EGT sensor - upsream or downstream of turbo?

Printable View

Show 40 post(s) from this thread on one page

14th December 2007, 06:31 AM
rick130

Quote:

Originally Posted by Wilbur

Thanks all for the replies. Upstream it is!

Now, can anyone tell me please where I can buy a thermocouple? I lost mine, and now have a lonely VDO gauge sitting in the dash doing nothing.

Cheers,

Paul

err, didn't I post a link to someone that can supply a t/couple in your previous thread ? Ian supplies the adapter and t/couple and can even supply a drilled and threaded EGR blanking plate for a 300Tdi if you don't have a tap to do it yourself (I'm lucky I had one on the shelf, not many people do)

If you want a VDO one go to any VDO service agent.
14th December 2007, 01:17 PM
discowhite

Quote:

Originally Posted by Dougal

What boost and EGT range is that at?

thats the differance between the two positions;)
cheers phil
14th December 2007, 01:50 PM
Dougal

Quote:

Originally Posted by discowhite

thats the differance between the two positions;)
cheers phil

Sorry, should have been clearer.
The pressure and temp difference across the turbine varies with both the current boost and the exhaust gas temp.
So what conditions of boost and EGT give your 200 deg drop?
14th December 2007, 02:10 PM
Bigbjorn

Quote:

Originally Posted by joel_nicholson

But when mounted upstream it can still be used as a driving aid in precisely the same way

The principal and virtually only use of a pyrometer is to determine excess fuel still burning in the exhaust tract after the heat energy contained in the hot expanding gases has been used to drive the turbocharger. you can either back off the throttle or get the fuel system adjusted. I repeat, ALL pyrometers in diesel engines used in heavy trucks are installed downstream of the turbocharger.
14th December 2007, 02:14 PM
Dougal

Quote:

Originally Posted by Brian Hjelm

The principal and virtually only use of a pyrometer is to determine excess fuel still burning in the exhaust tract after the heat energy contained in the hot expanding gases has been used to drive the turbocharger.

How exactly does a pyro detect excess fuel still burning in the exhaust?
They can only measure the temperature of the gas at one point.
14th December 2007, 02:23 PM
discowhite

Quote:

Originally Posted by Dougal

Sorry, should have been clearer.
The pressure and temp difference across the turbine varies with both the current boost and the exhaust gas temp.
So what conditions of boost and EGT give your 200 deg drop?

mt white on the F3, same hill same car same speed. after turbo i get 500deg, b4 the turbo i get just under 700deg. thats 5 gear 110kph.
not sure on boos psi? not full throttle bout half, probably 15psi.

note,
ecu upgrade, intercooler, 2.5'' zorst no mufflers.

cheers phil
14th December 2007, 03:54 PM
Dougal

Quote:

Originally Posted by discowhite

mt white on the m5, same hill same car same speed. after turbo i get 500deg, b4 the turbo i get just under 700deg. thats 5 gear 110kph.
not sure on boos psi? not full throttle bout half, probably 15psi.

note,
ecu upgrade, intercooler, 2.5'' zorst no mufflers.

cheers phil

Thanks for that. I've got a second pyro to install downstream, but it's one of those jobs I haven't yet got around to.
14th December 2007, 04:50 PM
Disco_owner

Just a Question regarding the EGT Gauge ,I 've got my Thermogaurd thermocoupler installed Upstream , the Fuel Pump settings are back to Factory settings, originally had the Pump tweeked ( star wheel spring preload and eccentric cone position changed etc ) I found out on a few test runs that I can reach unsafe EGT temp rather quickly even on factory settings , if anyone knows the Berrowra hill Climb on F3 Foot flat to the Floor 15psi boost and still willing to Climb , with a original exhaust and straight through Muffler , I can quite easily reach 600-650 degrees on factory settings , she is definitely not smoking as much as she did before so this would be a good indication on a better fuel burn ,yes/no? but getting back to the Question ,could anyone confirm that this is rather unusual for Temp to reach that level even with Fuel Pump being very conservative ? Any Help would be much appreciated in advance..
14th December 2007, 04:56 PM
Dougal

600-650 isn't an unsafe temp. I've been running my Isuzu up to 800 on the odd occasion. 750 is the point where I back off, but with the lag in the probe it often goes past.
14th December 2007, 05:15 PM
discowhite

Quote:

Originally Posted by Disco_owner

Just a Question regarding the EGT Gauge ,I 've got my Thermogaurd thermocoupler installed Upstream , the Fuel Pump settings are back to Factory settings, originally had the Pump tweeked ( star wheel spring preload and eccentric cone position changed etc ) I found out on a few test runs that I can reach unsafe EGT temp rather quickly even on factory settings , if anyone knows the Berrowra hill Climb on F3 Foot flat to the Floor 15psi boost and still willing to Climb , with a original exhaust and straight through Muffler , I can quite easily reach 600-650 degrees on factory settings , she is definitely not smoking as much as she did before so this would be a good indication on a better fuel burn ,yes/no? but getting back to the Question ,could anyone confirm that this is rather unusual for Temp to reach that level even with Fuel Pump being very conservative ? Any Help would be much appreciated in advance..

thats the mt white bit i use:o
the 90 (all be it worked td5) will pull that at 110 and 20psi and sit on 550deg. with the trailer (450kg) same at 700deg.

so i dont think your temps are anything to worrie about.

cheers phil

Show 40 post(s) from this thread on one page