Hey all. I'm noticing some weird stuff with my temps. If my port temp results are to be believed, then I'm getting some pretty crazy heat soak. Not out of the question, but I'd be somewhat surprised if it's really this bad.

Looking more carefully at the data, there's the two different temperatures -- port temperature and air temperature. AFAIK, the only temp sensor I hooked up was the GM air temp sensor, which I wired to BD09. I assume that's hooked into the Hydra as "port temp", but where might this other temp reading be coming from? I can't find a full pinout for the Hydra anywhere, I only have the one from Jeremy, which doesn't seem to indicate a second air temp sensor anywhere. Any ideas?

 

I have asked Jermy this very question . Apparently the port air temp gets its signal from the GM sensor plus some calculation on the Hydra's part to arrive at a port air temp. Fred

 

So the BD09 GM ATS sensor directly feeds the air temperature, and then the Hydra applies a calculation to get the "port" temp? Or visa-versa?

 

Reading some more about this, it seems to be conflicting all over the net.

Right now, I have a bung drilled into my intake manifold right at the inlet (simple custom short runner log intake manifold), which is about 5" from each port, that the IAT is screwed into. If it's trying to do messy calculations, then it's going to double-account for temperature increases, since the IAT is post-compressor/intercooler.

While it makes sense for MAP-based fuel metering to measure both the MAP and the IAT at the same place, is Hydra trying to do something stupider?