We now offer ready to go regulators without a core required!
Please check the customization options above and choose "Send us a core" if you want the $130 option, then box up your known good regulator and send it to us so we can modify it for you. If you do not want to send us a core, or do not have the time to do so, please choose the "Use our core" option. We have a stock of ready to go regulators for those of you out there that need one quick or do not want to sacrifice your current regulator to the race gods! Please look at the availability (in red by the price) to see the current availability.

What's the scoop?
What we are offering here is YOUR factory, OEM Mazda fuel pressure regulator modified to be made adjustable by adding our custom fabricated mechanism. Just send it to us and we totally transform it into a trick adjustable factory quality regulator.

Why is this better than the other adjustable fuel pressure regulator kits out there?
Our kit is better because it utilizes the factory fuel pressure regulator, which is a practically flawless part to begin with. We've never had or heard of a problem with one for the 5+ years we've been racing Miatas. Also, our kit does not have anything to do with modifying or altering the path of your fuel lines. We don't require cutting into your fuel lines, which causes potential for leaks and fire. It uses the factory vacuum line, which keeps the pressure consistent, something that you will not get with a universal adjustable fuel pressure regulator. Universal fuel pressure regulators dip and spike with different engine loads and rpm spikes (missed shifts), ours stays consistent just as your factory regulator would. We didn't take the easy way out with this and use a universal adjustable fuel pressure regulator, we put a lot of thought and development into this part and have been track testing it for the last couple of races in the 2010 season down here in Florida.

What will it do for my Miata?
Our fuel pressure regulator will allow you to adjust your fuel pressure at your fuel rail from a low point of 22 psi to a high of 58 psi (all regulators might not be the same and individual results might vary depending on the quality of regulator sent to us) by simply turning an adjustment screw which in turn alters your air/fuel ratio by increasing or decreasing the fuel pressure to your engine. Adjusting your fuel pressure lower or higher will lean or richen your air/fuel ratio, which is essential for tuning your Miata's engine for maximum horsepower, especially in stock based classes like Spec Miata where modifications are extremely limited. For example: dialing in more fuel equals a richer mixture of air and fuel, which will benefit low rpm torque and horsepower for tracks that are tight and have low speed corners. Dialing in less fuel will lean your mixture of air and fuel, which will benefit high rpm horsepower for tracks that are 3rd gear through 5th gear tracks and do not have tight turns. So, in essence, our product will allow you to adjust your fuel pressure freely, which in turn adjusts your air/fuel ratio for different tracks based on your need of more horsepower or more torque.

What will I need to use this regulator on my car?
Using our regulator is as easy as removing the factory regulator on your car, sending it to us, then reinstalling it back on your car. It is the factory regulator, so there is no worry about the fit and finish. When you install your new regulator, simply follow your cars repair manual for "fuel pressure regulator removal/installation". We suggest setting your fuel pressure to the factory setting range of 32-38 psi at idle, then tune from there. To properly tune, You MUST have a fuel pressure gauge either installed full time inline with your fuel line, or an external attachable gauge to dial in your specified fuel pressure while idling in the shop. Of course we would suggest adding on our 5X Racing Inline Fuel Gauge Kit by choosing it from the drop down list above. And, we HIGHLY suggest picking up an air/fuel ratio gauge, such as the Innovate Motorsports LC-1 kit we sell here at 5X Racing to be able to accurately monitor and dial in your fuel ratio. If you don't have a fuel pressure gauge, or air/fuel ratio gauge, our regulator is practically useless to your tuning needs.

Ok, I want one! What happens next?
Upon purchase, we will confirm your order and email you with a ship to address to use to send us your regulator. We will confirm the arrival of your regulator, convert it to a 5X Racing Adjustable Fuel Pressure Regulator, and once completed we will provide shipping info on your order when it ships back out to you. Simple as that! We can alternatively convert a brand new Mazda OEM fuel pressure regulator for you, this will add about two weeks to your order and also the price of the new regulator.

Please contact us for any additional questions, we'd be happy to help you get "adjusted"!

Recommended Products:
Innovate Motorsports LC-1 Air/Fuel Ratio Kit