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Discussion Starter #1
im trying to tap the EGT probe in my manifold but dont know which runner to use. anyone know which cylinder runs the hottest on our cars? i know every engine has a cylinder that runs a bit hotter than the rest.
thanks.
 

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Podiatrist
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vahe said:
im trying to tap the EGT probe in my manifold but dont know which runner to use. anyone know which cylinder runs the hottest on our cars? i know every engine has a cylinder that runs a bit hotter than the rest.
thanks.
I'm gonna guess the one that's the furthest back towards the rear of the car...but then again I've never even opened up my hood.
 

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I've found it is best to use number 6. Since number 6 is sandwiched between the bell housing of the tranny and the the rest of the cylinders it tends to be the hottest. Number 6 is also farthest from the water pump, while I've never done any conclusive test to determine that it runs any hotter then the rest, general logic says it should be hotter.

Jeff

vahe said:
im trying to tap the EGT probe in my manifold but dont know which runner to use. anyone know which cylinder runs the hottest on our cars? i know every engine has a cylinder that runs a bit hotter than the rest.
thanks.
 

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TBKO said:
I've found it is best to use number 6. Since number 6 is sandwiched between the bell housing of the tranny and the the rest of the cylinders it tends to be the hottest. Number 6 is also farthest from the water pump, while I've never done any conclusive test to determine that it runs any hotter then the rest, general logic says it should be hotter.

Jeff

vahe said:
im trying to tap the EGT probe in my manifold but dont know which runner to use. anyone know which cylinder runs the hottest on our cars? i know every engine has a cylinder that runs a bit hotter than the rest.
thanks.
That's where most of the Supra guys put theirs from what I understand. GTE told me the same thing, so that's where I put mine. About 3" out from the #6 port or so.

Kane
 

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This is true, cyl#6 is the winner. If you are tuning strictly with EGTs, forget it. But if you use it in conjunction with a wideband unit, you cannot go wrong. It'll really help when tuning the ignition map for optimum timing.
 

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trekster said:
This is true, cyl#6 is the winner. If you are tuning strictly with EGTs, forget it. But if you use it in conjunction with a wideband unit, you cannot go wrong. It'll really help when tuning the ignition map for optimum timing.
you just defined my setup. I have a permanent mounted wideband and I can't tell you how usefull it is. I'd never go without it again. And worth every penny.

aubie, the further away from the exhaust port the more inacurate the temps are.
 

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Aubie83 said:
Is it okay to tap on the downpipe? This where I got told?
Well, with the cast iron log manifold for your turbo setup, you pretty much HAVE to tap in the downpipe, immediately after the turbine. You will get pretty accurate readings there, as the manifold runners are very short and there is not a tremendous amount of heat lost between the cylinders and the egt sensor. It will still be about 10" from the engine, but will be a fairly good reading.

-Chris
 

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doublins said:
Aubie83 said:
Is it okay to tap on the downpipe? This where I got told?
Well, with the cast iron log manifold for your turbo setup, you pretty much HAVE to tap in the downpipe, immediately after the turbine. You will get pretty accurate readings there, as the manifold runners are very short and there is not a tremendous amount of heat lost between the cylinders and the egt sensor. It will still be about 10" from the engine, but will be a fairly good reading.

-Chris
This is true, but you loose some heat after the turbo, just a little. Lucky for me I have a drill press. Drilling and tapping the hole was easy as pie :wink: .

Kane
 

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Discussion Starter #10
thanks guys. i will tap on the number 6. unfortunately i dont have a wideband. all im using is a a/f meter. i know they look a little wacky with the numbers jumping around but it is accurate at full throttle. thanks for the help fellas.
vahe
 
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