ayau
Senior Member
How can you validate it’s not knocking on 91? Did you run the Hondata factory map and log knock and timing?I can promise you with every fibre of my body that there is NOT knock on a factory stock FK8 when using the fuel octane it is specifically designed for (91). How knock works on the FK8 is documented over at the Civicx forums.
Essentially the Bosch ECU will retard timing from knock and forget everything when you take your foot of the gas and repeat. The factory tune is ready for ethanol. Honda would not sell a car that cannot be fuelled in the continent in 99% of stations. I don't have the exact laws but I'm 100% positive is federally mandated to accept ethanol.
I’m aware of how the Bosch ECU works. I have experience tuning my own FK8.
Never said factory tune doesn’t work with ethanol. I was implying that the Bosch ECU more than likely is using a universal map because it’s tuned on no ethanol. Other countries don’t use ethanol as much as the US. The ECU runs full time closed loop AF. Any change in fuel will be automatically adjusted by the fuel trims.
The speculation is that the fk8 is rated higher in other countries is because they have access to higher octane. The US rating is based on 91, which is what’s commonly available. So if you use 93, you’ll get the last few HP because the engine isn’t knocking.
Sponsored