I'm going to monitor drive pressure in my compound system. Got a gauge and some metal tubing to coil to dissipate the heat from the manifold fitting to the mechanical gauge. But do I need an inline filter to ensure no soot (diesel) makes it way through the coiled tubing and into the rubber tubing of the gauge - eventually to the gauge itself?

 

I'm no expert on diesel tech, but I would think a filter would dampen the pressure readings and eventually become restrictive to the point the readings are no longer accurate.

Personally I would try it without and inspect the hose after a few full boost runs to see if their is any build up of soot.

 

I was thinking the same. But I'll put the filter a ways upstream - found a small one - about the size of my thumb. Swagloc makes them. $72. When I blow through it, it feels like the same flow rate as blowing through the 1/4 inch tubing that leads up to it.

 

I use a 10" long piece of stainless tubing to a pressure transducer on gas engines all the time and there is no problem. Plenty of isolation from the heat with the tubing and its a dead flow setup. There is zero flow through the tubing since the threads of the pressure transducer are 100% sealed and the transducer it self is 100% sealed. If your gauge has a small leak it will eventually carbon up and likely malfunction. It's also possible to use MAP sensors to log the pressure if you have ones that will work at the pressures you have.