New Product Release: Subaru Fuel Rails

Click HERE to see all of the new Subaru products.

Following a successful launch into the AWD market with the Mitsubishi Evolution VIII / IX / X product line, it was only natural to progress to the EVO's arch nemesis, the Subaru Impreza WRX STi. We have been producing Subaru BRZ boxer fuel rails (shown below) for some time with great feedback, so we had a solid base to build on.

Radium Engineering has just released a family of fuel rails and related accessories for the popular Subaru boxer engines. Two fuel rail kits cover models from 2002 to 2015.

The first kit is targeted at the Subaru engines that are equipped with side-feed injectors from the factory. It is well known that tuners prefer top-feed injectors for the cost and vast selection. The Radium Engineering conversion fuel rail kit (shown above) utilizes specially machined injector seats that insert into the fuel injector bores on the TGV housings. These allow the use of top feed injectors in a clean and leak-free package. More information on these injector seats is shown below. Different height injectors can be accomodated simply by swapping out the insulating mounting boss spacers that are included with the kit. Injector compatibility is explained more below and also on the product page HERE.

The other fuel rail kit is a perfect bolt-in option for Subaru engines that originally came equipped with top feed injectors. It can also accomodate different height injectors by swapping out the insulating mounting boss spacers included in the kit. More information on this fuel rail kit can be found HERE.

Both kits utilize fuel rails that are machined from 6061 aluminum and followed up with bright dipped black anodizing and laser engraving. Each fuel rail is equipped with three 3/8" NPT ports (one on each end and one on the bottom).  This allows the rails to be plumbed in a wide variety of configurations. More information on plumbing the fuel rails can be found on the product pages in the "More Details" tab.


Why Radium Engineering Fuel Rails?

These fuel rail kits cover a large range of Subaru vehicles that go all the way back 13 years. There are dozens of aftermarket fuel rail kits currently available. So you ask, "Why spend time developing products in a saturated market?" Well quite honestly we found a few areas that can be improved.

More than any other engine, the Subaru's horizontally opposed 4 cylinder is extremely vulnerable to poor fuel delivery. The most common symptom is the lean spike stumble seen on many applications. Like all Radium Engineering fuel rail kits, we are the only to offer an optional integrated fuel pulse damper. Many manufacturers skip on this vital piece with the assumption that large bore rails are not suseptable to the issue. However, gas is not compressible. The opening and closing of the injectors creates pressure pulses in the fuel rail which can lead to unstable fuel pressure. In order to achieve a safe and consistent rail pressure, a pulse damper should be used (especially with high flow injectors). The internal diaphragm absorbs oscillating pulses and helps stabilize fuel pressure. This correction can be measured throughout the RPM range and can often help an erratic surging idle. The fuel pulse damper (shown below in center port) can be used in any of the three 3/8" NPT ports on the Subaru fuel rails.

The restrictive 0.19" (4.8mm) ID OEM cross-over fuel piping can also contribute to fuel pressure issues. With excess fuel demands from larger turbochargers, this problem only gets worse. The Radium kit comes with four -6AN fittings for large 3/8" (9.5mm) hose and can be configured in parallel (depicted below) which many Subaru tuners are convinced is essential for the Subaru fuel system. Many other plumbing methods can be used as well (series, parallel, dead end, etc).

Taking every last measure to reduce heat input into the fuel system, machined phenolic mounting spacers and washers are included to completely isolate the fuel rail from heat transferred from the TGV housings and mounting bolts.

Two sets of these press-fit phenolic spacers (8 total) and matching hardware are included in this kit to suit different height fuel injectors. The kit is designed for specific injector heights for proper fitment. Upper and lower O-ring spacing requirements are depicted below for the Top Feed Upgrade Kit.

and here for the Top Feed Conversion Kit

The 20-0168 Top Feed Conversion Kit also comes with 14mm injector bore billet injector seats. These actually snap into place and seal with Viton O-rings. They are anodized and laser etched for a long lasting surface finish. They can be purchased separately HERE .

For the owner of the less common Version 8/9 JDM STi intake manifold that does not use TGV housings, we have a 20-0172 Billet Adapter Kit that allows for the use of our top feed fuel rail upgrade kit.

