MAP Sensor Plumbing

[skelrad]

The MAP hose bulkhead fitting from Van's has a small restrictor on it (looks like the tubing they send for it is around 3/32" ID). I understand the need for the restrictor, but is there any issue using an adapter to then upsize the tubing to 1/4" ID so it fits the sensor Dynon uses? Is it okay to go from small to large ID like this, or does the restrictor need to be at the tail end of the chain? To make a little more tubing chaos, the PMag port looks like it's in the middle - maybe around 1/8" ID, so I'll also need to find an adapter to branch off of the 1/4" tube and run back out to the PMags for this third size. Yes, I do know I can fork out money to have specialty lines made for all of this on the engine side of the firewall, but I'd rather just use what I have if it's not actually necessary.

 

[RV7 To Go]

No issue going from the small to the large size hose. I did the same on both the 7 and 8 and MAP reads fine. I used a restrictor fitting at the jug and adapted to the larger diameter hose from there to the sensor mounted on the firewall.

 

[TS Flightlines]

No issue going from the small to the large size hose. I did the same on both the 7 and 8 and MAP reads fine. I used a restrictor fitting at the jug and adapted to the larger diameter hose from there to the sensor mounted on the firewall.

Here is how we do it---but we use -3 teflon hose with AN hose ends. YES, you can use rubber or plastic hose. We also use the restrictor at the cylinder (AN823-4R) and an upsized hose end fromt he -3 hose to fit the restrictor fitting. The PMag hose has an ID of +- .125, so our -3 hose end stems work well. A LOT of them flying worldwide.
Tom