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What motor are you running it in :angel:Quote:
Originally Posted by scott oz
I first used the supplied probe and found it too short to get a accurate reading hence what inc has said;)
From memory i used a 100mm probe in the Tdi and in my Td5 i am using a 150mm probe;)
Gents,
I can source pyro probes 100mm and longer if need be.
pricing on http://www.nata.net.au/
FYI
The Madman EGT unit will set you back around $100 and then you have the standard extras like battery monitoring, running hours and so on.
Cheers
The entertainer
I have had a VDO one for about 10 yrs now on an Isuzu 4BD1 exhaust and can say that it has been very reliable,stable and easy to read.(Circular gauge). It was more expensive than others but I always believe you get what you pay for.
i use a long probe ...Quote:
Originally Posted by rangieman
Quote:
Originally Posted by rangieman
Hi Rangie et al,Quote:
Originally Posted by rangieman
I'm intrigued by why you would ever need a 150mm probe. Where on earth are you putting all that length? (Errr, perhaps I should re-phrase that...)
What I'm getting at is, even if the boss on the pipe wall and probe fittings use up 50 or 60 mm of the insertion length, that still leaves at least 40 mm of probe tip inside the pipe/manifold with just a 100 mm probe. As the sensing element of a thermocouple (the thermoelectric junction) is within a few mm of the tip, the tip needs to be no more than 20 mm inside the pipe wall/vessel to ensure a good measurement.
Any more insertion than this should make no difference to the measurement but will just increase the restriction and turbulence created by the probe (a probe perpendicular to the gas flow is an excellent vortex shedder). Longer than necessary insertion increases the vibration stresses on the probe and might lead to it failing sooner than necessary from vibration or fatigue. My two cents worth...
Ian
The question on probe length, I gather, depends where you fit it. I've read a few posts with some suggesting that using the EGR blanking plate gives a false reading as it exposes the probe directly (to close) to one cylinder. The suggestion has been to tap and drill the manifold just in front of the turbo so you get the temperature as close to the turbo as possible?
Would be interested in any comments?
The Entertainer certainly food for thought. I'm going to have a go at building my own console. I do like the multi function, separate alarm, and rolling or still display. So there may be a few things for sale if I decide to go your way. Very tempted.
can this unit incorporate a low coolant or temperature alarm Jan?Quote:
Originally Posted by TheEntertainer
I used a longer probe to get it closer to the turbo the probe supplied with the unit i bought was only 10mm long (max) and i felt it was getting more of the reading from the mannifold on the Tdi , once the longer probe was fitted i had a more accurate reading on the TdiQuote:
Originally Posted by Leo109
With the Td5 i used a egr blanking plate and used the longer probe to get closer to the turbo
(pic)
You can just see the probe passing the second exh port
https://www.aulro.com/afvb/images/im...2009/03/13.jpg
It works for me ;)
Hi Rangie,Quote:
Originally Posted by rangieman
That's very clever! I've always considered the EGR port on the Td5 to be a bit too biased towards cylinder no. 1 (like 100%!) to be a good location. But I've never considered using a long probe to reach further in like that - genius! And running basically along the axis of the manifold, it should not be too exposed to pulsating vibrations.
Is the EGR port exactly perpendicular to the manifold centre-line? Or do you have to weld the socket onto the EGR plate at just the correct angle to run the probe down the manifold?
Ian.
PS: Now I understand what you do with all that length!!:eek:
Quote:
Originally Posted by scott oz
Hi Scott,
I've had a thermocouple installed into EGR port of my 300Tdi for tha last 7 years. I also installed another probe into the cylinder no.1 branch a few years ago and recorded both measurements on a datalogger. While the no.1 cylinder probe reacted a little more quickly than the EGR port probe, both recorded very similar maxima at high load (within a couple of degrees).
IMO, the EGR 'pocket' provides a better measurement related to the metal surface temperatures inside the manifold, turbo housing and the turbine blade tips - and this is, afterall, what we're trying to detect with EGT measurement.
However, what you say about EGR port being 'biased' is true. The 300Tdi manifold is in fact a 'split-pulse' design, where the 1-4 and 2-3 cylinder flows are kept seperate until inside the turbo housing (this is, I believe, unusual for a 4 cylinder design). I can't quite recall now without looking at one again, but I think the EGR port is in the cylinders' 1-4 branch.
But, again IMO, I still think the EGR 'pocket' gives a very relevant EGT measurement. This is based, among other things, on the condition of my cylinder head faces and piston crowns when I did a pre-emptive head gasket change at 272,000km recently. I've generally kept to a 720 C limit in the last 7 years (but with the odd excursion to 733 or so...) and the piston crowns were perfect and the head surface showed just the tiniest sign of heat 'ripple' adjacent to the injector streams.
Hope this helps.
Ian