Exhaust pressure

[Force Fed Mopar]

Those of you measuring the pressure in the exhaust manifold, what are you using?

[Vigo]

Havent done it yet but i figured run a hard line far enough out from the manifold that it's not heat soaking to ridiculously high temps, and then run a high temp hose from there.

[Force Fed Mopar]

Havent done it yet but i figured run a hard line far enough out from the manifold that it's not heat soaking to ridiculously high temps, and then run a high temp hose from there.

Hmm, and run it to a boost gauge? Simple enough, so simple I didn't even think of it lol. I guess close to the turbo inlet is the best place to measure?

[Vigo]

I would think anywhere in the manifold would be pretty close to the same but it might read steadier with less bouncing if you put it right in front of the turbo. You could use a boost gauge but depending on how high your boost level is it might not read high enough. Youd definitely need a 30 psi gauge but something like 40-60 might be better cuz a stock turbo at high boost will probably peg a 30psi gauge in the exhaust.

[BadAssPerformance]

I would put it at the "collector" and yes need a higher psi guage. Years ago when Paul Smith (yes, that Paul Smith that had the quickest van for years) put a pressure tap in the EGT hole he read 60psi in the exhaust manifold with 30psi boost... IIR was an FM E2 turbo, PowerStroke IC

[Force Fed Mopar]

...he read 60psi in the exhaust manifold with 30psi boost... IIR was an FM E2 turbo, PowerStroke IC

That would be a 2:1 pressure ratio, right?

[wallace]

I've used a oil pressure gauge to visually check backpressure. Just use a coil of copper line to get the heat out of it. To log backpressure I used the same coil of copper wire and connected to electrical fuel pressure sending unit with gauge. You add 2 wires that aren't present on the autometer gauge connector to log it if you want to.

[turbovanman²]

I am going to test mine before I put on a header, just to see the change.


That would be a 2:1 pressure ratio, right?

Correct. I think Shadow's setup is close to 1:1 IIRC.

[turboshad]

Here is what I did. The coils will dissipate the heat and then there is no need for high temp line. Remember it isn't flowing air but stagnant pressure so the heat won't be going all the way to the gauge. The green mark on the far left gauge is 30psi so this blur of a video shows 40psi at 28psi of boost on my 10.79 run.

http://i54.photobucket.com/albums/g103/turboshad/93%20Shadow/Exhaust/DSC_3664.jpg


http://www.youtube.com/watch?v=LjhhviiDnzI

[zin]

Hmm, and run it to a boost gauge? Simple enough, so simple I didn't even think of it lol. I guess close to the turbo inlet is the best place to measure?

If you want to log it, you could use the Charge Temp input like has been discussed in regards to logging WB readings, just use a MAP sensor in place of the WB feed...

Mike

[turbovanman²]

If you want to log it, you could use the Charge Temp input like has been discussed in regards to logging WB readings, just use a MAP sensor in place of the WB feed...

Mike

Good idea, I just bought a dual gauge with boost and IAT temps.

[Force Fed Mopar]

Apparently that will require a 4 or 5 bar map...

[Vigo]

I think you could just log the signal from a fuel pressure or oil pressure sender as already mentioned.

[zin]

So long as it is a 3wire, 0-5v sensor it could be logged on that channel.

MAP sensor was just convenient. There are many 0-5v pressure sensors that could work, but they tend to not be laying about the garage.

Mike

[wallace]

So long as it is a 3wire, 0-5v sensor it could be logged on that channel.

MAP sensor was just convenient. There are many 0-5v pressure sensors that could work, but they tend to not be laying about the garage.

Mike

The autometer stuff is 2 wires. Is the third wire the 5v reference?

[turbovanman²]

The autometer stuff is 2 wires. Is the third wire the 5v reference?

One is voltage, one is return, one is ground.

[zin]

What he said!

Mike

[Vigo]

The computer is looking for a voltage signal. 2 wire sensors can't really provide a voltage signal. You'll have a source voltage, the load, and then the ground. The source voltage will stay roughly the same, the load will vary its resistance, and the ground will always read 0 volts. So the varying load will change current, but the computer doesnt read current, it wants to read voltage. So you'd basically need a 3 wire thing unless you're dealing with some kind of component system where 12v goes into the sender but 0-5 goes out to the gauge, then you could tap that line.

[wallace]

Yeah the autometer gauge has a 0-5 volt output with just two wires so no need for the 5v ref.