I have a few questions about setting up injector flow rates when using a BR FPR. I'm also hoping that someone can explain the theory of how this works for me.
This is what I have found, but am not sure if it is correct.
Set the fuel pressure "base" with the regulator open to atmosphere.
Use the injector.xls that is floating around to calculate flow rate. Take the number from the 0 kpa cell and use this across the whole injector table.

I set the fuel pressure as described, then hook the reference up to the intake and of course the fuel pressure drops about 15 psi due to the vacuum in the manifold.
The way things are set now, fuel pressure will ramp up to the 58 psi i set it to as it goes from vacuum to atmos. pressure in the manifold, then it will raise up from there depending on boost level.

Is the way I have this set up correct? Or should the regulator be referenced somewhere in front of the intake where it will only see boost?

TIA,

Craig

 

leave it like that... a nice plus is easier idle and decel with big injectors

 

What about the injector flow rate? Use the 0 kpa value for the 58 psi I set it to at atmosphere in the entire table?

 

Flow rate with a manifold referenced regulator will be the same for all points. Reason being is that you have a constant pressure differential now (which helps significantly for boost tuning). Since there is a consistent difference of 58psi between the rail pressure and intake manifold pressure, the flow of the injectors will be constant.

 

On my turbo setup with 60# injectors and BR-FPR, I set the IFR table like normal and i never had any of the complaints that everyone else seems to have with big injectors.

 

That makes sense, thank you. I wasn;t thinking about the differential between the rail pressure and the manifold pressure.

 

That is one of the big pluses with a boost referenced fuel system. You don't have to guess and recaculate the IFR table. Not having to screw with the IFR makes the VE table a lot smoother.

 

Research and you shall recieve 😁 will be trying this out for one of my first tuning projects on my car. Car runs, but it needs to be leaned out a smidge. Running so rich now that it is litterally killing power now. The original tune for the rear mount was using stock fpr with 60lbs injectors, not the turbo is up front, and now is boost referenced fpr, so I now have my first task with my new hptuner mvpi2.

 

Here's hoping it all works out!