Oil pressure sensor and data on can bus?

Hello, I would like an oil pressure sensor to the cayman 987.1 . Basically this is just adding the sensor from the 997.1 and adding the wire that -probably- connects to the DME . The 997 DME will send this oil pressure data to the can bus . This is in CAN Antrieb (drive) id 0x441 byte 7. How about the 987 DME software? as the 987 and 997 DME hardware is the same it should be possible to copy the can bus related part of the software into the 987 flash. Anyone has done this or give me some hints. I do have winols and some knowledge from changing maps. Thank you for your help Andreas

The OP data from the 987 canbus just isn’t very useful. I hadn’t thought about it being any better on the 997 but it’s possible I guess. They both use the same IDs for Can Drive. You are better off adding a sensor at the same location on the opposite head or just replacing the oem sensor and running the output to a logger. If you are wanting to get oil pressure data to monitor drops on track, spin on oil filter and sandwich adapter seem to capture the best data.

The pressure sensor position is not important, the orig position is fine. Can bus data comes every 10 ms, roughly each revolution of the crankshaft. From chatgpt: Speed of Pressure Propagation Model: GPT-4 In a car oiling system: I have 2 measuremt points 50 cm apart and connected by a 5mm tube. Let's assume 5 bar pressure and hot oil. How fast will a pressure drop propagate to the other end? Pressure changes in fluids (like oil in your car's system) propagate at the speed of sound in that fluid. The speed of sound in a fluid depends on its bulk modulus (which is a measure of its compressibility) and its density. For common engine oil at operating temperature, the speed of sound is roughly 1400 m/s. So, if you have two measurement points 50 cm apart, a pressure change at one end would propagate to the other end in about: (0.5 meters) / (1400 m/s) = ~0.00036 seconds

Is there a kit with the gauges, sandwich adapter to accept the input for oil pressure and temperature between the oil filter and LN screw on filter adapter plate?

No, not wiring to the DME , the sandwich adapter between the oil filter and the LN screw on plug has screw places for the direct flow of pressure and heat to the gauges that Slakker and other use. At this point, I just am going to install the Hartech sump and use 1 qt more oil along with the 987.1 Motor Sports AOS . I believe this system is better than the LN system using 1 qt over fill as that is my current system. I blew up 2 oem AOS using 3/8 oil fill and not going to use at least 2 qt more oil to that system. This data is captured on ******** 996 engine oil pressure instability.

you know, I like to do things more elegantly, german style. No messing around with adapter plates etc. I wonder if your analog sensors do have 10ms update time . Just replicate the 997 oil sensor circuit and you are then up to the standard of the porsche engineers.. DME is not diffcult, I know how to recalc checksums after code changes. enjoy your cars. Andreas P.S. Once hardware is setup (additional oil pumps in the heads etc (I use TTP pump) just drive your car and don't let you distract by many data.

I have to point out that much of this 996 data around the Hartech oil sump is done with the 996 oil pressure and temp gauges in the dash. However Slakker need the samdwich spacer to fit the data recepticals for data recording. Slakker suggests that the oem data is lacking speed.

Do we have the DME pinout diagram for 987s to see if there's an unused pin for this purpose already there? If there is, I imagine this would be an easy retrofit.

You can research the addition of the oil temp and oil pressure 997 gauges to our dash boards. Its possible but the readout is not connected to a data log, which you need as your eyes cannot follow these gauges real time in high G corners.

You're missing the big point. It's not to keep an eye on while you're racing, that's dumb. It's to make the data available on canbus so that you can log it all with a datalogger (like AIM or something) to review later. No way you'd be able to react fast enough mid-race to save the engine if you lost oil pressure. High RPM and sudden loss of oil pressure, motor is toast in an instant.

