Pump gas and race fuel expained

I've never run anything higher than 93 in my CBR...but I know the fancy stuff smells amazing

https://www.bikeminds.com/thethrottlestop/race-fuel-vs-pump-gas-for-motorcycles

 

A good and concise article. Thank you!

 

good read.

Question Can running expensive gas the a bike isnt tuned for be Bad? Or have a loss of Power? Had to run sunco 110 at the track in my stock CBR and it was choking bad at 12k to 14k. Never had a issue since going back to 93 (wont forget gas again)

 

Absolutely. 110 is MUCH harder to burn than 93. Your bike certainly wasn't detonating or pre-igniting, but I'll bet it had a whole whack of misfires. Did you pull the plugs after? Bet they were black as the inside of a cow ...

You won't damage the engine, but you certainly won't make anything remotely resembling the amount of power you would otherwise expect.

Like the article said, 93 in an engine set up for 87 is a waste of money and a loss of power. The higher octane allows greatly increased compression (increased power), altered ignition timing (more desireable ignition point), and altered 'jetting' that doesn't include added fuel to reduce detonation.

 

Just said a waste of money didnt say anything about not detonating which was why i asked. I didnt pull the plugs or rly worry about it much i was pretty sure it was the gas at the time. Never would have ran it but didnt have a choice. Next time ill buy gas off someone. If i run about again lol.

Should i be concerned about the plugs after that? Can a engine thats setup for 93 be retuned to run on lets just say that 110 as is or would you need to alter the timing or compression? To have it reliable

Thank you for the help!

 

If it ran properly once you had the right fuel, the plugs are fine.

Modifying an engine from 91 to 93 involves minor changes to timing and 'jetting', perhaps a skim of the head. Modifying an engine from 93 to 110 (and vice versa) requires significant changes to hard parts - piston profile, deck height, squish band, ports and valves, adding a supercharger, etc etc - as well as ignition timing.

 

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Very interesting I initially thought you could run any (higher) octane on any engine as long as it was tuned for it. Didn't understand hard parts needed to be changed. So anyone running race fuel has a engine built for it? Ive heard of people say they run mr12 or whatever and have a map switch for 93 too. How does that do both with out an engine swap or do they not rev the engine high on 93 because of fear of early detonation on a engine that was built around running mr12?

 

MR12 has an octane racting of 87; its magic comes by bringing along extra oxygen, so the map switch is probably both jetting and timing.

You -can- run a higher octane within limits, but if your engine works the best on 91, it will be slightly down on power on 93, and at risk of detonation under certain circumstances on 87 or 89. We're talking ragged-edge tuning here; the jetting / fuel maps on street bikes are FAR more conservative, allowing for safe operation on a wide variety of fuels. Retuning for 87 (because that's all you can get) from a ragged-edge 91 tune would involve richer mapping, as you would be using the fuel itself as an internal coolant to prevent deto. Going the other way, bumping from 91 to 93 would involve a leaner tune, as you'd use the hotter flame of a lean mix to increase the burn rate to compensate for the higher octane fuel's resistance to combustion. In either case, you would be down slightly on power, but not as badly as running 93 or 87 on a 91 map.

If you can adjust the ignition timing, you'll be able to re-tune for 93, and quite possibly be able to use increased ignition timing for more power than you had with 91, while avoiding knock / detonation thanks to the increased octane.

 

One of the biggest marketing schemes ever was when they labeled 93 octane fuel "Premium". It leads people to thinking "only the best for my shit!" and running higher octane fuel when it is unnecessary.

Running a higher octane fuel in your bike (or vehicle) that it isn't built/tuned for will not help anything. The only increase in acceleration you will get is from your wallet being lighter.

 

How about the additives/detergents that are supposedly in the higher octane fuels for cleaner fuel parts(injectors,lines,etc.)? Is that all bunk too? Also, I thought some of the higher octane fuels contains less ethanol than the lower octane stuff?

Always wanted to hear from someone in the know.

 

From what I've read a while back, the days of "premium" having more detergents than the 87 are long over.

I've been running MS98L as my "pump gas" in the R6 for a few reasons: 1: No ethanol, 2: It's the lowest octane stuff with consistent quality that's readily available from our trackside VP guy, since my bike is only mapped for MR12 right now. I worry about a tank of crappy pump 93 causing damage. It could very well be a baseless worry, but it's cheaper than a new engine.

 

Yep, most companies put additives/detergents in all of their fuels. And all of them (that I have seen) have the same ethanol content, unless it specifically states ethanol-free.

Luckily I have an E0 (ethanol-free) gas station about 300 yards from the house. That is all I run in everything.

 

Of course im talking about cars and street bikes and ATVs and shit. In the race bikes I run race fuel.

The 1299S is only mapped for U4.4.
The R6 has maps for U4.4 and MR12, with a map switch on the bars.
The Grom is mapped for pump and MR12, also with a switch on the bars.
The Outlaw is only mapped for pump gas, but I am trying to see if Rapidbike makes a tuner for it.

 

Effanol free 87 from for the bike

Same as my yard equipment

 

Mr12 in a grom.... Lol, go big or go home!

 

What's an Outlaw?

 

The pit bike (ATV)

I don't have a closeup picture, but that is it beside the canopy. I love that little thing. haha.

 

Here is a picture I found on google.

What's funny is that it has the same suspension and parts as the bigger one (it isn't a bargain basement kid toy like some of them). It is fuel injected and even has reverse. Haha. It was funny because they adjusted the suspension and set the sag for me when I picked it up.

One of the reasons I get so excited about racing weekends is because I get to play with the Outlaw. Haha

 

That's pretty cool...

Do you let the 12'o clock Boyz wheelie in front or after you?

 

Behind me. Of course.