captdistraction
GrumpyRacer
Since building a motor (and historically even), I've had a lot of problems getting a decent oil pressure gauge reading.
My current setup is two AEM brass 150psi oil pressure transducers/senders, one going to a AEM 150psi analog style gauge, and the other going to a Racecapture Pro MK3 data logger. The analog gauge also has a dedicated 0-5v output that I have going to the RCP logger as well.
What I'm seeing is once the car is out on track and heating up, oil pressure reading on the analog gauge (and what its sending to the RCP) is dropping significantly lap after lap, to the point where it was in the 40's at 7000rpm down a straightaway (very concerning indeed). Oil temps were climbing as well, however the RCP's readout from a similar sender did not show the same drop, and would read 80+psi as expected.
Here's my crayon diagram of how I have this setup:
and here's a data graph showing the drops: (2 laps, and can see the drop by lap 3 getting to be very significant) - this is reflected both in the logger as seen in this graph, and on the gauge face while I was out on track
Here's the RCP sender:
You can see some drop, but its to be expected with oil temps climbing from 220 in lap one, to nearly 290 in lap 3 (cooling is a separate issue, but this was at high altitude on a very hot day testing). I'd park the car after the 3rd lap.
So far, I've done the following:
Swap the sender and the gauge body out
Swap the RCP and Gauge's connections out (so the RCP would read the one sender the gauge was reading the session before)
And the behavior continued (with the difference of the pressure delta in the loop showing up, so in some tests it would show 40psi coming off the pump, but somehow 90psi going into the bearings, making little sense). I believe it has to be a wiring issue, but a quick test with a multimeter didn't show much that would affect the signal. I will order a replacement harness, however I don't think that's going to solve my issue as I couldn't find anything. having replaced each component at least once I'm at a bit of a loss.
There was some discussion around the bernoulli effect and some discussion about how noisy these senders are (which I've since added a 12" line to one to isolate it better from engine vibration). The other is well isolated with the oil filter block. I've not sent this to AEM yet for their opinion, but I don't like seeing oil gauge issues as that just gets in my head and sticks there as motors are expensive, though I believe this to be an obvious false positive.
Its costing me lap time and sleep, has anyone else run into something like this? Is there a better solution (I've been eyeing some compatible senders from bosch, autosport labs, and others that have the same scaling output)?
My current setup is two AEM brass 150psi oil pressure transducers/senders, one going to a AEM 150psi analog style gauge, and the other going to a Racecapture Pro MK3 data logger. The analog gauge also has a dedicated 0-5v output that I have going to the RCP logger as well.
What I'm seeing is once the car is out on track and heating up, oil pressure reading on the analog gauge (and what its sending to the RCP) is dropping significantly lap after lap, to the point where it was in the 40's at 7000rpm down a straightaway (very concerning indeed). Oil temps were climbing as well, however the RCP's readout from a similar sender did not show the same drop, and would read 80+psi as expected.
Here's my crayon diagram of how I have this setup:
and here's a data graph showing the drops: (2 laps, and can see the drop by lap 3 getting to be very significant) - this is reflected both in the logger as seen in this graph, and on the gauge face while I was out on track
Here's the RCP sender:
You can see some drop, but its to be expected with oil temps climbing from 220 in lap one, to nearly 290 in lap 3 (cooling is a separate issue, but this was at high altitude on a very hot day testing). I'd park the car after the 3rd lap.
So far, I've done the following:
Swap the sender and the gauge body out
Swap the RCP and Gauge's connections out (so the RCP would read the one sender the gauge was reading the session before)
And the behavior continued (with the difference of the pressure delta in the loop showing up, so in some tests it would show 40psi coming off the pump, but somehow 90psi going into the bearings, making little sense). I believe it has to be a wiring issue, but a quick test with a multimeter didn't show much that would affect the signal. I will order a replacement harness, however I don't think that's going to solve my issue as I couldn't find anything. having replaced each component at least once I'm at a bit of a loss.
There was some discussion around the bernoulli effect and some discussion about how noisy these senders are (which I've since added a 12" line to one to isolate it better from engine vibration). The other is well isolated with the oil filter block. I've not sent this to AEM yet for their opinion, but I don't like seeing oil gauge issues as that just gets in my head and sticks there as motors are expensive, though I believe this to be an obvious false positive.
Its costing me lap time and sleep, has anyone else run into something like this? Is there a better solution (I've been eyeing some compatible senders from bosch, autosport labs, and others that have the same scaling output)?