Slakker seemed to think the oem oil pressure data could not be used due to its slow data speed, so he went with the sandwich between the oil filter and LN screw on engine receptical. He could then use the right pressure sender for the data recorder.

that is only true of unconstrained fluid, like open water ocean or a large volume of oil. in a pipe with flow, the propagation of a pressure drop is governed by other laws. pressure drop

Just want to pop in and give some more info on the 997.1 Oil Pressure CAN message. Message ID: 0x441 Signal Length: 8 bits Signal position: Byte 6 (AKA starting at bit 48) Unit: bar Scaling Factor: *0.04 Offset: 0 P.S. I can send out the 997.1 CAN information on our 987 development car and see if I can plug in a 997.1 gauge cluster. It won't help you since you're stock ECU , but when the Link G4X becomes available (currently in the final iterations of alpha/beta) it could be an option.

Just install the sensor (combined sensor, it's a 996 part number), pin it in the ecu on the pin where 997.1 has oil pressure sensor, and voila you have oil pressure available on CAN like 997.1 in your 987.1 . I'm using this for the data display I currently develope for 9x7 chassis. CAN PID from previous post looks correct, if I remember right. Have to look again inside the programm to verify..

That's awesome. Where did you elect to install the pressure sensor, and do we have the pinout diagram?

Just search for 997 wiring schematic you will find it on Google. You can use original oil pressure switch location or on the opposite of the engine (blind plug).

@Goingnowherefast great info! I know that oil temp is in byte 5 of PID 0x441 would you know the formula to covert it to Celsius or Fahrenheit on a 987.1 ?

OK, figured it out and giving back to the community: For 9x7.2: PID 0x441 (Hex) The data (x) is in byte 5 (I start counting at 0) Temp (C) = x - 60 Temp (F) = (x – 60) * 9/5 + 32 For 9x7.1: PID 0x441 (Hex) The data (x) is in byte 5 (I start counting at 0) Temp (C) = x * 3/4 - 48 Temp (F) = (x * 3/4 - 48) * 9/5 + 32

@Hatzenbach What did you do to find the PID? What are you using to read the CANbus? I'm just curious, since I work with CANbus a lot in my work (automation engineer so I deal with PLCs, robots, servos, etc).. I have been thinking of using one of my CANbus PLCs to see what it can see...

Also Automation engineer here (PLCs in automotive industry). And mostly as an hobby canbus and obd communication data analytics and capturing. Many of the common data like temp readings and so on is free available if you google it (on forums or blogs). Specific data that is not public, you have to reverse engineer yourself. Things like graphical canbus data analyzer help you find you values. One easy example is rpm, make a specific test run with the car where you ramp up rpm in a specific time, log it with a canbus logger (diy or buy one) and then go through the log from canbus where the value is rising according to it. Also often car manufactures use similar conversions or datatypes (like bitfields for digital states). So it help to take available data's from other cars and compare it. happy reverse engineering!

It's pretty much like @Speedgelb said: But only a few PIDs can be found on the internet, believe me I searched, and everything I found can be found here: CAN PIDs for 997.2 - ******** - Porsche Discussion Forums (you need to read the whole thread). Initially I built my own Arduino based CAN analyzer, but the I found this: . This guy built (and shares in the video) an amazing Python and Arduino based analyzer. And what's the result of all this you ask? Here it is: Replacement for Sport Chrono clock — 997research

Here's one thing that I forgot to mention. So let's say you figured out that RPM is at a certain PID/byte. Now you need to come up with a formula on how to convert the CAN bus readings into actual values. Yes you can rev the car at several different RPM, but you can't trust the analog gauge in your dashboard. Here is where a Durametric comes in: I create a table with the CAN bus readings and the readings from the Durametric and then create a formula. And one more thing: Your measurements will never be 100% accurate. Let's say you come up with a formula, like this: RPM = ( CAN bus readings) * 0.74893. Well it's highly unlikely that the Porsche engineers chose that formula; it's more likely that your measurements are a bit off and the conversion factor is 0.75 instead.