Thraxbert
Well-Known Member
This is the Precision Raceworks AFS.800. The system has two Walbro 535 pumps in the tank, plus the OEM pump. The OEM pump only feeds the DI system, and the two Walbros only feed the PI system. It's a "regulated" system, meaning the fuel pressure is adjustable to hold a very specific value, then increase as more boost pressure is applied. In other words: the PI system turns on when I start the car, and any unused fuel just goes back to the gas tank.I need details! Looks awesome, can you explain what all it does and who installed?
Advantage to this setup, versus something like PFS or Vader, is that that this system does not fight with the OEM fuel controller to set the right fuel pressure. This is especially valuable under WOT, where the PI and DI system (often) need constant correction because the OEM pump is trying to pull back pressure, but the aux pump(s) are trying to add pressure. Any system with a dedicated feed to the PI system should work this way, but I chose the PRW kit for this reason. It makes tuning easier, fueling easier, AFRs safer. All things I wanted. W
The craftsmanship is excellent, the wiring harness is excellent. Personally, I think this should be the go-to solution for most people considering PI. There's also a AFS.460 model with a single extra pump, which would be sufficient for most people. Overall, I'm really impressed, and with three pumps this is my "lifetime setup", which I was also interested in. Buy once, cry once.
Personally, I think this product is also a good deal. I don't mean "inexpensive," just a good deal. Considering extra fuel pumps are already $600+ for DIY kits, or $1000+ for true PnP options, a little extra to get the "best" made sense to me. Custom-made electrical connectors, billet components, no half-assed shit, clean wiring.
Edit: for any tuner who stops by this, we had the best results setting the FPR to 43.5 PSI. It's 1:1 boost referenced. We used solid state relays. We disabled the relay trigger in MHD+, kept the <40 PSI soft limp mode as protection, and then just set PI to trigger @ startup with no throttle input. PI pump is at 30% DC.