Fuel/air meter

[landtoy80]

To test my #2 O2 I could hook it up to each and see if they read about the same.
The only problem would be if one of the injectors that feed the #2 exhaust pipe(#2 O2), is dirty or leaking(at 230k I am sure they are not balanced), that would change the A/F for that cyninder which would change the reading from the A/F meter, right?

 

[ppc]

The A/F is not a contant reading. It constantly goes lean to rich. At highway speeds it might be 3 or 4 times a second. I don't think you would see any difference.

 

[landtoy80]

Should I get a digital or non digital meter?

 

[RavenTai]

>is since the turbo "uses" the heat that travels through the exhaust,<
>would it actually decrease the temps over a stock setup? Seems too good to be true,<
>what am I missing?<

I only have a few hours education with turbo's many years ago in college but I am quite familiar with their close relative the air cycle machine, and this does not sound accurate to me,

pressure and temperature are directly proportional double one it doubles the other halve one and the other is also halved (in a contained volume), both temperature and pressure are inversely proportional to volume, double the volume the gas is contained in and temperature and pressure are both halved, cut the volume in half and the pressure and temperature double

the turbine operates on pressure differential and gas flow not temperature differential, the drop in temps across the turbine is a side effect of gas no longer being contained and expanding, the heat did not go anywhere or get “used” it is just more spread out, the pressure was “used” and is now lower that is where the energy to turn the compressor came from

I would think your post turbine temps would be the same or higher than a stock truck (forced induction gives higher combustion temps) and probably very similar to supercharged truck, the very high pre turbine temps are more form the gas not being able to expand into a relatively low pressure exhaust manifold and cool like they would in a supercharged or NA truck,

hope that is accurate for a turbo also

 

[ppc]

[quote author=landtoy80 link=board=2;threadid=13504;start=msg126604#msg126604 date=1080178744]
Should I get a digital or non digital meter?
[/quote]

From my perspective that is just a personal choice, my preference being analog. I was 20 years old before digital watches and clocks came into exsistence and I'm hard to retrain. Even to this day when I see a digital clock I automatically transform the reading to an image in my brain of an analog clock. I perceive the variances better on an analog display as sometimes a digital display keeps changing and doesn't provide a display. This happens with my Fluke multimeter trying to monitor the O2 sensors, or looking at the output of the throttle position sensor as an example. You can't really tell if the readings are smooth or have hot spots.

 

[landtoy80]

I will go ANAL.
I had the same problem when testing my O2 sensor with a digital multimeter. Is there a cheap one that you recommend?

 

[Scamper]

I don't believe you'll get any useful data from either a digital or analog multimeter when measureing the output of the O2 sensors since on a multiport fuel injection system, the cycle times are too quick (like 7 or 8 times per second I think) and the response time for the meters are too long. At best I think you'd get the average voltage, though with the Fluke--mine has a max reading feature--you might be able to read the high voltage level if you catch it right, but I'd be suspicious of the readings.

 

[cruiserdan]

Diesel is indeed cooler. I have a pyrometer on my Dodge/Cummins and It rarely gets above 1,050 degrees. The thermocouple is mounted about 4 inches aft of the exhaust turbine.