As previously mentioned, all 3 ports of each fuel rail are tapped with 3/8" NPT. This allows for the use of our billet FPR adapter if an OEM fuel pressure regulator is used.

Click to see all of the new RADIUM products for the Subaru Impreza WRX, Impreza STi, Legacy GT, and Forester XT.

New Products for the 2015+ Subaru WRX
Radium Engineering has just released a range of products for the 2015+ Subaru WRX with the FA20 engine. These products are designed to improve the driveability and performance of the WRX without sacrificing reliability. 
The WRX version of the FA20 engine is equipped with tumble generator valves to assist with emissions during cold engine temperatures. These devices also impede air flow in the intake manifold runners. By eliminating the obstruction, a clear airflow path is established. The Radium Engineering TGV deletes are machined from 6061 aluminum and anodized green or black. Installation is quick and easy (compared to EJ-series engines) and can be performed in about 30 minutes.

The tumble generator valves are an emissions control device, and as such should be removed only for vehicle operating off-highway. It is also recommended that a complimentary engine management tune be implemented to take full advantage of the TGV deletes. No permanent modifications to the vehicle are necessary to install the TGV delete kit.

Even with low mileage modern cars, oil accumulation in the air intake stream can happen. The Subaru FA20 engine places the turbocharger down low, in front of the engine. This leads to oil from the PCV system collecting in the turbo air inlet pipe, down near the turbocharger. This oil is result of blow by coming through the crankcase ventilation system. This oil will eventually be digested by the turbocharger and deposited through the charge piping and can even result in blue smoke from the tailpipe. 

The Radium Engineering Dual Catch Can Kit intercepts the PCV gasses and traps the oil and other pollutants before they can make it back into the intake stream. The kit tucks in perfectly on the RH side of the engine bay next to the ABS module, mounts to existing engine bay fasteners and requiring no relocating of engine bay components. The front catch can intercepts the crank case vent hose that connects to the turbo inlet pipe, keeping oil out of the turbo inlet. The rear catch can intercepts the PCV hose coming off the block and going to the intake manifold, keeping oil out of the intake manifold. The catch cans are designed to withstand boost pressure and are sealed, so direct connection to the intake manifold, even with forced induction, is OK.
This kit is perfect for a street driven car experiencing mild amounts of blow-by.

For more race-centered applications, or cars with built high-powered engines, more oil blow by is usually experienced, often overwhelming the volume of the standard Radium catch cans.  For these applications Radium Engineering applied it's Air/Oil separator to the FA20 engine.

The Air/Oil Separator functions in a similar manner to the catch cans, however, the big difference is that oil is returned back to the engine, rather than stored in the catch can. But catch cans do not only catch oil, they also catch water condensation and it is not ideal to have this water mix with the oil, then return it to the engine. To remedy this, the Radium AOS is heated with engine coolant. This keeps the water vapor from condensing and mixing with the oil.

Engine coolant is plumbed through the bottom plate of the AOS.

Another important aspect of the AOS is that it does away with the function of the PCV valve. Instead, the engine is allowed to breathe freely from both the crank case vent port (at the front of the engine) and the PCV valve port (under intake manifold). The PCV valve is removed from the engine block and replaced with Radium's custom made PCV delete fitting, shown below.

This fitting screws into the block and adapts to a -10AN male. It is straight through, with no check valve or any other device built in. This allows maximum ventilation to the AOS through this port. This is also the path for collected oil to drain back to the engine block.
With both engine ports breathing freely into the AOS, the AOS needs to be vented to atmospheric pressure. This is done by routing the AOS side port back to the turbo inlet pipe. This creates a closed-loop system.
The AOS was designed to mount in the engine bay near the brake master cylinder (for LHD vehicles only) using the Radium Master Cylinder Brace for the 2015+ WRX as the mounting point.

The master cylinder brace is a simple and effective way to reduce firewall flex resulting from brake pedal pressure.It is machined from 6061 aluminum and mounts to the strut tower using pre-existing threaded holes. Clearly visible in the photo below are the three threaded holes in the brace where the AOS bracket attaches.  The brace is sold as an individual item, or as part of the AOS kit.

