Thread: Pyrometer in a TD5 defender

Dougal

Don't challenge an unarmed man to a battle of wits...

If that's what he wants to think let him.

Go Dougal !!!

Equalizer-- we have a few very knowledgeable posters on this forum, Dougal being the Turbo Guru. Listen & learn mate..

Let's agree then that the best location for the probe is in the manifold then. My probe is in the dump pipe at the moment but eventually I will relocate it to the manifold. Probably at the same time I fit a VNT. By the way, the most ive ever gone is around 450 degrees C. That's on a big climb with the van on like Bulli pass or the climb out of Byron Bay southbound. Every time a change down and a drop in speed reigns in the temp quicksmart. When towing I drive by the pyro and boost gauges.
Regards
Robbo

Originally Posted by Dougal

Your 100 degree drop is fiction. That's the problem. It can be up to 300c. That's the problem.

Originally Posted by strangy

Agreed and proven with the TD5's here boasting identical map, boost and IC.
The only difference was probe location.
The EGT post turbo was more the 200 degree different.

650 post turbo is guaranteed approaching 900 pre turbo.

I've seen differences of up to 500 degrees. (granted, not a TD5 though - still domestic vehicle).
Another problem I've noted too, is that a post turbo reading can fluctuate quite wildly.

A Post Turbo installation just makes no sense, unless it's physically impossible for you to do otherwise. In which case you need to take your readings with a pinch of salt.

You dont sound witty just insulting. Try to look at it like this one location measures inlet turbo temp one measures outlet turbo temps.you can work with either one most industrial machinery I've worked on have post some stationary constant load machines take a reading in front of each pot, the latest liebherr cranes ( which run Mercedes engines) I drive, have them post turbo I'm sure the entire Mercedes engineers aren't wrong are they. not one location is absolutely the only correct one. Even in manifold placement if one probe is placed further away from compression chamber it will read slightly different.

Originally Posted by Equalizer

You dont sound witty just insulting.

Well bloody listen to the advice given.

Originally Posted by Equalizer

You dont sound witty just insulting. Try to look at it like this one location measures inlet turbo temp one measures outlet turbo temps.you can work with either one most industrial machinery I've worked on have post some stationary constant load machines take a reading in front of each pot, the latest liebherr cranes ( which run Mercedes engines) I drive, have them post turbo I'm sure the entire Mercedes engineers aren't wrong are they. not one location is absolutely the only correct one. Even in manifold placement if one probe is placed further away from compression chamber it will read slightly different.

The mercedes engineers are most interested in the exhaust temp headed into the exhaust filters. Those probes are not fitted to monitor safe operating temps, the engine is already running a constrained A/F ratio which they know is safe.

You must understand the application before you can apply it to a new situation.
Measuring EGT on a tuned automotive engine is very different to monitoring stationary industrials.

Thats right advice/opinion not gospel. not just Mercedes most of our trucks run post and the drivers are told to drive to them the turbo timers are also hooked up to egts. Not saying you 're /wrong in manifold but neither is post turbo wrong just different. On mine td5 I work to 650 post if it was in manifold I would work to maybe 900. Whats so hard with that.