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Radium Engineering Fuel Pressure Regulator Kit Black 2008 - 2021 STI - 20 - 0965 - Subimods.com

Radium Engineering Fuel Pressure Regulator Kit Black 2008-2021 STI

$256.45
$269.95
$269.95 - $269.95
$269.95
$256.45 - $256.45
$256.45
-5% -5%
17 In Stock, Usually Ships within 1-2 Business Days
SKU 20-0965
by Radium Engineering

DETAILS

This kit is designed for use in the USDM 2008-2019 Subaru WRX STi (EJ257 only) and replaces the OEM fuel pressure regulator and damper assembly, shown below. 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.

The Radium FPR kit re-routes 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 re-route the vacuum reference line from the #4 cylinder runner to the intake manifold plenum for a more stable vacuum signal. The optional pressure guage kit 20-0386 can be installed into the unused 8AN ORB port on the regulator.

The 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. 

To 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.

The 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.

There are 4 interchangeable 10-32 threaded vacuum port fittings provided to cover all scenarios. 
1. Barbed 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).
2. 3AN Male Fitting: A black zinc-plated adapter machined from high strength steel that is compatible with 3AN hose ends.
3. Push-To-Connect: A nickel-plated brass fitting with Buna-N O-rings that is compatible with hard plastic 1/4" OD tubing.
4. Vacuum Plug: A black oxide stainless steel screw that is used to maintain a constant (non dynamic) fuel pressure. 

This 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. 

Customer Reviews

Based on 5 reviews
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(4)
20%
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J
Jameson
Great quality product

As expected, this kit is awesome. Radium did a great job putting this together, everything went together really smoothly, all the fittings are high quality seem to seal very well. Have been running it for about 2000 miles at this point, without a single issue. Install is also very quick if you follow the instructions. 10/10 would recommend

Jameson,

Thank you for your 5 Star Review! We love that everything installed smoothly and has been working flawlessly. Great to hear it lived up to expectations!

Regards,

J
Jose Luis Garcia
Easy to install

Easy to install, better control of fuel pressure and remedies the infamous stumble. Does not come with a pressure gauge and pressure needs to be properly set without vacuum at 100% pump duty.

User picture

Hi there Jose,

Thank you for leaving a 5 Star Review for the Radium Engineering Fuel Pressure Regulator Kit. We are happy to hear that you found it easy to install and that it has improved your fuel pressure control and resolved the stumble issue. Thanks again for your feedback!

Regards,

L
Louie Ortiz
Simple

Quick and painless install, bummed that it does not include the gauge in the price but honestly not a deal breaker. Overall great quality to price value.

User picture

Louie,

Thank you for taking the time to leave a 5 Star Review. We are glad to hear that you found the Radium Engineering Fuel Pressure Regulator Kit easy to install. We apologize for any disappointment regarding the gauge not being included, but we are happy to hear that it didn't detract from the overall value. Thank you for choosing Subimods! Enjoy!

Regards,

N
Neri Ayala
Good product

10/10

Neri,

We appreciate the 5 Star Review!

Regards,

I
Ian Arvidson
Wow so good!

The product itself was fantastic. Unfortunately I ordered the regulator and the gauge as separate packages and only found out after I was assembling and installing that the ORB adapter to put them together was not part of either the gauge or the FPR packages. Ordered the adapter on Amazon to get it quicker but once I installed, it made such a huge difference in driveability on my 2020 STI. FBO ~370whp on 93

User picture User picture

Ian,

Thank you for sharing your experience and pics of the Radium Engineering Fuel Pressure Regulator Kit in black for the 2008-2021 STI. I am glad to hear that despite the inconvenience with the separate packages and the missing ORB adapter, once installed, the product made a significant positive impact on the driveability of your 2020 STI! Achieving around 370whp on 93 octane with the full bolt-on setup is fantastic! If you have any more comments or need further assistance, please feel free to reach out. Enjoy!

Regards,

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