what are the effects on egts the higher the octane you use?
If you have a car that runs completely smooth and detonation free on pump gas, then race fuel should only lower it a small amount since race fuel burns slower and cooler. My only experience was with a talon that had bolt-ons and it didn’t lower it much.
depends on your situation. if you have a no knock situation on pump gas, and use race gas and no other variables are changed–i.e. boost is same, and no knock is present on pump gas or race gas, then egts should be damn close.
to get full effect of race gas, either more boost should be used (which changes cylinder head temps/pressure), or keep same level of boost, but bump timing. even then, pending your engine and how it reacts, egt’s should change. timing will deffintely effect egts. little bit either way can make a noticeable difference temp wise–doesnt matter what type of fuel is used.
same token, if you had a semi half ass tune on pump gas, and were slight knocking, then race gas is preventing the knock, whihc means ecu is not pulling timing–which means more total timing=different egts…
reason behind this is if you are optimizing the combustion process on a turbo or all motor car, no matter what gas you use you should be in same ballpark egt wise between the 2 fuel types. egt is at it’s peak temp at 14.7-1 a/f
some of what i say above is not true for a nitrous car though-- a nitrous car’s egt’s generally go down when on the spray due to a better combustion process–which means heat that escaped into the exhaust is now being converted to power inside the engine and out to the wheels…