Anyone tried differential pressure sensors for fuel pressure?

[rdeis]

Our fuel pressure is supposed to make a 1:1 increase with boost. So it occurs to me that a conventional fuel pressure gauge is hard to read or use while driving-- I can't really set a low limit or high limit that works all the time.

Has anyone tried pairing a fuel pressure sensor with an air pressure sensor so the value always reads as the difference between manifold and fuel pressures?

Seems like that would be constant value that would easily indicate that things are or aren't right in the rail.

 

[steve]

The FPR must track manifold pressure 1:1 not just with boost. Assuming you already have a sensor that reads manifold pressure (like a MAP sensor) and another that reads fuel pressure you could check that the difference between the two always equals the base fuel pressure.

 

[Justin DuBois]

If you have MAP and FP in your logs - it is a good idea to check for correlated increases in pressure. Fuel pressure and manifold pressure should map to each other with a base fuel pressure offset - (42.5 psi) - IE you could assume your manifold pressure is 0 when FP is 42.5psi, same as you can assume your manifold pressure is 20psi when the FP is 62.5psi.

 

[rdeis]

Yes and yes! Please forgive my imprecision...

In addition to post-run log analysis, I'd love to see this on a gauge while driving. A nice gauge can give you a warning light, which is even better, but you have to either combine the MAP and FP sender signals somehow or have a 2-port sender that reports the difference to the gauge.

 

[Justin DuBois]

Yes and yes! Please forgive my imprecision...

In addition to post-run log analysis, I'd love to see this on a gauge while driving. A nice gauge can give you a warning light, which is even better, but you have to either combine the MAP and FP sender signals somehow or have a 2-port sender that reports the difference to the gauge.

Race Capture is a CAN bus enabled device that you could use to map two sensor channels into one for display on a custom gauge. The "dashboard" is completely customizable.

 

[jdxnc]

Depending on the ECU you run, it can be an option to warn if it doesn't follow 1:1, for example I run a Fueltech FT550 and you can set it to throw a warning or safe mode when fuel pressure differential exceeds a set level. A warning light or other simple warning like so would be way more useful than a gauge, while driving you have more important things to watch.