damn nice find! its shorter too which should make for an even easier install. Your still going to need the hobb switch activated harness because there is no way the OEM wires are going to feed this.

There was a decent writeup on Radium's website comparing the new 525 to the older 400 pump. See here: http://www.radiumauto.com/Blog/Post/...-F90000285-109

Taken from the article I think this sums it up perfectly "Our data shows us that the F90000285 pump flows 8% more than the F90000274 pump, but in order for that to happen, it has to draw 15% more current. So it is essentially the same pump, but using more current to drive the electric motor harder"

So take that for what its worth. Could it replace a double pumper with 2x 400 pumps perhaps? I guess its similiar to when the 400 first came out and people were saying wahoo no more double pumper with 2x 255s. Regardless upgraded wiring will need to be taken into account for sure with this pump for it to flow what it claims it can do on paper.

Very good info here. I suppose the only way around that is to do the STM relay hardwire kit with low gauge wire. Based on Radium Engineering's research, this is a pump that if you have a walbro 450, and you're just shy of meeting your hp goals, this is the pump to toss in the tank next. There's only so much more flow they can extract from a pump with about the same form factor as it's predecessor.

also... the stock siphon may not take that much return flow...

I see. So there will be a point where even the drilled out siphons will not be enough to handle the return. Someone with CAD software should 3d print a new, larger outlet siphon that handles increased fuel return flow, doesn't ove run the stock FPR, and keeps the siphon effect. If I upgrade my turbo one day, i'll definitely be trying a boost a pump.

im sure a drilled one would handle it.

but the last one i had drilled, never seemed to consistently keep the tank even...
the fuel gauge was always acting funny.

One major issue with the OEM EVO 8-9 fuel pump hanger is the restrictive return port and venturi jet pump. When using aftermarket high-flow fuel pumps, the OEM jet pump becomes too restrictive creating unwanted backpressure in the regulator return line causing excessive fuel rail pressure. The Radium fuel pump hanger includes Radium's own proprietary venturi jet pump with interchangeable orifices to minimize back pressure.

I wish people would stop calling these 525lph pumps. They flow 524 at 16psi which is basically *never*.

It would be like calling the F90000274 a 490lph pump, which it isn't ever in it's operational range on our cars.

Please at least baseline quote their LPH at 43psi:

F90000274: 422lph
F90000285: 459lph

Which means you are getting 37lph (8%) more flow at idle with the F90000285 over the F90000274.

Just so happens it's 8% more flow all the way up to 95psi as well.

I have no personal experience with this pump.

This pump is for those who have already maxed out their walbro 450's and need 8% more flow to achieve their goals without having to switch to a double pumper and hobbs switch (about 700whp). This pump will consume more current than a Walbro 450.

Yay if you have are hardwire kit and a drilled siphon already and you want it to get it over with.

Nay if you already have a walbro 450 and don't need an extra 8% more flow or have nothing wrong with your current setup.

You can skip the hobb switch if you install your parallel power source by copying FP relays 2 and 3.

You end up with a reverse feed problem holding them open. Hobbs switch is just the easiest way to do it. There are other ways, but they are more complicated. To be clear though, you do end up paralleling the hobbs switch controlled relay with the factory stuff.

Mine has been working fine since my last tune. Although I drive it so little (about 200 miles every month). Lol
It sits for weeks at a time (good thing I have a regular full size battery).