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Walbro 450lph+ Fuel Pump Guide

Daelen Snow  June 28 2018

Walbro 450lph+ Fuel Pump Guide

We here at MAPerformance have been building, tuning, and racing in the sport compact community for over 10 years, and the most common goal for any owner of almost every platform we have worked on is that they want to make more power. To make more power there are very few things more important than picking the correct fuel pump that will fit the needs of your car and its intended use. Later on in this segment, we are going to help you try to pick the best pump for your needs, but first, let’s look at the options.

Walbro, one of the most recognized brands in the industry, manufacturing fuel supply solutions for the OEM and Aftermarket since the 1950’s. Since Walbro has been in business for so long and developed so many pumps for OEM and specialty applications, Walbro simply has a lot of options. Normally, options are great but due to how many walbro pumps exist today were originally derived from specific applications, data and fitment information for their universal pumps can be confusing and sometimes hard to discern. Sometimes, too much of a good thing is still too much.

The 450,450 High Pressure, and 525(470) are all identical dimensionality. The 400 is a slightly longer body, and does not have the integrated harness.

We will start with some facts about each of these pumps:

  • The 400lph (F90000262) is the older style 400lph pump good for pump gas applications only, and not really used as much anymore with the addition of the 450s. But this was the pump that really changed the landscape of single pump systems and started to open the door to further options.
  • Both the 450 (F90000267) and the 450 High pressure (F90000274) flow 450lph @ 50psi base pressure
  • The 450 (F90000267) and 450 High Pressure (F90000274) will both Support 500+hp on E85 Fuel and 700+ on pump gas applications. (Turbo cars)
  • The 450 and 450 High Pressure flow near the same until about 80psi (*at the pump) where the 450 will drop off and no longer hold pressure, this bad for high boost applications as it will bleed off pressure and no longer hold steady, possibly causing lean conditions. No downside to running the higher pressure relief valve of the 450 High Pressure for applications not running higher boost.
  • The 450 High pressure will hold steady pressure until 110psi (*at the pump) before is bleeds off.
  • The 525(470) flows 470LPH @ 50psi base
  • The 525(470LPH) Pump is an all new design featuring a dual channel turbine as opposed to the single channel of the past. This is to maximise efficiency at the higher pressures and temperatures that many modern high power turbo cars will see. This pump is designed for the guys running in the 70-100psi fuel pressure range consistently, and will greatly reduce pump fatigue improving the lifespan of the pump. You will see this pump called both the 470, and the 525. This is due to the fact that the pump DOES flow 525lph, but at a very low pressure that will honestly never be seen in a performance application, as such its shown as the 470lph due to the fact that it actually flows 470lph @ 50psi, making the comparisons fair.

Now, with that information, What pump should I choose?

  • The 450 High Pressure (F90000274) will be the standard choice for most applications and power levels, good for all fuels and stable for most moderate boost applications. By far our most popular pump.
  • The 470lph (F90000285) pump will be for those of looking to push the car just a little bit farther without having to jump to a twin pump design. 700+HP will be doable on this pump with E85, 800+hp on pump gas, and it will thrive in the higher pressure environments of modern high boost turbo applications.
  • Keep in mind that when picking a fuel pump based on what pressures will be run, err on the side of caution as most systems do have a larger pressure at the pump than at the regulator due to restrictions of flow in the system (IE: Filter, hoses, fittings, bends, etc)( Ie: 70psi pressure at the regulator could easily be 80psi plus pressure at the pump, causing your normal 450 to bleed pressure and lean out the car. Even though on your gauge, you should be safe.)

Now that you have picked the best option, what do you need to buy for the install of your new 450/470lph pump?

  • The Pump Alone, Pump and hardwired pigtail only for those of you replacing an existing pump.
  • Basic Install Kit, as they are supplied in “Universal” form with the pump and pitail alone. The Install kits in most cases include filter sock, retainer, and wiring connector w/pigtail for those of you installing in most modern cars (Some exceptions do apply where stock wiring will not handle it (IE: Evo X)
  • Hardwire Install kit: although not required, the hardwire kit will provide a safer, and more consistent power supply to the pump. Due to the design the Walbro 450/470 are some of the highest amp drawing pumps in their class. Includes all the same parts as the “Basic Install kit” along with a length of power wire, ground wire, 30 amp inline fuse, 40 amp relay, 4-lead relay socket with pigtails, and the install instructions. This will be the most popular option for those of those of you installing one of these pumps into a car more than 10 years old, or a factory system will not hold up to the current draw of these pumps. In all honesty although adding this is not always a requirement, its almost always a good idea.
  • Due to the size these pumps may require modifications to the hanger or basket for your application, shown above is our install kit for the Evo X and 09+ Ralliart. Although we may not have the answer for every car out there, we would be more than happy to help the best we can with any info you may need!

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