While installing an AOS kit can be done with the stock fuel feed hose, Radium offers an aftermarket fuel feed hose replacement that cleans up the fuel routing and offers better clearance with the AOS. The hose has a PTFE core that is compatible with all fuel types and also features machine-crimped end fittings.

For all of the products shown here, and a few more, please click HERE.
New Product Release: Subaru AOS and Oil Catch Cans
It is well known that Subaru engines are prone to excessive blow-by, creating a collection of oil and other contaminants in the intake system and intercooler. Do you ever see blue smoke in the rear view mirror? This is typically the contaminants getting burned through the combustion process. 

Shown above is a Subaru valve cover vent crossover pipe that is almost completely clogged with oil residue and carbon build-up.

Radium Engineering Solutions

1. Dual Catch Can Kit
For street driven or lightly modified vehicles, a simple oil catch can system will often do the trick. Radium Engineering has utilized its compact catch cans to created an integrated package for installation into various 2002-2014 Subaru engine bays. The catch cans are designed to collect and retain the oil and other contaminants, preventing them from being cycled back through the engine's air intake and intercooler system.
                                              CLICK HERE to learn more about the Radium Engineering catch cans.

The Subaru Dual Catch Can kit mounts on the RH stut tower and includes two catch cans. The forward catch can is plumbed in-line with the valve cover crankcase vents. This catch can filters and cleans the gasses before they are drawn into the intake pipe. It is responsible for keeping blow-by oil and other pollutants out of the turbo inlet pipe, turbocharger, and intercooler during high engine loads. The rear catch can intercepts the vacuum hose between the intake manifold and PCV valve. This catch can keeps oil and sludge out of the intake manifold. It functions when the engine is in vacuum and the PCV valve is open. The PCV system dynamically changes depending on the throttle body position. See below:

As shown above, when the throttle is closed, the one-way PCV "check" valve opens.

When the throttle is open, the PCV valve closes and all the crank venting is happening through the valve cover vents. The air being sucked in by the turbocharger helps create negative pressure in the intake pipe, which then results in a mild vacuum to the crankcase vent catch can, to help draw out the gasses. In all engine load scenarios, the PCV system promotes negative pressure in the crankcase that can extend engine life.

With the kit mounted in the area of the turbocharger, protection from heat is accomplished with a modular heat shield (shown above). This is necessary to keep the temperature of the catch cans down and help promote condensation of water vapor inside the catch cans where it is collected along with oil and unburnt fuel. The catch cans should be periodically checked using the dipsticks and drained as needed. To dispose the fluid, simply remove the 4 heat shield mounting bolts with a 3mm Allen wrench. The lower half of the catch can bodies unscrew for easy servicing. Always properly dispose of the contaminants. Do not pour catch can contents back into the engine oil.

Click here for the Subaru Dual Catch Can Kit product page

2. Air Oil Separator (AOS) Kit
With a higher engine power output comes an increase in oil circulating through the crankcase ventilation system. Horizontally opposed engines, in particular, expel an excessive amount of oil through the ventilation system. In extreme cases, this may overwhelm the capacity of the standard sized catch cans during long track sessions. Instead of using a large reservoir to retain all the collected contaminants, the oil can be returned to the pan. However, this process must take into account several considerations in order to function properly. 

Shown above is the Radium Engineering Air Oil Separator (AOS). The AOS is built on the foundation of the Radium Competition Catch Can, but with a new specifically designed bottom plate. Full CNC construction, sealed with O-rings and anodized. The AOS still features all of the same oil baffling media found in the competition catch cans. However, instead of collecting oil, the AOS drains back to the engine through the large baffled -10AN ORB bottom port, shown above.

The bottom plate not only features a large oil return port, it also functions as a heater to prevent water from condensing inside the can. The heater is fed by coolant circulating to/from the engine. The cooling fins, shown above, increase the effective surface area of the heating element. Also, if any water were to make it's way into the canister, it would be trapped underneath the lower density oil in the bottom trench. The center port baffle provides a layer of protection to keep debris from enterning the crankcase. 

