tripplewhiskeysip

I need to check if my cats are clogged, but the gages prices are ridiculous ~$100+

I am thinking of using a fuel pressure gage ($14)
http://www.harborfreight.com/fuel-pu...ter-93547.html

Copper hose - to disspate the heat

A hose barb screwed into an M18-1.5 cap so the end fits into an O2 Sensor plug




Do you guys think this will work? Because I havnt done or purchased any of it yet.

jimmyblue

iTrader: (11)

You can get steel compression or flare fittings, a
brake line flare to NPT adaptor and a pipe tap ought
to be fine. Doubt copper would be hurt either. Give
some thought to how you'll plug it once done, put
the hole where it's not going to stress-crack some
thin wall.

I have stick-welded O2 sensor bungs to nodular iron
exhaust manifolds in the past, no prob; you could do
the same with an iron pipe union, cut down, and
have a decently sealable port that has plenty of
adaptor possibilities.

1fastpickup

I've got a buddy that runs one on a turbo race car. Drilled and tapped with pipe thread. NPT to compression fitting is screwed into that and copper line to a cheapo tire pressure gauge that has a max hold on it. So after a run you can see was max back pressure was.

RockinWs6

Proper way to test it is to remove the AIR check valves and use a fitting or large piece of hose over the nipple. I use a old boiler pressure gauge that reads -30-0-+30 works nice and it cost me nothing. You need a gauge that can read low pressures accurately, Reading should stay very low 1-2 psi.

jimmyblue

iTrader: (11)

I've actually been wanting to do something like this,
but plumb it to a spare MAP sensor with its own +5V
supply so I can log it. The information on (MAP-EAP)
can be used to fit the VE table along the Y-axis (MAP),
according to a paper I read.

Now which point in the exhaust stream is relevant,
is another question, as is pulsed EAP in-the-moment
vs averaged (like, you don't really care what it is,
except when the exhaust valve is open).

usdmholden

Mine is made out of on old O2 sensor, drilled and tapped for a 1/4" pipe thread fitting, which adapt to a 1/4" flare fitting. then there is a few feet of copper tube to dissipate heat and the rest is rubber EFI fuel line. That connects to an old tire pressure gauge made for slicks, which reads 0-15 psi.

What you are doing will probably work just fine. I couldn't get to your HF link, but I'd run a carburetor fuel pressure gauge though, the lower range of readings will give better resolution, and if you have more than 15 psi of back pressure, you definitely have something wrong.

SpeedyMerrickan

What a great idea