5 replies to this topic

[MikeA]

I wonder if anyone might be aware of what the target EGT, or EGT RANGE, for a/any modern F1-engine, assuming they all would burn the same fuel and air?

BR

Mike

[tak]

Exhaust gas temperatures in a 4 stroke piston engine would not be expected to exceed 1000 C or 1700F. Even temperatures that high would indicate lean mixtures and or pre-ignition.

Keep in mind that this is a "temperature average". On a four stroke engine, the exhaust valve is only open 25% to 33% of the time depending on valve overlap. Since there is valve overlap (both intake and exhaust valves open at the same time), some intake charge will go into the exhaust (cooling it). Also remember that temperature falls very quickly as it gets farther from the exhaust port (the exhaust gas is expanding and cooling). So there really is no hard answer.

I would suggest consulting some combustion text books, or at a minimum, check out the "Bosch automotive handbook".

[MikeA]

"Exhaust gas temperatures in a 4 stroke piston engine would not be expected to exceed 1000 C or 1700F. Even temperatures that high would indicate lean mixtures and or pre-ignition."

Ok, sounds reasonable, in general.
But my intent of my question was more specific;
What target EGT (or probably the target EGT range) might the best modern F1-engines have?

And in order to be further more detailed; under these three cases:

1) During "extreme" qualifying, during normal/std temp/pressure&humidity? I.e. when only the very max performance with a short/needed expected longevity, is a issue?

2) During a race and normal phase, during normal/std temp/pressure&humidity? I.e. max performance under "expected longevity" of a race distance.

3) During a race, under a allowed extremely low fuel consumption condidtion during normal/std temp/pressure&humidity; for example when Panis won Monaco a few years ago without any refuelling, i.e. under a absolutely lean fuel consumption, still with a "expected longevity" of a race distance.

All above engine/s assumes burning the same fuel and air, i.e. engines feed with a well-controlled and uniform "induction charge".
These three different (I suspect) EGT:s might give the a (allowed) EGT-range?

"Keep in mind that this is a "temperature average". On a four stroke engine, the exhaust valve is only open 25% to 33% of the time depending on valve overlap. Since there is valve overlap (both intake and exhaust valves open at the same time), some intake charge will go into the exhaust (cooling it)."

Ok, but in a extremely well-spec'd engine, used WITH-IN the very defined power-band, I guess that the possible coolingeffect via a possible uncombusted (to any degree) "intake charge" entering the exhaust (i.e. meeting with a EGT-probe...) during overlap may be quite low?

"Also remember that temperature falls very quickly as it gets farther from the exhaust port (the exhaust gas is expanding and cooling)."

Yes, but in order to view a "true" EGT-value I assume we measure the EGT in a standardized manner and close to the "source"?

BR

Mike

[tak]

Mike--
Good questions all, and ones I cannot answer. I am not aware of any SAE or ISO standards (also note it's not my field!)on measuring EGT--I believe it is up to the experimenter to calibrate their system. The ideal EGT is the one the Dyno tells you makes the most power without damaging your engine.

[MikeA]

tak:

"Good questions all, and ones I cannot answer."

Ok. Thanks for your reply, again.

These EGT-rangenumbers seems to be hard to find; I have yet got either no replies or "Sorry, don't know"-replies?

I am aware of the fact that a unusual EGT-number might reveal something to the "competition" but with a both general F1 engine spec as well burning the same general fuel I also expect getting a "general" answer of a typical EGT-range...

"I am not aware of any SAE or ISO standards (also note it's not my field!)on measuring EGT--"

Well, I have failed to find any factual SAE-info, as well.

"I believe it is up to the experimenter to calibrate their system. The ideal EGT is the one the Dyno tells you makes the most power without damaging your engine."

Indeed.
But what might this general and useable range, as per above, be?

BR

Mike

[SlowDrivr]

I'm reading a good by Nikki Lauda ("Formula One: A Turbo Era"), written in '83 or '84 and he quotes 900 C for naturally aspirated engines of the time and 1100 C for the turbo's of the time. I'm guessing that's in race trim.