For AOS crankcase plumbing, the valve cover vents are routed into the top inlet where the stainless steel condensing material separates the oil from the gasses. The PCV valve is removed and the system is no longer hooked up to the intake manifold (vacuum). The crankcase port in the center of the block (green arrows) is now routed directly to the AOS bottom port with a large diameter -12AN (3/4" ID) hose. The filtered liquid oil is collected at the bottom of the AOS and is drawn into the oil pan through the 3/4" hose. Meanwhile, the clean crankcase air can either be vented to atmosphere (VTA) or recirculated to the turbo air inlet pipe (see instructions for details) out of the side port of the AOS.

The AOS completely disassembles for easy servicing when needed, as shown above. 

Because of limited vertical clearance, special low-profile banjo style fittings were developed for the Subaru AOS kit. These fittings are super compact, yet high flowing. They are machined from aluminum and anodized.

Radium installation kits include all necessary parts for an easy bolt-in process.

Shown above is the AOS system fully assembled with a Subaru specific mounting bracket and fittings.

When installed, the valve cover vent lines "Y" together and are plumbed into the top port of the AOS can. The side port is used as the vent to atmosphere (VTA), or it can be routed to the turbo inlet pipe for a closed system. The bottom port of the AOS can is plumbed with a 3/4" hose to the crankcase vent port on top of the block. This line acts as a way for crankcase gasses to enter the AOS, but also functions as the path for oil to return back to the oil pan.
Click here for the Subaru AOS Kit product page

Both Dual Catch Can and AOS kits are available for the Subaru WRX, WRX STi and Forester XT in the 2002-2014 model year range.

Contact with any questions.

An Unexpected RX-7 Sleeper

We do not feature cars on our blog often, but when we come across something unique, we find it hard to resist. The car featured is owned by a long time friend of ours and has been a project in the works for a few years. It was put together slowly, with care, and everything was done "the hard way" in an effort to make it the very best that it can be. Assembly, fabrication, wiring, etc. was done in a cramped garage in Portland, Oregon. No high dollar tools or 2 post lifts were used. We are talking jack stands with poor lighting.  All custom parts were hand formed using small tools and whatever Harbor Freight had that could do the job. It is amazing that something so clean, unique, dialed, and fun could emerge from that garage.

The car is a 1985 Mazda RX-7. A very clean example that was bought locally and used as the host for a wild engine transplant. It sits on Enkei Bortex F17x7/R17x8 wheels with Toyo Proxes 4 tires.

The exterior is dent free and all the plastic trim is in perfect condition. Notice the custom decal that was made...

The front and rear brakes are directly off a Mistubish Evo 8. Not just the calipers, the complete brake system including the vacuum booster, brake master cylinder, and rotors. The calipers attach using custom fabricated brackets.  Each Brembo caliper was completely disassmbled, sand blasted, then powder coated silver and rebuilt by the owner. All new stainless steel hard lines were bent up by hand.

The super clean interior of the car keeps the totally 80's RX-7 vibe. Much effort went into making sure all factory gauges worked correctly with the new engine and stand-alone EMS. More on that part later. The seats are from a Lotus Elise and are mounted on custom fabricated brackets.

The driver's door panel features a unique touch. The owner hand stitched a new panel and while he was at it, he inset an aluminum "Franken Speed" plaque to play on the Frankenstein engine swap idea.

The underside is just as spotless and just as sorted as everything else. Poly bushings, aftermarket swaybars, Koni shocks, Ground Control coilovers, etc are all put to use keeping the chassis in check. All components were cleaned, powder coated and reassembled with fresh nuts and bolts. The rear differential is a limited slip unit from a GSL-SE, rebuilt by the owner. The 3" stainless steel mandrel bent exhaust was hand fabricated by the owner and exits through a discrete black Vibrant muffler.

A Nissan 240sx rack and pinion with power steering was retrofitted into the front of the car and is fully functional.

