So I am installing a 45 dcoe on to my mildly streetported S5 engine with Stock SE pump and will be using the mallory 4309 FPR. My question is the weber only has one inlet for fuel but the 4309 is set up for return fuel and i need to utilize that since im using the SE pump. So does the return line just come from the FPR and sucks whatever fuel isnt used going to the carb? Also where on the FPR should i hook up the return?

 

As far as I remeber isn't the 4309 regulator for carb applications?

 

I was told my a few other members that they had been using the mallory 4309 FPR on a 13b weber 45dcoe with stock SE pump. I was told to use a rising rate FPR.

I am kinda thinking that at the FPR whatever fuel isnt allowed through I.E. 4-6psi. The regulator will be forced to go return. So 40 psi back to tank.

On some other FPR i noticed they didnt have the option for return or even a guage off of the FPR. The 4309 has 4 ports and 1 vaccume for Boost hence the rising rate FPR.

Here are some pics if this can help?

 

The return for the 4309 comes out of the bottom port of the regulator. A single side port goes to the carb, the 2nd can be used for a fuel pressure gauge, the 3rd side port for supply and the 4th one is plugged.

Doc, the 4309 is the recommended fpr to use with FI or high volume pumps to bring the fuel pressure down for carb useage. It's biggest drawback is that the fuel line sizes need to be increased to handle the extra flow. Since the SE fuel supply and return lines are the biggest ones on any 7, they should work fine.

If one goes to Mallory's website, they will find an installation and useage PDF file for the 4309. Correct fuel supply and return line size is critical fo thier proper funtrion. Another benefit of the 4309 is that they have a boost reference port which can be used in turbo blowthru applications.

 

Thats how i have mine setup trochoid. Thanks for the confirmation. As soon as i recieve my 50ft of 2/0 wire i can get this motor dropped in and take some more pics,