RACING PRO-Series Oil Filter Adaptor w/ Wix Street Filter
-ARP "ARP2000" Headstuds
-Crawford Performance AOS
-CSF Aluminum Radiator
-Cobb V3 AccessPORT
-PROCOM RACING Protune
-Omni 4-bar MAP Sensor
-Walbro 255 Fuel Pump
-PROCOM RACING "Firewall Forward" Fuel Kit
-Perrin 6-port Fuel Pressure Regulator
-PROCOM RACING Billet Fuel Rails
-AN Fuel Line (-6an)
-Injector Dynamics ID1050x Fuel Injectors
-Blouch Dom2.5XT-R Turbocharger
-PROCOM RACING Short Ram Intake
-Perrin Performance Inlet Pipe
-ETS Front Mounted Intercooler Kit
-Tomei EL Header & Up pipe
-Invidia N1 Race Cat-Back Exhaust System
-Torque Solutions CNC TGV Housings
-STi BBS Wheels
-Yellow Race Systems Coilovers
-ATi Gauge Pod
-AEM Digital Gauges (Boost, Air-Fuel Ratio, & Oil Pressure)
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