Thread: Thermoguard or VDO EGT gauge

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.

Originally Posted by rangieman

Might of had something to do if you used the supplied thermo probe (too short)

I have had mine fitted to a 300Tdi and Now a Td5 and in both cases i fitted a longer thermo probe with accuate readings and no fluttering

i use a long probe ...

Originally Posted by rangieman

What motor are you running it in?

Originally Posted by rangieman

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

Hi Rangie et al,

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.

Originally Posted by TheEntertainer

Gents,

I can source pyro probes 100mm and longer if need be.

pricing on Pricing

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

can this unit incorporate a low coolant or temperature alarm Jan?

Originally Posted by Leo109

Hi Rangie et al,

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

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 Tdi

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

It works for me

Originally Posted by rangieman

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 Tdi

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

It works for me

Hi Rangie,

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!!