Pre-turbo or after turbo

[cguthrie]

I was just thinking about what would be better? if i installed the pyrometer pre-turbo or after the turbo? if anyone could tell me what the disadvantages and advantages are of both please do.

 

[Philip]

Most of us prefer to mount preturbo. That way you do not have to allow windage when you are trying to figure the temps out.

 

[boatpuller]

Pre turbo temps are the ones to be concerned about under a load, post turbo temps are more important at shut down, when shutting down the pre temps fall faster than the post temps because of the heat in the turbo.

Personally I have a gauge pre turbo and a Turbo temp monitor post turbo for engine shutdown.

I would put the gauge pre turbo even if I didn't have the shutdown monitor.

My $. 02

Happy Rammin,

Caleb

 

[BushWakr - RIP]

The guys are right on cguthrie, I've run both and now use only pre-turbo. As your boost climbs the error in readings from a post-turbo pyro grows. I ended up getting tired of "doing math" in my head while havin fun.

Just make sure that you are well under 300*F pre-turbo before you shut down and you'll be just fine.



Merry Christmas !!!



Bob.

 

[Old Smoky]

I have heard a few discussions about which side of the manifold is the best to install the probe. The most common is the back, but some say the front. Any thoughts on this?



Mike

 

[formula]

Mike,

Check out this thread. I've been thinking about the same thing.



https://www.turbodieselregister.com/forums/showthread.php?threadid=62080



If you don't have a wastegated exhaust housing on the turbo, then it shouldn't matter if you mount the probe in the front or back section of the exhaust manifold.



Cheers,

Sean

 

[AlK]

The egt on my truck are taken pre-turbo. That way there is no doubt what the temperature is (what you see is what you got) and my coloured Isspro Gauge shows me at a glance in what zone the temps are. (green 0-900, yellow 900-1100, red 1100+)

---

Al

 

[Old Smoky]

Thanks for the link, formula. I wonder why Holset only "gates" one side of the manifold. I have seen other turbos, such as Cat, that gates both sides. This seems like a more efficient method. I think it would maintain a relatively constant temperature, and pressure, across the cylinders. Gating both sides would also allow the pulse manifold to do it's job in spinning the turbine wheel smoothly.



Mike