{"product_id":"radium-fpr-kit-08-21-subaru-sti","title":"Radium - FPR Kit, 08-21 Subaru STi","description":"\u003cp\u003eThis kit replaces the OEM fuel pressure regulator and damper assembly. The factory STi fuel line routing uses a quasi dead-end system that circulates fuel through the regulator, bypassing the engine. Fuel is only routed to the engine when there is demand.\u003c\/p\u003e\n\u003cp\u003eThe Radium FPR kit reroutes fuel to cycle through the fuel rails before reaching the regulator and returning to the tank. This is the preferred fuel line routing by Subaru tuners trying to address stumbling issues. The kit installs in the same location as the OEM fuel pressure regulator. Also included are vacuum hose and fittings to reroute the vacuum reference line from the #4 cylinder runner to the intake manifold plenum for a more stable vacuum signal. The optional pressure gauge kit 20-0386 (sold separately) can be installed into the unused 8AN ORB port on the regulator.\u003c\/p\u003e\n\u003cp\u003eThe regulator features the first tool-less pressure adjustment. A jam nut and set screw are no longer required. With a simple turn of the knob, pressure will be increased or decreased.\u003c\/p\u003e\n\u003cp\u003e\u003cimg style=\"width: 240px;\" src=\"https:\/\/www.radiumauto.com\/cdn\/shop\/files\/Rotating_Assembly-2.jpg\"\u003e\u003c\/p\u003e\n\u003cp\u003eTo aid in adjusting pressure, there are incremental detents that provide haptic feedback to the user. Every detent permits 1psi (+\/-0.5psi) of adjustment depending on current fuel pressure. A newly designed single stainless steel return orifice generates laminar flow that enhances stability control.\u003c\/p\u003e\n\u003cp\u003eThe regulator also features a 360 degree swiveling vacuum reference port that is double O-ring sealed. This is the first in the industry. It permits the installer to quickly point the vacuum fitting in any direction with no tools required.\u003c\/p\u003e\n\u003cp\u003eThere are 4 interchangeable 10-32 threaded vacuum port fittings provided to cover all scenarios.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eBarbed Fitting: A black zinc-plated 3\/16\" (5mm) barb machined from high strength steel that is compatible with the following vacuum hoses: 5\/32\" (4mm), 3\/16\" (5mm), and 7\/32\" (6mm)\u003c\/li\u003e\n\u003cli\u003e3AN Male Fitting: A black zinc-plated adapter machined from high strength steel that is compatible with 3AN hose ends\u003c\/li\u003e\n\u003cli\u003ePush-To-Connect: A nickel-plated brass fitting with Buna-N O-rings that is compatible with hard plastic 1\/4\" OD tubing\u003c\/li\u003e\n\u003cli\u003eVacuum Plug: A black oxide stainless steel screw that is used to maintain a constant (non dynamic) fuel pressure.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eThis FPR kit is suitable with all gasoline types including unleaded, leaded, oxygenated, and pre-mixes. Furthermore, it is compatible with alcohol blends of fuel including methanol, ethanol, and E85.\u003c\/p\u003e\n\u003chr\u003e\n\u003ch3\u003eABOUT FUEL PRESSURE DROP AFTER SHUTOFF\u003c\/h3\u003e\n\u003cp\u003eSome installations may experience a rapid fall of fuel pressure when the engine and\/or fuel pump shuts off. This is considered normal operation for aftermarket fuel pressure regulators, regardless of brand. \u003c\/p\u003e\n\u003cp\u003eThis can occur due to the diaphragm seat and the return orifice not fully sealing when fuel flow is stopped. For regulators to have the ability to regulate high fuel flow rates, the size of these components must be increased. This creates larger sealing surfaces between the components, preventing them from forming a perfect seal, even with high spring rates. This is not an indication of an issue or defect and it is not a cause for concern on its own.\u003c\/p\u003e\n\u003cp\u003e\u003cspan style=\"text-decoration: underline; color: rgb(255, 42, 0);\"\u003eYou do NOT need to contact technical support about this issue.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003eFuel pressure will reset immediately when the fuel pump is activated again.\u003c\/p\u003e\n\u003cp\u003eIf the engine is experiencing other symptoms such as long cranking to start, or delays in pressure building when cranking, these symptoms are unrelated to the regulator. There is likely an issue with the fuel feed hose draining back to the tank. This is most likely due to an internal leak somewhere in the pump module: possibly a venturi jet pump, or the lack of a fuel pump check valve.\u003c\/p\u003e\n\n\u003cdiv style=\"border-left: 3px solid #e11d48; background: rgba(225, 29, 72, 0.05); padding: 12px 16px; margin: 20px 0; border-radius: 4px; font-size: 0.9em; color: #881337;\"\u003e\n  \u003cstrong\u003eNotice:\u003c\/strong\u003e This product is designed and intended strictly for off-road closed-course motorsport competition and racing vehicles.\n\u003c\/div\u003e","brand":"Radium Engineering","offers":[{"title":"FPR Kit Only","offer_id":67438794637470,"sku":"20-0965","price":391.0,"currency_code":"CAD","in_stock":true},{"title":"Bundle with 0-100psi Gauge (90° ORB Adapter)","offer_id":67438794670238,"sku":"20-0965 + 20-0386","price":506.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0774\/6460\/0734\/files\/radium-fpr-kit-08-21-subaru-sti-1.jpg?v=1790632943","url":"https:\/\/dm-performance.ca\/products\/radium-fpr-kit-08-21-subaru-sti","provider":"DM Performance","version":"1.0","type":"link"}