Which Octane?

[The Stranger:Me]

CaN, the term you refer to is 'pinking', I believe. Normally caused by too-advanced timing on low(er) octane fuel, when the engine is under load. The answer is either - increase the fuel octane, retard the timing, or best of all, never let the engine labour.
As an aside, I used 91/95/98 at various times in the 1100 - it run fine on any of them, but best on 98. Have only used 95 in the 750 so can't comment there.

Why do you call it pinking?
It is commonly referred to either way, just like duct tape (the silver tape, once used to secure air DUCTS to plenums) and for some strange reason duck tape which is I suppose used to package ducks for transport.
I choose to use pinging as I feel it more accurately describes the sound made when pinging (or pinking if you like) takes place. I mean we all know what a ping sounds like, but only a few or us know what a pink sounds like.

[Steam]

Anyone got a link to a sound file of pinking / pinging?
I'd be interested to hear.

[The_Dover]

it's not a fucking performance issue for christs sake, it's a pre-ignition issue (which may lead to poorer performance, granted).

higher octane fuels require higher compression cos they BURN SLOWER.

[The Stranger:Me]

It's all in the mind. If your engine is not a high comp performance motor then why waste your money on higher octane fuel than you need??

It runs better, bollocks, that's like saying you get pissed quicker on poofy boutiqe beers with a lower alcohol content cos they taste nice and cost more..."it's the designer bubbles..."

load of old toss.

Your comparrison is a bit lame there. Where you to equate low alcohol with low octane and high alcohol with high octane you will see immediately why you should be drinking high octane fuel.

The blackbird is (well was) cheaper to run on 95 and cheaper again to run on 98, so that is why I would "waste" my money. It got better fuel milage on the 95 and 98 in over 40 consecutive tests to the point that dollars expended per 100km were less on the higher octane fuels. Not saying all bikes will produce the same result at all, but maybe it is worth a try.

[The Stranger:Me]

Anyone got a link to a sound file of pinking / pinging?
I'd be interested to hear.

No, but imagine an aluminum piston slapping rapidly in a steel cylinder.

[The_Dover]

No, my comparison was not comparing low alcohol to low octane at all (in fact the reverse). It was an analogy of the misconception that if it costs more it must be better.

As you said yourself the 'bird had a knock sensor, i'd surmise that it adjusted the timing and fuelling accordingly, maybe not.

The people I am getting at are the ones that have no understanding of pre-ignition (pinging, pinking, knocking, burping, farting whatever you call it) and what the octane ratings of fuels actual pertain to.

High Octane is not a measure of the calorific value of a fuel. The only thing which affects a fuels power output is the calorific value of the mixture, not it's octane rating.

[The Stranger:Me]

No, my comparison was not comparing low alcohol to low octane at all (in fact the reverse). It was an analogy of the misconception that if it costs more it must be better.

As you said yourself the 'bird had a knock sensor, i'd surmise that it adjusted the timing and fuelling accordingly, maybe not.

The people I am getting at are the ones that have no understanding of pre-ignition (pinging, pinking, knocking, burping, farting whatever you call it) and what the octane ratings of fuels actual pertain to.

High Octane is not a measure of the calorific value of a fuel. The only thing which affects a fuels power output is the calorific value of the mixture, not it's octane rating.

In one of the previous threads on this subject someone posted a file (pdf I think) which showed that higher octane fuels can and do have a higher calorific value (though if I recall correctly it wasn't termed calorific) will try and find it after work for you.

[Delirium]

I think that's a fairly good explanation of it. Why the fuck would your engine run better on a fuel that is designed to ignite at a higher compression ratio?

It's all in the mind. If your engine is not a high comp performance motor then why waste your money on higher octane fuel than you need??

It runs better, bollocks, that's like saying you get pissed quicker on poofy boutiqe beers with a lower alcohol content cos they taste nice and cost more..."it's the designer bubbles..."

load of old toss.

that quote pretty much sums it up. it is the high compression engines that are 'high preformance' that require high octane feul.
also, if you observe the majority of the quotes on this thread then you'll see that the people that say their bike runs better on 95/98 actually have high performance bikes.

[The Stranger:Me]

that quote pretty much sums it up. it is the high compression engines that are 'high preformance' that require high octane feul.
also, if you observe the majority of the quotes on this thread then you'll see that the people that say their bike runs better on 95/98 actually have high performance bikes.

Exactly.
Take say a 250 pulling 33hp and compare it to say a late model cage engine of say 6 litre pulling 400hp.
The 250 is a high performance engine, not far off of the same HP per litre as the blackbird.

[The_Dover]

so how do they run better?

would someone like to dyno their bike on a tank of 91, tank of 95 and tank of 98??

[gijoe1313]

You mean after all this time, there are still some issues which are a black art? I woulda thunk that this sort of thing would have been cleared up by now! Surprising to know that this technical boffin thing is still keeping riders in the dark!

Damn, should really read that English Translation manual of my bike Ah well, guess I'll still stick 98 into my tank...why? Because I can

[The Stranger:Me]

so how do they run better?

would someone like to dyno their bike on a tank of 91, tank of 95 and tank of 98??

Just spoke to Toby (mechanic and I believe the shop foreman) at Henderson Motorcycles to see if I can get the GSXR on the dyno for this.

I asked him what he thought the outcome of a dyno run would be. He commented that he doubted there would be much difference at top end if any. He said he felt you may notice it in low to mid range.

This pretty well lines up with my experience on the Blackbird.

He also has a K3 GSXR 1000 and commented that he experiences pinging around town on 91 also and 98 eliminated this, but otherwise couldn't feel any difference in power on the GSXR.

Got to talk to Adam (at Henderson Motorcycles) to see if I can get it on the dyno though. I will try and go see him on Saturday and see if he will indulge me.

["D" FZ1]

91 is fine for most smaller bikes.

[Jeaves]

This thread is getting interesting...so will add a little now and some more afterwards.

Ponder this question for now.

How does your bike know what fuel you are putting in / running.

[The_Dover]

fuckin hell CaN, I'm not arguing about it for the gixxer you tit, suzuki state 95 RON or above for it.

it's a high compression, performance engine.

IS A GN250?? OR A GSF250? I'm talking about people who run 98 and say it makes a performance difference to their shit heap 250 or toyota corolla.