Now for the really fun part. When the forward hinged hood is openend, there is something that catches everyone off guard.  What is it?  Is that a....Nissan engine....? Why yes it is. A fully built turbocharged Nissan KA24DE. The short block was machined .040" over and put together using Wiseco pistons and Eagle rods and ARP fasteners. The head underwent hours and hours of hand porting (by the owner in his cramped garage) and received Brian Crower valve springs and oversized valves. The cams and titanium retainers are also from BC. The head was put back on to the block using large 11mm ARP studs.

Supplying boost is a Garrett GTX3071R turbocharger that sits on a custom fabricated stainless steel Schedule 40 tubular manifold (made by the owner) and uses a water cooled Tial 44mm external wastegate fully plumbed into the cooling system using stainless steel hard lines.

The owner sanded down the TWIN CAM 16 VALVE  lettering on the stock valve cover then welded on a laser cut plaque and sanded that smooth. The valve cover was then airbrushed and clear coated. Custom hand-bent stainless steel fuel lines feed the modified AEM fuel rail and ID 1000 injectors. Notice the hand made gussets on the intake runners, those aren't stock.

The aluminum intercooler piping was also all hand fabricated and feeds the Xcessive Manufacturing intake manifold and Nissan/Infiniti Q45 throttle body. Maybe this is a good time to mention the car has working cruise control. The intercooler is a modified unit from a Evo 8 and sits stealthly behind the bumper and under the car. The engine also features an Xcessive Manufacturing cast aluminum large sump oil pan, which incorporates their windage tray and crank scraper.

The owner hand-made the strut tower brace from scratch as well. Under the engine is a matching chassis brace.

Built into the strut brace is a a hydraulic engine torque damper, you would not even see it if you weren't looking. The car uses an OEM RX-7 radiator and an electric fan. The car was converted from distributor ignition to individual coils using GM LS2 coils, mounted out of site in the cowl by the windscreen wiper linkage.

A set of Radium Engineering oil catch cans were used to tackle the blow by gasses present in any turbo engine.

A Radium fuel surge tank and first generation fuel pressure regulator were also used. Notice the custom hand bent stainless steel hard line feeding the engine bay mounted surge tank. Those stainless hardlines run the length of the car.

The Infiniti Q45 remote-mount throttle body cable pulley system was adapted and incorporates electronic cruise control.

The engine is controlled with an AEM Series 2 EMS, tuned by John Reed Racing. The car makes 400whp at 16psi of boost on pump gas (92 octane). The plan is to eventually run race gas in an attempt to hit the 500whp mark.

The owner has driven the car to Southern California and back and drives locally on a regular basis. The brakes work very well and are quiet and smooth with a firm pedal. Power comes on smoothly and linear all the way to redline. It idles perfect, starts up instantly, and overall is a pleasure to drive on the street. Doing everything the hard way seems to have paid off on this build.

See more pictures at our Flickr Gallery HERE.

The Classic VW Bug

When it comes to performance, a 1930's economy vehicle labeled "The People's Car" doesn't come to mind. The aircooled VW Type-1 (Beetle) was commisioned by Adolf Hitler and designed by Ferdinand Porsche. But because this was the longest running, most manufactured, car worldwide, there are plenty of options for creating a custom tailored vehicle. Radium co-owner JP purchased a 1965 volkswagen in 2004 specifically for this purpose. His main goal was to create a unique Subaru powered VW bug that would be capable of doing wheelies on the street.

A couple quick purchases and here comes a brand new 2.5L Subaru STi block...

...and an oversized SuperTech valve job from Tom at Port Flow. JP fabricated a stainless steel muffled exhaust system.

Power was transmitted to the wheels using a Rancho prodrag transaxle with an aluminum spool and Sway-A-Way heavy duty swing axles.

In order to properly operate the twin disc clutch's heavy pressure plate, the VW cable actuation was swapped out in favor of a hydraulic master and slave cylinder.

The VW 4 wheel drum brakes were swapped out for disc brakes with 4 POT calipers from Wilwood (below). A Wilwood adjustable proportional valve was required as well as a line lock for drag racing burnouts, both shown above.

JP wired in the EFI system which uses a AEM Universal "Race Box" EMS mounted underneath the rear bench.

For 5 years the car was transformed and looked great, externally.

But in 2009, JP decided the Bug needed a full restoration as there were some necessary body repairs and quite a bit of rust underneath that needed attention. First thing was to separate the body from the pan.

