ok so heres the story. one of my friends has a impreza 2.5L n/a(bone stock). Now he thinks if he runs 94 octane the engine will read this, advance the timing and give him more power. i say no engine can do this. except for retarding the timing when it sees knock. and will this cause him to loose power and maybe even build up more carbon deposites. Oh and it reads the octane rating by advancing the timing and retarding it when it starts to see knock plz tell my friend hes an idiot. plz. or am i

 

hes an idiot. The car is set with base timing, then it sees knock it does retard the timing until it goes away. Now with the wrx, if it sees knock it retards the timing and actually holds it there until it gets manually reset. If that is a feature that ALL subarus have im not sure. Higher octane does not make power however. The higher the octane, the more resistant to detonating, and thats the bottom line.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Tmack &raquo;</TD></TR><TR><TD CLASS="quote">hes an idiot. The car is set with base timing, then it sees knock it does retard the timing until it goes away. Now with the wrx, if it sees knock it retards the timing and actually holds it there until it gets manually reset. If that is a feature that ALL subarus have im not sure. Higher octane does not make power however. The higher the octane, the more resistant to detonating, and thats the bottom line.</TD></TR></TABLE>

it's true that the cars are set with a base timing, however, base timing is usually set with the computer out of the loop. toyotas for example, are set after you jump two pins on a diag. connector bypassing computer control of ignition timing. once the computer is in control, it will advance timing up until the point of detonation, and then retard it slightly until it is gone. it will then advance it slightly and so on going on a see-saw type control back and forth.

this was with the older ignition systems where base timing was adjustable. with all the computer controlled everythings they have now, it's hard even to find out how far a computer will advance the timing past any point.