SAFC II
#9
I think he ment 200 rpm to the redline. You can tune 12 points with the safc in 200 rpm increments. Theoreticly you can't tune 0 rpm.
Anyways, you can't "effectively" tune with the safc because the stock fuel pump has a fuel pressure regulator controlled by the ecu. The piggyback unit struggles to gain control over this making fuel delivery unstable. This is why it is better to use the safc in conjunction with fuel return system.
A DIY fuel return system would not be that difficult to make. I can tell you what needs to be done if your interested.
Anyways, you can't "effectively" tune with the safc because the stock fuel pump has a fuel pressure regulator controlled by the ecu. The piggyback unit struggles to gain control over this making fuel delivery unstable. This is why it is better to use the safc in conjunction with fuel return system.
A DIY fuel return system would not be that difficult to make. I can tell you what needs to be done if your interested.
#10
Senior Member
SL Member
Scion Evolution
Originally Posted by cdubber9
I think he ment 200 rpm to the redline. You can tune 12 points with the safc in 200 rpm increments. Theoreticly you can't tune 0 rpm.
Anyways, you can't "effectively" tune with the safc because the stock fuel pump has a fuel pressure regulator controlled by the ecu. The piggyback unit struggles to gain control over this making fuel delivery unstable. This is why it is better to use the safc in conjunction with fuel return system.
A DIY fuel return system would not be that difficult to make. I can tell you what needs to be done if your interested.
Anyways, you can't "effectively" tune with the safc because the stock fuel pump has a fuel pressure regulator controlled by the ecu. The piggyback unit struggles to gain control over this making fuel delivery unstable. This is why it is better to use the safc in conjunction with fuel return system.
A DIY fuel return system would not be that difficult to make. I can tell you what needs to be done if your interested.
#11
Then, can u do a DIY? or tell us how to with detail instructions?
What you would need to do first is take the fuel rail off and remove the injectors. Weld a male connector on the dead head side of the fuel rail that will connect to your fuel line fitting. Don't forget to drill out the end of the fuel rail after the fitting is welded on. Run that line to a vaccum controlled fuel pressure regulator that can be remotely mounted anywhere under the hood. Run another line from the fuel pressure regulator under the car, between the gas tank and up under the backseat where the fuel pump is located. Then take the fuel pump out, disassemble, and drill a hole in the top for the return. Use a 90 filling with a nut and an o-ring on each face for good seal.
Here's the trickey part, the stock fuel pressure regulator is located within the fuel pump assembly. You need to keep this forced open in order to gain constant control of the fuel pressure. You can mill a plug, weld it, or do whatever neccary to keep it open, but it must be wide open at all time.
Connect the fuel line to the fuel pump return fitting, plumb the vaccum line, dial in you fuel pressure, and tune accordingly.
#20
why would u go through all of this trouble ? just get an emanage , its only a few hundred more then an apexi afc . not to mention im sure that when the vvti is changing the built in fuel pressure reg. is also changing .