Another benefit I am seeing with the in-tank surge design is the surge overflow. Odd that I don't really see it mentioned anywhere (even on radium's website). On external surge tanks you need to return excess fuel from the rail and the lift pump back to the main tank. If you force all returning fuel from the rail to the surge tank with a passive return from the surge to the main tank, positive fuel pressure can develop in the surge tank depending on how well the passive return flows. This surge return pressure can even cause excess pressure at the rail that cannot be eliminated by adjusting the pressure regulator. A better solution for me in this case was to use a Y fitting on the return from the regulator flowing to both the surge and main tank. Fuel takes the path of least resistance eliminating excess pressure buildup and still helping ensure the surge is kept full. The passive surge return is still necessary to accommodate excess fuel supply from the lift pump. This is a complicated solution compared to the in-tank design. With the radium setup here, surge overflow literally just spills out into the main tank from the gaps at the top of the surge. Great benefit to this design that I think should also get highlighted.
Silly question, but...does the fuel tank need to be empty/half full during install? My tank is pretty full, and not sure if this will be a problem when installing the lift pump and baffle. Does it just lower and "clip" over the OEM sub tank?
since the FD has one fuel pump from the factory there isnt a trigger wire for a second pump. The stock wiring probably cant handle two pumps so you need to use a relay from the OEM pump trigger and power the second pump direct from the battery with the relay turning it on and off. If you want to stage it, you can do something like use a hobbs switch to make it boost depended or an MSD rpm switch to make it rpm dependent.
Another benefit I am seeing with the in-tank surge design is the surge overflow. Odd that I don't really see it mentioned anywhere (even on radium's website). On external surge tanks you need to return excess fuel from the rail and the lift pump back to the main tank. If you force all returning fuel from the rail to the surge tank with a passive return from the surge to the main tank, positive fuel pressure can develop in the surge tank depending on how well the passive return flows. This surge return pressure can even cause excess pressure at the rail that cannot be eliminated by adjusting the pressure regulator. A better solution for me in this case was to use a Y fitting on the return from the regulator flowing to both the surge and main tank. Fuel takes the path of least resistance eliminating excess pressure buildup and still helping ensure the surge is kept full. The passive surge return is still necessary to accommodate excess fuel supply from the lift pump. This is a complicated solution compared to the in-tank design. With the radium setup here, surge overflow literally just spills out into the main tank from the gaps at the top of the surge. Great benefit to this design that I think should also get highlighted.
You should ask Hert if he needs help with his street fd! Always glad to see a new MotoIQ video with Mike keep it up guys!🤙
Awesome setup
Silly question, but...does the fuel tank need to be empty/half full during install?
My tank is pretty full, and not sure if this will be a problem when installing the lift pump and baffle. Does it just lower and "clip" over the OEM sub tank?
@@catwalkcool thanks!!!
Is there a low PSI (10 or so) pump that fits in this set-up?
I wish they did something like that for the R32 GTR
they did
I bought one like this and I'm struggling where to find the trigger +12v for the second fuel pump. Anyone knows which cable it is on RX7 FD3S?
since the FD has one fuel pump from the factory there isnt a trigger wire for a second pump. The stock wiring probably cant handle two pumps so you need to use a relay from the OEM pump trigger and power the second pump direct from the battery with the relay turning it on and off. If you want to stage it, you can do something like use a hobbs switch to make it boost depended or an MSD rpm switch to make it rpm dependent.
@@motoiq thank you very much for your help.
What rear brace is that?
Is that a new shirt design?
Mike McKay yes, and Martin has the only one lol