So let me start by saying my car is consistent and predictable. Wondering if anyone is seeing fuel pressure variations like this. Pump is an APD internal bypass belt drive on alcohol.

no, where is sensor located

Dennis

The location of the sender unit in the fuel system and how it's mounted can have huge effects on your data logger graphs and all can be just fine with regards to performance.

Stay away from rigid mounting and locating it too close to the carb bowls.

Thanks for the replies. It's currently mounted in the fuel log near the inlet because that's where the vnet cable reached. My plan was to remote mount the sensor and get my pressure reading from the plugged end of the log.

thejagged lines may be from mounting but the difference in fuel pressure makes me think the pypass is not working properly.smoothing would make it look better but with too much dff.my suggestion is use a regulator at end of log with a return and disable the internal.

Random things to add to the mix.
Mounting the sensor on the end of a log can also give funky readings. Picture what happens when a water hose stream hits a wall straight on.

How much of a jump are those spikes? Lbs or tenths? A little smoothing might make it more visually palpable.

It is possible depending on your sampling settings to pick up the pulsation of the pump as the gears/slots pass the outlet hole. Ain't technology grand?

Runs great and consistent. Much ado over not much?

quote:

Originally posted by Dave Koehler:
Random things to add to the mix.
Mounting the sensor on the end of a log can also give funky readings. Picture what happens when a water hose stream hits a wall straight on.



?

Dave

I agree with you, it's a bad location! Helped a racer with this exact issue last year.