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Back in Black
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Depends. Does your bike have a catalytic converter? If no, than absolutely will not hurt anything. If it does have one, you must run unleaded race fuel.

Why run it tho? There's no real benefit unless you've got a turbo, high compression, nitrous, etc.
 

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Your manuel says the octane that should be run in your bike. This topic is discussed like 3-4 times a month, and the conclusion is always that running anything but what your manuel recommends can be harmful for your bike.

I don't really want to go into all the reasonswhy its bad, because im sure someone that knows more then me will go into it. But a couple reasons are that higher octane is harder to burn for ur engine, and if your engine is not meant to burn high octane, it will gum up your pistons and cause carbonation problems. Higher octane can also decrease horsepower (SLIGHTLY) because the higher octane is harder to burn.
 

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Superbike fan
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Every time I go to a race track and a race bike or car goes by burning that fuel it makes me happy. That stuff smells so good. I've been tempted to get some just for the smell it leaves. At Road America there were two pumps: 110 octane leaded and 100 octane unleaded

My Kawasaki has a catalytic converter and leaded gas would ruin it. So, yours may have one unless they went backwards or you have an aftermarket full exhaust.

It would make sense to advance timing with higher octane. More timing can be a benefit to power especially low end.

I still haven't found anything good to read about the fuel injection on bikes today. I know some car EFI systems control timing and can take advantage of higher octane by advancing timing.
 

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~ Master Technician ~
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Race gas is a waste of money if you engine is not set up for it.
 

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Yeah, VP is about $12.00 a Gallon. Not something I will pay for and I RACE let alone for street use...
 

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yes its ok, but youll actually be losing HP as it takes longer to burn than normal gas.
 

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Kawpuke Extraordinare!
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Unless your bike is pinging on the highest octane pump gas you can get there is no need to run anything else. Oxygenated fuels are a different story...
 

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voted for an American
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You only need race fuel if you have some power-adder or very high compression. C-12, 14 and 16 are leaded and they will leave lead deposits in your combustion chamber, valves and sparkplugs. Look at the cars exhaust tip when they run racefuel, what do you think that gray-blueish coating is? When I had my turbo car I used C-16 (117 octane leaded) so I could run about 15 more psi boost pressure, more timing and a bit leaner AFR's. The horsepower difference was outrageous but that's because I was able to change those parameters on my car. Your bike will not go faster on race fuel.
 

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2001FZ1 said:
Race gas is a waste of money if you engine is not set up for it.
+1

but it does smell cool. i can't understand why so many guys run this at the track. even with a full race exhaust system you still don't need it unless you are running higher compression.
 

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redcbrla said:
+1

but it does smell cool. i can't understand why so many guys run this at the track. even with a full race exhaust system you still don't need it unless you are running higher compression.
I remember shaving off .3 and gained 4 mph by just running race gas, 100% stock exept no exhaust. Cars with knock sensors, especially if they're older can benefit by just adding race gas.
 

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TTsixxer said:
I remember shaving off .3 and gained 4 mph by just running race gas, 100% stock exept no exhaust. Cars with knock sensors, especially if they're older can benefit by just adding race gas.

I would have to see it to believe it.
 

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I know some car EFI systems control timing and can take advantage of higher octane by advancing timing.
Bikes can't. No knock sensors in our bikes and the EFI in modern sportbikes has zero learning adaption. No air metering either, hence the need to retune with VE mods. A simple system, similar to Motronic from the 1980s.
 

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2001FZ1 said:
I would have to see it to believe it.
Older cars tend to have some carbon buildup on the pistons and combustion chambers, can cause detonation and then the engine pings, the knock sensor picks up the ping and it retards the ignition timing and in my car's case it will also lower the boost pressure. When you put race fuel, the less volatile fuel will be more detonation resistant, the engine doesn't ping so that means the knock sensor will not tell the ECU to pull back the timing and reduce the boost pressure. The result is a good 30 hp increase or so. My guess is that you have no idea how much power can be lost when your ignition timing is pulled back. I've seen it on the dyno myself, cars gaining hundreds of horsepower by just fixing a timing map.
 

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Older cars tend to have some carbon buildup on the pistons and combustion chambers, can cause detonation and then the engine pings, the knock sensor picks up the ping and it retards the ignition timing and in my car's case it will also lower the boost pressure. When you put race fuel, the less volatile fuel will be more detonation resistant, the engine doesn't ping so that means the knock sensor will not tell the ECU to pull back the timing and reduce the boost pressure. The result is a good 30 hp increase or so. My guess is that you have no idea how much power can be lost when your ignition timing is pulled back. I've seen it on the dyno myself, cars gaining hundreds of horsepower by just fixing a timing map.
I think FZ1 was talking about bikes. Haven't we established that bikes (unlike cars) cannot retard timing to avoid detonation?

And if you gain 'hundreds' of horsepower by 'fixing' a timing map, it's safe to say that the map was completely wrong to begin with.
 

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MAGNUM636 said:
I think FZ1 was talking about bikes. Haven't we established that bikes (unlike cars) cannot retard timing to avoid detonation?

And if you gain 'hundreds' of horsepower by 'fixing' a timing map, it's safe to say that the map was completely wrong to begin with.
He quoted me and said he has to see it to believe it, I was clearly talking about cars. Anyways, yes that dyno run was on a dodge stealth, he had 300 or so hp but the timing map was all messed up 8 degrees at 7000 rpm's lol. After the timing map fix, the car was making 500+.
 
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