would it be safe to run 100 octane on a stock ap1 block without
burning anything?

and would the ECU adjust to it and increase power?

 

Yes, and no.

 

^^^^


plz explain

 

If you don't have the tune, then the car isn't going to use up the 100 octane, no?

And wouldn't 100 octane foul up the cat?

 

It won't produce any more power because with the current compression ratio, 91 octane will suffice without pinging or detonation. The only way to take advantage of 100 octane is to increase the compression ratio, adjust the a/f ratio and adjust ignition timing for more power.

 

You'll gain power if your knock sensor senses knocks and is retarding the timing otherwise it's a waste. Octane reduces the ease of combustion of the fuel.
I'm sure there are other things but I think this would be the main reason to use it.

 

i ran it in my ap1 but didnt notice a difference

 

thanks guys....

that helped a lot

 

100 octane offers no benefit on a OEM ECU unless you are getting knock (premature detonation) at the current octane you are using. If you get knock, the OEM ECU retards the timing, which decreases the power output.

As others have stated, only real reason for using 100 octane is if you increase the compression ratio or increase timing and you start getting knock. 100 octane is more resistant to knock.

 

No. 100 octane is still unleaded fuel.