[bobcat]

Originally Posted by pigapumbu

Hi Bob,

I am still waiting to hear what a 97RON can or can't do for a car thats been modified. As far as I am aware, its good to use a higher RON which is mostly to deal with detonation. The language as told to me years back is that the internal engine has hot spots and cheap quality fuel or in this case, lower RON are prone to igniting before the spark goes (full compression). So to prevent this, a higher RON is used which helps. My thinking and correct me if I am wrong since I am in no way technical but curious, for cars that have been modified and trying to squeeze the last bhp out of it (within parameters of not causing a blowup), one should then use a higher octane. Something Georgey Dee mentioned.

By giving the car engine the "right" juice the ECU learns, then adjusts ignition etc to maximise what it is being fed. Give it crap, BHP is down as ECU has to readjust to what it has to work with. Thats my take on it I would like to know more if I am mistaken. Please do explain further why you claim what georgey Dee wrote is wrong .. all of it.

cheers.



I must be missing something here. You say, ECU won't lean out the fueling yet a paragraph down say, ECu can inject LESS fuel for same torque because of higher RON.

Sounds like a different way of saying the same thing George penned down.

"As for a standard car,,,,, well the ECU does 'learn' what fuel your using, thats why some companies claim that you use less fuel on super therfore saving money,,,,HHMMM.

Your T5 will after 10 miles of driving learn that super is in it and wind off the fuel... The difference being that if you need more it's there in the form of increased octane."

Awaiting your explanation on this. Thanks

cheer

the ecu wont lean out the fueling thats the point, you get more torque from less air and fuel (thus the same fueling) from greater ignition advance.

for an extreme example of how ignition timing affects torque read up on how antilag works.

higher octance fuel allows higher cyl pressure, thats all!!!!!!!!!!!!!!!!!!!!!