Did i screw it up





schmud0811

Registered
um yesterday i pulled up to the wrong pump by accident stuck the credit card in it and it said 100 octaine well this is the first and hope last time it costs me to 14 bucks to fill up my tank went riding with snyder bike seemed allitle snappier and the gas millage took a drop to 24mpg im just curious if i hurt the bike any....also i was wondering can u run pump gas 91 octane with a 13.1 compression? :hammerhead:
 

Bosch_232

Registered
I am not an expert or a mechanic, but I've asked around regarding octane in the past, and my understanding is that the octane number is not a measure of volatility or power-potential of the fuel (common misconception), but instead is a measure of that particular fuel blend's resistence to ping (also known as detonation).  The octane recommendation by a manufacturer is determined somewhat by the compression ratio of that engine's design. I'm sure there are other factors involved too.

Certainly someone with more knowlege than I can chime in and supplement (or correct) my answer, but my feeling is that the most damage you did was to your wallet.  
wow.gif
 

MET

The Watcher
Registered
Well running it did not hurt the bike, however it is a waste if you are running stock. you do not need more that 87 in most areas. You start going Turbo etc. then an increase in rating is needed. this has been a long debate and proven. if you see you are getting run on or pinging then move up to a 89 etc.
 

schmud0811

Registered
thanx but do u need to use high octain with 13.1 ?? i was thinkin about the 13.1 pistons new head gasket those heavy duty bolt things ,dont know the name of em the ones that hold the engine together and a dry nos kit..by nx? or should i stay with stock compression with nos?
 

MET

The Watcher
Registered
Most likely you would go to a stronger octane (above the 87), but know where near 100.
 

schmud0811

Registered
thanx ninja i allways put 91 in my bike.......but i appreciate the info but do u know if u can run 13.1 with nos?? come on it seems like an cheap easy hp mod.....well semi cheap high compression nos and all the gizzmos for around 3 gs
 

jmasin

Registered
I'm no expert, but I wouldn't run low octane with 13:1.

Bikes are high compression, and run hot. That's a recipe for ping and detonation with low octane gas. The 100 will not help if it isn't needed, but it will take away some power.

Whoever said it above was partially right, the octane rating is mainly a way to reduce or avoid detonation, but can affect power as well.

The lower the octane, the more explosive the fuel will be. So, for a given engine (compression, stroke etc.) the lower the octane the higher the power; however, if compression is high enough, the heat and compression can cause pre-ignition, and instead of a controlled burn wave front, you will get small explosions (ping). If the entire mixture explodes, you will get detonation, which can quickly kill any kind of piston.

You want to run high enough octane that you avoid ping, but any higher won't get you anywhere and you may end up losing power.

I laugh when people put 93 or similar in their naturally aspirated, low compression truck, thinking it will 'clean out the engine'. Its the opposite, 87 will burn hotter, and will do a better job cleaning (now that all gas grades have detergent additives).

Hope this helps, sorry its so long.
 

race24x

Registered
I was a mechanic for GM for 8 years the computer in a car adjusts the timing with a knock sensor etc to keep the timing as advanced as it can without knock and the farther the timing is advanced the more power you can make so the better the fuel octane the more the timing advance you can get hence more power Does the Busa work the same way do you need a PCII to take advantage of a higher octane fuel etc
 

jmasin

Registered
Race,

I don't think the Busa has knock sensors (hence no Knock Retard).

My vette, which you may know, loves to pull out timing, even with 93 octane.
 



Latest Bikes

Forum statistics

Threads
172,209
Messages
3,079,321
Members
47,401
Latest member
Jspence
Top