Next, the old floor pans were cut out and new floor pans were welded in place, shown below. 

The entire chassis was then powdercoated gloss black (above). Also the adjustable beam, tie rods, control arms, etc. were powder coated (below). New QA1 double adjustable shocks were installed to help weight transfer for massive wheels stands

Once the widened Porsche Fuchs wheels were reinstalled, the vehicle was aligned.

After the body shell was painted Lotus Aspen White Pearl and reinstalled, the floor pans were insulated before the carpet was installed.

Four jack points are fabricated from aluminum and anodized Radium green.

The headliner and all of the glass was reinstalled and a roll cage was built to comply with racing standards.

Lightweight power windows were installed in order to avoid window crank interference with the roll cage.

The roll cage ties the chassis, body, and engine together for a solid mount.

A Porsche 993 Turbo OBC tachometer is used with a working coolant temperature and road speed digital display.

The factory 2 point harness was tossed for Sparco 4 point harnesses and a modular harness bar. To avoid snapping a neck with 1960's seats without head rests, retro (period correct) ProCar seats were installed.

Because the VW body is a natural air foil, JP designed a removeable wing to keep the car planted down the track and to aid in cooling the secondary radiator and intercooler.

The angle of attack on the wing is adjustable for optimal downforce.

The revised car kept its classic look with modern touches.

The front and rear fenders were slightly widened in order to fit race tires.

Radium Engineering oil catch cans take care of oil separation from the cam covers and crankcase.

The engine runs flex fuel (E85) and starvation is cured thanks to the Radium Engineering E85 Fuel Surge Tank. Radium Engineering fuel pressure gauges are used for monitoring pre and post surge tank fuel pressures.

The front weels are 15x7 with a -21 offset (shown). The rear wheels are 16x9.5 with Hoosier drag radials.

The classic Porsche headlights use modern HID H4 bulbs. The original turn signals on top of the fenders were deleted in favor of European bullet signals.

With the exception of the VW headlight bezels, the classic chrome was removed in favor of texture black powder coating.

The car will be strapped on the dyno and is projected to make over 500whp thanks to the Garrett GT3076R turbocharger.

1965 VW Type-1 Beetle by Radium Engineering
Subaru STi EJ25 Block and Portflow WRX Heads
Crower Retainers, Springs, and 264 Cams
Super Tech 0.5mm Oversized Valves
Radium Engineering Oil Catch Cans
AEM Alternator Pulley
Unorthodox Crank Pulley
Radium Engineering E85 Fuel Surge Tank
AEM Race EMS, FPR, and Fuel Filter
Aeromotive Fuel Filter
RC Engineering 1000cc/min Injectors
FJO 1000cc/min Staged Injector Solenoid
Radium Engineering Fuel Pressure Gauges
GM Flex Fuel Sensor
550hp Garrett GT3076R
DEI Turbo Blanket and Wrap
DC Sports Header, Up Pipe, and Muffler
Radium Engineering Boost Solenoid
STi JDM Intake Manifold
RC Engineering 65mm Throttle Body
Turbonetics BOV
K&N Air Filter
Spearco STi Intercooler
SPAL 6.5" and 14" Fans
Fluidyne Radiator and Oil Cooler
C&R Aluminum Radiator

Rancho Pro Drag with Rhino Case and Aluminum Spool
KEP Twin Disc Clutch Kit, Flywheel, and Engine Adapter
Sway-A-Way HD Axles
EMPI Shifter
Porsche Widened Fuchs, 15x7 (-21), 16x9.5 (+5)
Wilwood 4 POT with Proportional Valve and Line Lock
CB Performance Rear Disc Brakes
KCW Adjustable and Narrowed 4" Beam
Sway-A-Way HD Springs
QA1 Double Adjustable Shocks
Car Creations Front Hood, Deck Lid, Widened Fenders
Porsche Speedster Headlights
Aero Catch Hood Latch
Sparco 5 Point Harnesses and Steering Wheel
CNC Pedal Assembly and Slave Cylinder
Porsche 993 OBC Tachometer
Scat Pro Car Seats

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