Subaru: The Ultimate Street Car: Pt.1
We're always looking for more...more power, more boost, more FAST, but all this comes at a serious cost. Not just a financial cost, but a driveability cost. Many of these big power cars are built to do one thing, race. They aren't built for day to day abuse, they have power bands that wake up when most of you are shifting into the next gear and honestly...they suck to drive. Some may argue this fact, but I've always had more fun behind the wheel of a 500hp Subaru than a 1000hp Subaru. I know because I built one and that's where this story begins.
BACKSTORY
My 2006 STi "Gretta" was my first big project car. I owned the car for about ten years and it went through many iterations of fast. When the car went from a stock turbo to a rotated set up, the biggest thing I missed was the almost instant torque to throw you in the seat. I would find myself changing cams, turbine housings, etc in search of a quick reacting set up. The best set up I had on the car was a mild cam engine and a PTE6262. The car was relatively quick-spooling and made just north of 500hp on pump / meth. The car was my daily driver (only car I owned) and was good for 10.7@135mph quarter mile passes and would walk past most things on the street. This was back in 2009/10 when a ten-second car was actually pretty fast.
Once I started Procom Racing in 2011, Gretta took a back seat as any and all of my money was used to get this shop off the ground. When I finally got back into working on the car I knew it needed to be badass in order to make waves in the community. Through this, I found out just how many ways you can break an EJ25 and just how much trouble you really find when you start to make 250hp per cylinder. Being on probably the same budget for the car as many other enthusiasts, each set up and problem lead to more wait time. The business was the only important thing to me and the car was seen to me as "fun money" (which I came to find out to be completely backwards, but that's a story for another blog post). Anyway, lets fast forward to 2015. The engine set up is where it needs to be, I have a massive 72mm turbo on the car and the car again eclipses the 250hp per cylinder mark, but the fuel system is spent and more changes need to be made. I take the car out for a drive and while everything turns into a blur past 6000rpm, the time before that is fairly dull. As I'm sitting at a traffic light in this obnoxious, rattle box of a Subaru, I think to myself, "there's gotta be a better way". I was unhappy with the car overall. It excelled in the power department, but was not a comfortable or fun car to drive. Which leads us to this build...
THE CAR & THE GOAL
This street car build will be just that. A true street car. This car will start up every day, go to work, go grocery shopping, go out on dates, it'll even take grandma to church. We're starting out with my brother Joe's, who most of you know, 2005 WRX. I'm essentially using the decade of R&D we spent with Gretta and applying that to into a more usable version. Instead of having 1000+hp of unusable power, the goal with this car is a bit more modest at around 800hp. It'll run on pump e85 through a stock ecu and retain all creature comforts inside and out.
THE FORMULA
ENGINE
Procom Racing - S3 Shortblock
- Closed-deck EJ25 Block
- OEM Heat-Treated Crankshaft
- Procom-Spec Manley Turbo Tuff Connecting Rods
- Procom-Spec Manley Forged Pistons
- Procom-Spec Wrist Pins
- King Engine Bearings
Procom Racing - S3 Cylinder Heads
- Procom CNC S3 Port
- Competition Valve Job
- BC280 Camshafts
- BC +1mm Intake and Exhaust Valves
- BC Valvesprings with Ti Retainers
ARP625 Headstuds
OEM MLS Head Gaskets
INDUCTION
Procom Racing - EFR Twin-Scroll Turbo Kit w/ EFR9180 Turbocharger
Procom Racing - Flipped-Manifold Intercooler Kit w/ RACE core
FUEL SYSTEM
Procom Racing - RACE Surgetank
Walbro 255 fuel pump feeding surgetank w/ Aeromotive Pro-Series External Pump
Injector Dynamics - ID2000 fuel injectors
Procom Racing - Billet Fuel Rails
DRIVETRAIN
2007 STi Drivetrain
Exedy HD Twin-Disk Clutch
The planning for this build started once I took Gretta off the dyno. It was nice to be able to lay down a high number, but overall driveablity suffered greatly to do it on that set up. What we walked away with was a great understanding of what it takes to keep an EJ25 alive at these power levels. We learned a lot as a team with that project and we're now able to refine that R&D into a very usable multi-purpose car. We'll be posting updates throughout the build up of this true "Ultimate Street Car" and will be debuting the car at our annual open house this spring. Stay Tuned!
-LL
