Hehe.


I didn't know there was such a debate going on over octane ratings.


Funny thing is. I frequent an audio forum with the same kind of debate about speaker cables and weather or not they make a difference. The debates go on for days.... Its funny really..


I guess I'll just have to decide for myself. Doesn't look like theres any real answer here..


I think I'll just stick with the race gas. The bike runs better with it..



Thanks for the link. And I intend to do plenty of searching. Theres just so much to take in at the moment. Just got here today..




Nik

 

so would you recomend dd for the f2 bc im in need of a new can

 

Yes. I would highly recommend it....






Nik

 

How can you tell? That's VERY contradictory to many dyno readouts we've seen, showing high-octane fuels to actually cause a slight drop in HP on most CBRs across the board, including injected ones. . .

 

Short version. It ran better and felt faster... Maybe it was a placebo effect??? I don't think so. But you guys have me wondering... I'm pretty sure I know what I felt. And it felt faster..

But a last. Its almost empty again. So I'm going to put some 87 in it and see if I can tell a difference...



Nik

 

Well. The bike was about on empty. It held three gallons of 87 octane. How much does the tank hold anyway?

I rode the bike around for about an hour... I don't know if I could tell a difference. The bike ran good. Maybe better? Dunno.

I'm going to run the rest of it out and evaluate the performance and then try race gas again. If there is no difference or if pump gas is better. I'll just stick with the pump gas...

So far I have no complaints with it....



Nik

 

Did you read my last post?

I'm giving it a try.. So far it seems like the pump gas is just as good. If not better. But I am going to run the rest of it out before I decide...


And regarding my statement for there being no real answer. It was pertaining to the thread that you linked. It seemed that 50% of the replies were for pump gas and 50% of the other replies were for race gas. I never seen any real proof(dyno sheets). Just people slinging opinions back and forth...

But like I said. I'm giving it a try..




nik

 

Agree with the gas thing. I'm on my 63rd bike now, BMW Master Tech, Honda, Triumph, Ducati, Suzuki, H-D (yuk!) factory-trained. Gas burns in the cylinder at a certain rate. Once the plug fires, the flame front goes from the spark outward at a given rate based upon compression, combustion chamber shape, intake velocity, valve overlap, and fuel chemistry. Gas companies blab on about good, better, best when they talk about 87, 89, 91 octane, and the public thinks the higher number (and higher price) means what they are told: the higher that number, the better the gas.

BULL HOCKEY

Here's the thing: as compression increases, so too does the speed of the flame front on the ignition stroke, given the same fuel. If the flame front speeds up too much, then a burn of a specified duration (like watching an explosion in slo-mo) actually becomes a hazard to your engine. When the plug fires, the piston is still on its way UP! It's not at top-dead center, waiting to be kicked on over by the ignition stroke. Just how far the piston is ahead of the spark is called "advance"- you've heard of ignition advance I'm sure. Here's how it can be a bad thing to have a too-fast burn...

Say your piston is headed up toward the plug. The plug fires. The flame front starts blooming outward from the plug. The piston is still headed on a collision course with the flame front, but at this point the flame (and shockwave) won't hit the piston for a while yet. If your ignition is timed correctly, the flame front will compress and hit the piston only after it has fully developed into an efficient fireball AND the piston is at or just-after top dead center. The piston has momentum and inertia on its side, now, and the flame front will kick the piston on over, turning the crank.

IF, however, your timing is too early, the expanding flame front will slam into the piston while the piston is still on its way up. You know that can't be good. People call this many things, pinging, knocking, whatever, but whatever you all it will hammer your engine to death. The most severe igniton/combustion problem would be pre-ignition, which is the case when compression is so high that the fuel/air mixture in your cylinder lights itself off before the spark plug even fires. In a simple way, that's why a diesel engine has no spark plugs- it's running such high compression that the fuel literally lights on its own.

The way all of this relates to octane is that higher octane slows down the rate that fuel burns. Generally speaking, octane requirements increase as compression increases. This is why Joe Blow putting race gas into his Taurus is a moron. Octane in and of itself does not equal power, doesn't increase efficiency, clean your valves, give you better mileage, none of that. It regulates the rate of combustion on a micro-second scale. You cannot convince Joe Blow that he can be perfectly fine using 87 octane in his car, or even many stock motorcycles. If Honda puts a sticker on the gas cap saying you can use 89, then you can believe Honda. They have to stand behind their engines, so why would they tell you to put the wrong fuel in? Race gas >>might<< make a particular bike respond better (marginally) or give it any number of percieved minor advantages, but it's super-expensive, it's usually leaded (that's all we need), and the benefits never outweighs the cost. If you're not getting over 7,000rpm, one danger I see is the potential for lugging the engine. Just make sure you keep the RPMs up at a decent level. Running an engine at high RPMs doesn't wear it out faster (God I get tired of hearing that), so you can safely and easily bump your RPM cap up a bit. Once you get used to it you're probably going to be doing that on your own anyway.

What's more important to your engine's life is proper warmup. Start it, DO NOT BLIP THE THROTTLE, and let it idle for a couple of minutes from 1500 to 2000 RPM while you fasten your helmet strap and don your gloves. You don't have to wait until the thing's at running temperature to ride off. Ease the choke in as close to idle speed as you can before you engage first to keep from overimpacting your driveline, then just ride EASY until the thing warms up the rest of the way. Speeding up the warmup process by going WHABBA WHABBA WHAAAAABA on the gas hurts your engine and makes you look like a tool.

My fingers hurt, so I'm gonna shut up. The upshot here is: use the lowest octane gas possible while getting reliable performance with no knocking, pinging, or pre-ignition.