Thread: EGT sensor - upsream or downstream of turbo?

Mine is upstream (though not VDO). The difference, it is argued, between upstream and downstream temperatures can be up to 300 degrees. Therefore it seems logical to place it upstream where the operator can observe the temperatures entering the turbocharger.

I'd be sticking it upstream.

Definitely upstream. Downstream is a guessing game.

I imagine VDO's reason to put it downstream is driven by their lawyers and dodgy installers putting things through the turbo.

mines been in both locations (vdo) and its spot on 200deg, by the gauge cooler down stream.
the only reason i now have it b4 the turbo is i got rid of the egr system and had an easy spot to fit the probe, and i didnt have another nipple to weld to the new 3'' dump pipe.

cheers phil

Downstream, all heavy trucks have the pyrometer fitted downstream where you are taking the temperature of the spent exhaust gases exiting the turbocharger. a driving aid, you back off the throttle to where you are getting the same performance on a smaller throttle opening, injecting less fuel to be still burning in the exhaust system. Now try to convince truck drivers of this.

Originally Posted by discowhite

mines been in both locations (vdo) and its spot on 200deg, by the gauge cooler down stream.

What boost and EGT range is that at?

Originally Posted by Brian Hjelm

Downstream, all heavy trucks have the pyrometer fitted downstream where you are taking the temperature of the spent exhaust gases exiting the turbocharger. a driving aid, you back off the throttle to where you are getting the same performance on a smaller throttle opening, injecting less fuel to be still burning in the exhaust system. Now try to convince truck drivers of this.

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

Originally Posted by joel_nicholson

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

Yes, but it doesn't account for the temp drop across the turbo. Post turbo temps aren't much good for gauging engine meltdown, but they are a little better for guessing how much heat you're pumping away.

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