Higher octane means more ignition advance?

[RempageR1]

Hi,

From reading a lot of articles on the internet, it seems the higher octane fuel you run, the farther you can advance your ignition. Normally the lowest octane you can put in the Vmax is 86. Since I live in the Netherlands and we have only 95 and 98 octane (nothing lower), it seems to make sense to advance the ignition. According to my Haynes manual, the maximum advance is 43 degrees at 9000 rpm. Is there a theoretical way of predicting how far I can go with 95 octane without knocking?

Has anybody got any experience with this that they want to share? Will I actually gain some power with this? As I have the Ignitech unit, I can setup the ignition timing myself.

With your help, I`m planning on testing some maps to see what gives me the most power without running the risk of knocking.

Thank you!

 

[VMax-Mike]

Call Sean and buy a call Sean and buy a dino 3000 it will advance your timing for you and you get quite a few settings

 

[RempageR1]

Call Sean and buy a call Sean and buy a dino 3000 it will advance your timing for you and you get quite a few settings

Hi,

I do not want the Dyno3000 as my Ignitech unit can do so much more than the old Dyno3000 units can. In the manual of the D3, the curves are shown for each setting so I can try these as well on my unit. However, in that manual, no mention is made for octane so those curves might also be intended for low octane gas.

Since I want to run 95 octane, it is still unclear how far I theoretically can go and what it would yield in terms of power.

Thank you.

 

[MaxMidnight]

The 86 figure quoted in Haynes is for US fuel but it doesn't sate which measurement it is using; I would assume it is AKI(?)

If my assumption is correct it is equivalent to 90.5 RON so not as great a difference from our fuel as you may have thought.

I have used 95 & 98 Ron fuel and have also run the bike with a gizmo that advanced the ignition by 1.5 degrees.

I can't say that I noticed any difference so would conclude that whilst the point you make is correct, in the real world you wouldn't see any tangible benefit from altering the advance on a standard motor.

 

[Rusty McNeil]

Theoretically maximum power is made right on the ragged edge of detonation, whether it's from lower octane fuel, leaner A/F mixture, or advanced timing or any combination thereof.

When my motor was internally stock I played around with higher octane pump gas (93) and 100 octane race gas, along with playing around with the settings on my Dyna3000 and by seat of the pants and quarter mile times and trap speeds never really saw any benefit, and in some cases a true loss of ET or trap speed.

I ended up going back to 87 octane and Curve 3 for best results.

Too much octane can actually lose power as it burns slower, advancing the timing can offset that and get you back to where you started or perhaps even better probably but it's really all trial and error I think and has to be proved out on a dyno or at the track to find the best combination.

 

[satariel666]

The 86 figure quoted in Haynes is for US fuel but it doesn't sate which measurement it is using; I would assume it is AKI(?)

If my assumption is correct it is equivalent to 90.5 RON so not as great a difference from our fuel as you may have thought.

I have used 95 & 98 Ron fuel and have also run the bike with a gizmo that advanced the ignition by 1.5 degrees.

I can't say that I noticed any difference so would conclude that whilst the point you make is correct, in the real world you wouldn't see any tangible benefit from altering the advance on a standard motor.

Dont you guys have there on islands a SHELL V-POWER 100 octane fuel?
Made in Germany and make a difference of a lot

Hi,

From reading a lot of articles on the internet, it seems the higher octane fuel you run, the farther you can advance your ignition. Normally the lowest octane you can put in the Vmax is 86. Since I live in the Netherlands and we have only 95 and 98 octane (nothing lower), it seems to make sense to advance the ignition. According to my Haynes manual, the maximum advance is 43 degrees at 9000 rpm. Is there a theoretical way of predicting how far I can go with 95 octane without knocking?

Has anybody got any experience with this that they want to share? Will I actually gain some power with this? As I have the Ignitech unit, I can setup the ignition timing myself.

With your help, I`m planning on testing some maps to see what gives me the most power without running the risk of knocking.

Thank you!

Your engine running a stock compression would not do any better with higher ooctane fuel. We have here the fuel type I mentioned above which makes a diffrence actually but,
not with max power gains...Engine runs better, throttle response is much sharper and you may get some "tens" extra to your acceleration time but that Im afraid would be all. However if you do wish to have some advantages by playing with ignition curves you must upgrade your engine.

 

[RempageR1]

Thanks all. So in theory it would be possible to compensate for the higher octane which in this case is a bad thing, but I should not get my hopes up it will do that much.

Upgrading the engine is not on the agenda, too expensive at this time.

I will have a go with some curves on the Dyno and let you know how it went.