Quote:
Originally Posted by JSH
Is exhaust valve temp an HPT PID?
I see people at 390 on stock cams with no overlap, and people discussing valve failures with SOI at 400-440. On big aftermarket cams with overlap, I'm seeing most at 370-380/170-180.
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no PID for that, I mean the exhaust valve temp being cooled by ethanol evaporation by spraying when the exhaust valve is still partially open. I'm not suggesting this is correct or good or accurate. It's just a thought I had about I wonder if it actually does anything or is beneficial. I also wondered if it cooled the cats a little too. I have NO working theory or proof of this thought.
SOI at 400-440 is VERY bad on DI. You're literally dumping raw fuel into the exhaust stroke and probably at some point at WOT you will have a continuous flame from the exhaust tips as the hot exhaust mixed with raw fuel hit oxygen rich air.
360-380 SOI is fine. 160-180 EOI is fine. Fit the spray window in where you minimize spraying fuel out of the exhaust port and minimize spraying too far into the compression stroke.