cshiflet

Just got most of my gauges done, still dont have the pyro in. These are my FP numbers

Idle - 12 PSI
Crusing - 9 - 10 PSI
WOT - 8 PSI

Do these numbers sound a little low?
Also I talked to a cummins tech, he said that cummins recomends putting the probe post turbo, from what I have read on here most people say pre turbo. Let me know what you think.

Clay

msing

I had my pyro post turbo moved it pre turbo seen 200 deg. increse. Cummins shop here told me same thing but I like running pre better more responsive. I do not know about the fuel pres I run a 12 valve sorry

Shovelhead

They are a little on the low side.
Less than 8 PSI is not good at any time.
Is that with the engine up to operating temps?

I noticed lately that my readings seem to run about 1-2 psi low until the engine warms up.

dodgediesel4x4

FP numbers sound good to me. I'd go w/ the pre turbo egt setup. Thats what I have, as most of the members on this site.

amartinson

I think the Cummins techs are using the cautious approach because of the "what if" factor.

The "what if" is "what if the probe breaks off and goes through the turbo". I'm sure this has happened to someone, somewhere, but it is not common.

Stick with pre-turbo IMO. It is definately more accurate.

Shovelhead

My normal readings are 15 psi idle , 13 psi cruise @ 2000 rpm, and 10-11 psi @ WOT.

I'd go Pre-turbo for the pyro probe for the best reading.

cshiflet

What is the advantages/disadvantages of going post vs. pre and the other way around?

phox_mulder

Pre turbo is reading right at the exhaust manifold, as close to the cylinders as you can get
(unless you put a probe at the exhaust valve of each cylinder).
You get quick updates as to how hot things are.

Post turbo is obviously after the turbo,
and a lot of cooling can happen by the time the probe sees the exhaust gasses.
Readings can vary from 200-500 degrees difference post to pre,
depending on how hard the engine is working,
and can be slow updating.

Pre-turbo you run the very small risk of the probe breaking off and getting stuck in the turbo,
causing damage, or chips from the drilling and tapping getting stuck in the turbo,
again, very very small risk.

Post turbo you don't have any of these risks, which is why engine manufacturers say to put it post.

Mine is pre-turbo, and I'm not worried at all.


phox

cshiflet

Thanks for all the replies, I just have to build the nerve to start drilling

Kyle Graham

No they look about average