> -----Original Message----- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Kotsinadelis, > Peter (Peter) > Sent: Thursday, February 03, 2005 1:30 PM > To: [email protected] > Subject: [inbox] EOS OT - Octane and ACURA > > > Chip Louie wrote: > > >Actually the manual for the Acura will state what fuel octane you will > need to gat maximum performance out of the particular engine model and > engine management system. All modern engine management systems will > fall back to a lower engine power output level if lower octane fuels are > used with no problem, just lower power output until the fuel octa>ne is > increased. The engine still runs safely and is not damaged. > ---------------------------------------------------------------------- > Yes and no. Now this I know about. Octane is actually used to delay > combustion. The higher the octane the longer the time for combustion to > take place. This is why when you used the wrong octane (less) or cheap > gas you get knocking, dieseling, and other problems associated with low > octane fuel. > While Acura can state this in an owners manual, I would still hesitate > to use 87 octane long term in a high compression motor (providing the > Acura engine is really a high compression and not a mid-range > compression motor) as there WILL be issues with it. > > Peter K > >
Hi Peter, Actually increasing the octane level is used to delay the onset of detonation or predetonation of fuel in the combustion chamber. Increasing the octane number of gasoline ideally should not delay flame propagation in the combustion chamber, only the point of uncontrolled detonation. Modern combustion chamber designs and materials are much more tolerant of high compression than the older, say 1995 and earlier designs. Almost all high performance combustion chamber/piston designs are capable of between 1-1.5 points higher compression ratio for a given octane number than these older CC designs were capable of suppressing the onset of pre/detonation. I know something about engine management software. I taught Aaron Neumann (one of the principals of the highly regarded company Neuspeed and APS the distribution arm), how to modify the engine management programs in Bosch FI systems over 14 years ago. Even way back then there was already a fall back for low octane fuel in the engine management programs. This subroutine has propagated to even the lowest level of automobile engine sold in the USA due to emissions warranties here in the states. Cheers/Chip * **** ******* *********************************************************** * For list instructions, including unsubscribe, see: * http://www.a1.nl/phomepag/markerink/eos_list.htm ***********************************************************
