Community Forums

ninos · 03-09-2013, 10:42 PM

Today I did some more work on my Rv, egt gauge and a primer pump for the fuel system, the pump I must say its nice and it makes fuel filters changing a lot easier and no mess, the gauge still not finished. What do you guys think of the spot where I put the probe the gauge?

Click image for larger version

Name: image-2709180450.jpg
Views: 233
Size: 481.6 KB
ID: 34677

Click image for larger version

Name: image-97118373.jpg
Views: 245
Size: 439.5 KB
ID: 34678

jauguston · 03-10-2013, 05:24 PM

For a EGT reading that has any meaning the probe should be pre-turbo.

Jim

stuhly · 03-10-2013, 06:27 PM

Post turbo will generally be about 300 degrees cooler than pre turbo.

jauguston · 03-10-2013, 06:34 PM

Any post turbo temperature reduction numbers are just a guess.

1ciderdog · 03-10-2013, 06:45 PM

Yes, post turbo could be considered a guess but if you run internet searches there seems to be strong agreement 300 to 350 is a good number for the difference between pre and post turbo.

wb7auk · 03-10-2013, 06:51 PM

And EGT probes placed any distant from the cylinder/s is not accurate.

ninos · 03-10-2013, 07:14 PM

But if you look at a cat engine with egt gauge from factory they all have it after the turbo, and another reason I did it after because I feel like at the manifold the reading was going to be based on one cylinder, I know they should all run the same but I chose to to do it after turbo. Doesn't mean that I'm correct.

stuhly · 03-10-2013, 07:38 PM

Its your engine, do it anyway that yanks your crank.

wb7auk · 03-10-2013, 07:45 PM

Just sent request to my Cat contacts lets see what they say.

jauguston · 03-11-2013, 10:49 AM

Cat does not use a exhaust pyrometer input to the ECM.

ninos · 03-11-2013, 03:58 PM

Quote:

Originally Posted by jauguston

Cat does not use a exhaust pyrometer input to the ECM.

I never said that cat uses a pyrometer input to the ECM, I did say that the cat engines that have a pyrometer from factory with a gauge in the dash the probe is after turbo.

jauguston · 03-11-2013, 05:09 PM

I must have misunderstood what you were trying to say. Cat does not install pyrometers. If you are refering to pyrometers installed in a motorhome it would have been installed by the chassis builder just like all the other gauges not Cat.

Jim

ninos · 03-11-2013, 07:32 PM

I'm not saying cat engines on motor homes there are cat engines in trucks like a friend of mine as a c15 engine with a pyrometer and it is after the turbo, and that came from the dealer with it, maybe it was put in by peterbilt but what ever it was they can't be so wrong putting them in the wrong spot and those engines are pushed to the absolutly extreme very often, and not to mention the probe is about 12" after the turbo on the downpipe. Joe

Sonnydale · 03-11-2013, 07:44 PM

Good job.

I agree with others that you want it before the turbo preferably close to the flange(to be perfect), but the thing here is for you to see when something goes wrong. So if you get your baseline temp then this is what you compare it to. You will see when something goes wrong either way.