Hatzenbach

I always hated that the sport chrono clock is absolutely useless (unless you have the needed patience to make the stopwatch stop at "9:11" ;-)
About a year ago I did a bit of tinkering and replaced it with a VDO analog clock, following these instructions


Well, yeah that looks better, but is not very useful either.
In order not to bounce off the walls due to Covid-19 shelter in place I needed a new project and came up with this:
The analog water and oil temp gauges in our cars are very inaccurate and on the track my oil temp shows sometimes scary high temperatures.
Well I know the oil gauge is totally off (I checked with my AIM Solo), but it still troubles me.

So how about I replace the sport chrono with an accurate digital oil/water display?
But there are no aftermarket gauges available and the only way to get readings for the oil temp is to tap into the CAN bus (only water temp is available via OBDII).

I did a lot of research and finally decided to build my own CAN bus water/oil gauge from scratch, here is the final result:



It was tricky:
I used an Arduino micro-controller with a CAN-bus shield and a 128x64 pixel OLED display
in the picture you see on the left (under the cables) the CAN bus shield and to the right the Arduino (NodeMCU micro-controller), the black box to the very right is a 12V -> 5V power converter



Here is the 1.3" OLED display in the housing of an old VDO oil temp gauge (that I still had from an abandoned project)
The housing has 52 mm diameter and fits perfectly into the sport-chrono wart.




To get to the CAN bus you need to tap into the wire harness on the left of the fuse panel (the CAN bus plug that goes to the sport chrono clock does not carry the data for water and oil temp - now I finally understand what a CAN bus gateway is for :-)
And the really tricky part is that Porsche does not publish the information that you need to decipher that data on the CAN bus:
You need: the Porsche CAN-Ids, the significant values and the formulas to convert them.
But here I got lucky and found exactly ONE post where someone reverse-engineered it.

Overall less than $100 spent and the whole project probably took me ~20 hours, including programming the Arduino and hacking the VDO oil temp gauge.

What do you guys think? Good? Bad? Ricer?

63mercedes

That's incredible, very cool and extremely useful upgrade.

Ryans Rebel

Excellent work. It would be cool if the text turned red once the temp gets too hot.

workhurts

Very cool. I’d probably tinker with the display till it somehow looked oem.

Hella-Buggin'

Nice Work!
When this Social Distancing this passes, whenever that may be, come over and help me do my car.
I'll feed you dinner and fancy German Beer.

-Mark

Presto

Fantastic work.i think it’s very cool and extremely useful. If you decide to make more I’m definitely a customer. Keep up the good work.

scadams

Nice project. I don't know why Porsche decided to have it only function as a stopwatch. It's a nice looking unit. That being said, I wouldn't mind replacing it with a configurable color AMOLED display.

cwheeler

Love it.

Petza914

That's awesome. I was actually going to swap the SC dash from my wife's car with the non-SC dash in my car so I could install a full function oled gauge. Decided it was too much work and am just going to install the gauge in the top corner of my A-pillar. In addition to oil and water temp, I want to monitor boost and AFR since my car is supercharged.

Great job on yours though - bet you could sell a bunch of these to people with SC cars if you decided to. Programmed and ready to go with the plug and play harness for $400 and you'd be good to go.

KLS

I love it but I knew it was out of my skill set right about here; "I used an Arduino micro-controller with a CAN-bus shield and a 128x64 pixel OLED display"

DocR

I've changed mine to the VDO clock and it's a bit more useful that a non-functioning Chrono, but this is amazing. Great work.

Wayne Smith

Well done. In fact, very well done. You have a side business if you want!!!!!

Wayne Smith

Having a car that I've seen 275 on my oil temp gauge (spirited high load street driving during climbs) I'd be really curious to know how your digital gauge compares to your analog gauge.

FWIW my radiators are clear, my fans are working, in my 100K miles with the car I've not added a drop of oil, oil out = oil in at every 5K mile change, and oil analysis looks good.

So I find myself wondering if I have an overheating problem, a sender problem, a gauge problem, an errant driving technique, or ...

I've been debating adding a third radiator, mostly for concerns with extra heat in the PDK, but would like secondary confirmation that the oil temp is actually that high. So I'm curious how truthful Porsche is with their temp gauges.

Thanks in advance for any data you can supply. And congratulations again on completing a great project.

Hatzenbach

Dude, can't wait, I miss you man!

Hatzenbach

Thank You,

so far on the track I used the AIM Solo to monitor oil and coolant temp. And I calibrated the new gauge against the AIM Solo, so the readings should be identical.
What I saw when comparing the readings from the AIM vs. the analog gauges, was that the analog gauges in my car show up to 20 degree higher than actual.

I have the 3rd radiator and this spring my shop installed a PDK cooling solution (radiator and transmission oil pump) but then shelter in place struck and I haven't been on the track since then.