HIGH PERFORMANCE OUTBACK FUEL RAILS
Here's the answer to lots of power, and good looks. If your targeting for more than 300HP in a 2.5L Subaru motor you'll need to replace Subaru's OE fuel injectors, they cannot deliver enough fuel for turbo boost levels beyond 6 to 7lbs. We recommend high quality Siemens fuel injectors, as pictured here, available in 55lb (as shown) injectors good for application up to ~400HP. We also offer 72lb injectors for those big wahzoo 500+HP motor projects. Outback has FI setups for 2.0L, 2.2L and 2.5L motors, on the shelf.
Why do you need Outback Fuel Injectors and Fuel Rails?
Motors up to 1998 that have DOHC and 48mm crank journals come stock with OE (original equipment) fuel injectors that are absolutely of no use on a sandcar with a turbo. They are so small and deliver so little fuel that you'd be lucky to develop 225HP regardless of the turbo boost achieved. You just won't get enough fuel to do the job.
Motor years 1999 and later with SOHC and 52mm crank journals have larger OE fuel injectors that can deliver a little bit more fuel than earlier OE injectors. These injectors combined with a high pressure regulator can squeeze up to 300HP out of a 2.5L motor, running about 10lbs of boost. That's about the limit with OE injectors that come on SOHC heads.
To achieve big HP you need lots of fuel to mix with the high volumes of air from the turbo charger. High performance fuel injectors are needed to accomplish this, and custom fuel rails are required to adapt bigger injectors to the Subaru head. Outback injector setups are proven and reliable for almost any Subaru motor project for the sand or street. Tell us what kind of HP you're targeting, along with the engine core type, and we'll set you up with the right injectors, fuel rails, and regulator.
Interesting to note, the older DOHC motors, even though the stock OE fuel injectors are smaller, the intake manifold and head ports are larger. Because of the larger ports in the DOHC motor, this is obviously better suited to maximize HP versus the newer SOHC motors which have slightly smaller intake manifolds. When building your engine, some of the race parts are cheaper for the DOHC motor too, such as the racing rods. So if you plan to build 450+HP in your motor you may want to start with the older DOHC motor. But if 300-450HP is your target, the SOHC motor is a good motor that has other advantages that some folks want.
Trade-off to consider:
If you use race pistons with valve cutouts in the dome for non-interference, a DOHC Subaru motor will still bend a valve if you ever lose a timing belt. This is because the separate cams on each head can free-wheel, allowing the valves to collide with each other. This can ruin your weekend and cost lots of time and money. So make sure you inspect your timing belt annually, and replace every 2yrs regardless.
If you use similar race pistons with valve cutouts on a SOHC motor, you won't bend valves if you lose a timing belt. Just simply replace the belt and you're back in the dunes. Losing a belt is not a common problem, unless you don't inspect it annually. But if you like the safety of the SOHC setup, the trade-off of protecting your investment may be worth having a little less HP. But remember, SOHC motors can be built to develop 450HP, and that's nothing to sneeze at.
Last but not least, the slightly smaller intake ports inherent to the SOHC heads will create more velocity of the intake air, so the SOHC heads will develop better low RPM torque than the DOHC heads, handy for duning. Many engine builders like the low end power advantage of the SOHC heads and opt for the trade-off, assuming 400-450+ HP is enough.