I posted this on a couple other forums as well..

Some of you have been following my monster Proto build, one of the core changes is the e85 conversion. During this conversion we realized that the e85 basically eats the oem rubber lines, gaskets, o-rings etc, so the entire fuel system was removed and rebuilt.

During the rebuild it was pressure tested (thank you for your thoroughness Todd!)and found that the pumps (I have 2 in tank) have a "wastegate" that opens at 5bar and purges the excess pressure back into the fuel tank, well, this is all fine and dandy unless you have a 5bar FPR and if I have this straight in my mind, would you will be getting LESS fuel pressure instead of more?

Am I missing something? Anyone with a 5bar FPR have a fuel pressure gauge installed to verify? I don't have the 5bar FPR, but I know there were quite a few that did and would be interested to see if there were any fuel system issues to correlate to this.

 

Interesting, but isn't stock a 3-bar? If that's the case, you are going to get two extra "bars" with a 5-bar, until the fuel "wastegate" opens. Right? So all the wastegate means is that you are not going to be able to get beyond 5 bars with a 5-bar fpr, but that's all you want with a 5 bar anyway, so no harm no foul, right? Am I missing something?

 

seems odd, you'll hit 5+ bar at the pump head with the stock 3.8 bar regulator and 1.2 bar of boost. With the 5 bar regulator (6+ bar at the pump head), injector duty cycle usually falls a bit. What pumps do you have?

 

I am not sure what FPR Todd is installing for my setup but is using twin in tank 044 pumps. I guess I was caught up in the numbers, I should have clarified that I am not actually having an issue, just more of observation for those that are in fact running a 5bar fpr.

Earl, glad you brought up injector duty cycle, I guess that is the safety in this.

 

if you are running a one to one fpr you will have a problem..Unless you tune is mapped for this..