Effects of octane boost

Hi all-I use STP octane boost In my yz400f. I also used it in my 250f. My dad buys 87 octane, and he lets me use it in my bikes, so for me it's cheaper to just use the 87+octane boost. I always use 1/2 of the bottle in 5 gallons, so it becomes 91 octane. However, it just occurred to me that running octane boost may have adverse effects. Any opinions on this would be appreciated.

First, I very seriously doubt that you're getting anywhere near 91 AKI octane by adding the booster to 87 AKI gas.  Maybe 89, if you're lucky.

 

Second, octane boosters that actually do anything are nothing more than the same components used to blend gasoline in the first place, so no, reputable name boosters won't hurt anything, either. 

 

Just buy premium. 

Don't put 87 octane in a bike

What can you expect from running 91 with the octane booster?

You have to mix a good bit of octane booster to see results. Just buy 91 or 93 pump gas. If you go higher you may run into timing problems. To much trouble to mess with IMO

What can you expect from running 91 with the octane booster?

 

If you run the maximum recommended amount of most of them, you might get all the way to 92 (this is 92 as posted on US gas pumps as "AKI").  If you don't ping on 91, that will do you no good at all after all that expense.

1 gallon of 87 gas = $2.20

1 gallon of 92 gas = $2.40

5 gallons of 87 gas = $11.00 + boost?

5 gallons of 92 gas = $12.00

There is no logic in boosting the 87 octane. Spend an extra $1 for the 5 gallons and add the boost to that if you think you really need it?

Just run e85 and be done xD

Actually, has anyone run 1:3 e85 to 93 before? I do it in my car on track days, but it is direct injected.

Ethanol, in any form or percentage is a garbage grade fuel.  It's low energy, and it's hygroscopic on top of that.

Ethanol, in any form or percentage is a garbage grade fuel. It's low energy, and it's hygroscopic on top of that.

I I run straight e85 in my car I get 28 more whp and 24 more wtq over 93 octane pump gas due to increased timing.

Wonderful.  Now try gasoline with an AKI equivalent octane of 97 or so ( about 93-94 MON or 105-110 RON). 

Wonderful. Now try gasoline with an AKI equivalent octane of 97 or so ( about 93-94 MON or 105-110 RON).

pure gasoline is not readily available to everyone. I have dynoed my car on 110 sunco fuel as well. The e85 map puts out better numbers. As a side note, it has more oxygen in the fuel. And it is not 6 dollars a gallon.

Whatever you like.  No motorcycle of mine will ever have that much ethanol in it under any circumstances.  :thumbsdn:

 

Another problem with it is that all alcohols are "dry" fuels.  The compression rings get virtually all of their lubrication from the fuel they come in contact with.  Alcohols just aren't as "slick" as gasoline, and you should always run top oil with them.

Whatever you like. No motorcycle of mine will ever have that much ethanol in it under any circumstances. :thumbsdn:

Another problem with it is that all alcohols are "dry" fuels. The compression rings get virtually all of their lubrication from the fuel they come in contact with. Alcohols just aren't as "slick" as gasoline, and you should always run top oil with it.

I'm not saying I'm putting e85 in my bike. It would gum my carb up really quick from sitting two week. I am curious about mixing 1:3 to obtain a higher octane level. However it would do no good if the timing is bit advanced. If it was a fuel injected bike you could adjust the fuel maps or TRIM would take care of it, but for carbed bikes... run 93.

If one were to actually need an increase in octane from pump premium, which is rare, really, a less expensive and much more effective way to bump it up a notch is to use toluene at about 15% in your pump gas.  Toluene is a normal component of many pump gasolines, and most racing gasolines.  Instead of getting barely a one octane increase, you can move the number up s much as 3 with the stuff.  Most paint or hardware outlets have it.

 

If you add that much, you may very well need to jet up a step on the main jet.

If one were to actually need an increase in octane from pump premium, which is rare, really, a less expensive and much more effective way to bump it up a notch is to use toluene at about 15% in your pump gas. Toluene is a normal component of many pump gasolines, and most racing gasolines. Instead of getting barely a one octane increase, you can move the number up s much as 3 with the stuff. Most paint or hardware outlets have it.

If you add that much, you may very well need to jet up a step on the main jet.

Why would he need to jet it up with a bump in toluene?

It tends to make the engine run a little lean otherwise.  Depends on how you're jetted before you add it, and on what percentage you add in.  If the bike's a bit fat already, it may need no adjustments.  But I've seen people use up to 20% toluene by volume, too.

 

Adding toluene usually will also boost the thermal value of most pump gasolines.

Gray, quick question. My manual for my 03 yzf 450 calls for no less than 95 octane but I use ethanol free 87 and there's no pre det or ping of any kind. Does that mean I'm OK using this fuel?

First, the manual calls for 95 Research Octane (RON).  The gas pumps where you are are labeled with the octane rating expressed as "AKI" (anti-knock index), same as the US, and that's an average of the Research and Motor Octane rating methods.  91 AKI and 95 RON are about the same.

 

If it's cold enough, or if you're at a high enough altitude, you can get away with running 87, but frankly, the risk of damage is high enough that I wouldn't.

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