Fuel Parallel Lines help
 

Hi guys I hooked up my fuel lines to parallel I split my feed line with a Y fitting going to primary and secondary rail. My return lines are split and going seperate to the the FPR. The thing that im concerned is that my fuel pressure sensor is on my secondary rail will it be accurate when my primary injectors work or will it show the pressure on secondary rail which will be ok since the secondaries will not work?

The whole system is common so regardless of where the sensor is on pre regulator side, it will read the same pressure. What regulator are you using? Can draw a picture of your fuel diagram?

https://cimg8.ibsrv.net/gimg/www.rx7...19c1d452e0.jpg
its a sard fuel regulator
im thinking maybe beacuse its parallel and the lines going to the FPR are not connected maybe the pressure on the primary is different from the secondary when primaries are working

Your fuel pressure location is fine. Its all pressurized and as it relates to the sensor, its just one large cavity. It doesn't know anything Y fittings or multiple rails. All it knows is pressure.

I don't quite understand how you did your parallel set up with a 2 port regulator. Both rails have to feed into the regulator with a common return so you would need a 3rd port unless you merge the 2 rails back into 1 before it goes into the regulator. Your diagram doesn't show the return line.

My return line has a 3rd port on the downside of the FPR just dont have it drawn.
So its ok there is no pressure drop in the primary rail which the sensor doesnt see?

If there will be a pressure drop then the sensor will pick it up regardless of its location. The sensor doesn't know anything about the path of lines or anything else. It doesn't know there are 2 fuel rails. It doesn't know there are 4 or 46 injectors. It doesn't know if there is 1 foot of 100 feet of fuel line. All it knows is the pressure of the cavity in which it is installed. Even if there was an undetected pressure drop, which there won't be, it would be a minute amount. Not enough to matter or make a difference.

If you had an EXTREME build going for some wild power in a competitive setting then the pressure drop MIGHT matter but its not important. Part of the reason to do a parallel set up is so the pressure drop from the secondary is mitigated and even then, so long as your primary and secondaries are close enough it becomes a non issue. The location of your pressure sensor is fine where it is and whatever concern you have can be put to rest.

Thanks man very helpful information.