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You dont need higher octane unless you have valve knocking, your wasting money on 93 if you dont have any engine mods done...
 

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i would not waste money on anything above 93 if u dont have engine mods. 93 is the best bet, i've tried lower grades and the throttle response was not there.
 

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papis_18 said:
i would not waste money on anything above 93 if u dont have engine mods. 93 is the best bet, i've tried lower grades and the throttle response was not there.
Sorry to say but octane will not change throttle response unless your engine needs the higher octane...
 

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The only mods that would require anything more than regular unleaded pump gas is a higher compression piston or advanced ignition timing.

87 octane is all a stock raptor needs, and any more is wasted money.

Even a mildly modifed motor, like with a cam and a pipe, will still only require 87 octane.
 

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a piston raises your compression..which requires higher octane
depending on your cam, port job, valve set-up, flow rate....also have an impact on on your octane rating....they can actually lower your needed octane rating slightly. a 12:1 compression motor could possibly run on pump gas if built right....(raptor 660 motor)...although I wouldn't give it a try with my motor! :lol:
 

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everytime i use 87 octane it just doesn't have the throttle response as it does when i use 93. what could cause this if its not the fuel grade?
 

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rt said:
a piston raises your compression..which requires higher octane
depending on your cam, port job, valve set-up, flow rate....also have an impact on on your octane rating....they can actually lower your needed octane rating slightly. a 12:1 compression motor could possibly run on pump gas if built right....(raptor 660 motor)...although I wouldn't give it a try with my motor! :lol:
My 12:1 I usually run 104 octane. Last week when I had the truck at the track I grabbed 5 gallons of c16 race fuel and now running 1 gallon of it and filling the rest with 93. I didnt even wanna mess with trying to run pump gas
 

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It's true that a stock engine only needs 87 and giving it anymore wont really increase power. It is also true that the build of an engine determines what octane needs to be ran. Cams, porting...etc will lessen the octane rating that you need to run to prevent detonation and pre-ignition.

My 446 Wolverine will actually make more power on Sunoco Ultra 94 than with 110 octane race fuel. Something to think about too. Now I am not saying that the lowest possible octane rating that engine "X" needs to run safely will be the one that it produces the most power with but alot of times a lower rating will make better power. The reason is that the lower the rating, the more energy it has when it combusts due to less additives and retardants.

As for less throttle response with 87, could have been slightly watered down or lost some of its energy from sitting too long at the station or in your tank. Could have been alot of things.

The stock engine only has a 9.2:1 compression ratio so high octane isn't really needed.
 

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I tricked a friend into thinking I was putting 94 octane into his quad, when actually I was putting 87 in it..
He had just ran a tank of 87 fuel and said it ran $hitty. He got on his quad and he said it felt more responsive and said it felt like it even had more power...Till I broke the ice,..and I told hime that it wasn't 94 octane but 87 instead......
I think it purely psycological when most say that the bike runs better on higher octane when the motors designed for 87-89. But if you must pay higher at the pump to let yourself pretend that your getting more hp and your bike is running better,..go for it!
I tried 94 on my bike before and it actually felt like it was loosing power.

This is my opinion, not fact: I would think that if you out 110 octane in a stock motor, it would run like $hit. The higher comp piston actually helps detonate the fuel.. similar to deisel (the motor uses piston compression to ignite the mix rather than a spark plug). higher octane needs more energy to ignite, or can take more energy than lower octane before it ignites. the higher comp pistons act as a catalyst to help the higher octane fuel ignite with a stock plug.
if that compression isn't there to help out with the ignition phase, I would think that there would be a lot of un-burnt fuel running around,..(especially a gap of 87 to 110 octane),. making the motor appear that its running rich, and possibly back firing.

Like I said my opinion!
 

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rt said:
I tricked a friend into thinking I was putting 94 octane into his quad, when actually I was putting 87 in it..
He had just ran a tank of 87 fuel and said it ran $hitty. He got on his quad and he said it felt more responsive and said it felt like it even had more power...Till I broke the ice,..and I told hime that it wasn't 94 octane but 87 instead......
I think it purely psycological when most say that the bike runs better on higher octane when the motors designed for 87-89. But if you must pay higher at the pump to let yourself pretend that your getting more hp and your bike is running better,..go for it!
I tried 94 on my bike before and it actually felt like it was loosing power.

This is my opinion, not fact: I would think that if you out 110 octane in a stock motor, it would run like $hit. The higher comp piston actually helps detonate the fuel.. similar to deisel (the motor uses piston compression to ignite the mix rather than a spark plug). higher octane needs more energy to ignite, or can take more energy than lower octane before it ignites. the higher comp pistons act as a catalyst to help the higher octane fuel ignite with a stock plug.
if that compression isn't there to help out with the ignition phase, I would think that there would be a lot of un-burnt fuel running around,..(especially a gap of 87 to 110 octane),. making the motor appear that its running rich, and possibly back firing.

Like I said my opinion!
lolz sounds like placebo. but when i use 87 i cannot feel the power until higher rpms but when i use 93 i can feel the power right when i push the throttle. i am going to run 87 next time i fill up just to make sure im not experiencing placebo lolz.
 

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My 05 owners manual says " engine is designed to use pump octane number of 86 or higher or a research octane number of 91 or higher "
Also watch out for methanol. your low power on 87 may be caused by gasohol.
 

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als660r said:
My 05 owners manual says " engine is designed to use pump octane number of 86 or higher or a research octane number of 91 or higher "
Also watch out for methanol. your low power on 87 may be caused by gasohol.
Pump octane is what's advertised on US pumps, (R+M)/2. R in that equation is research octane, and it's included because in some countries outside the US research octane is how the fuel is labeled.

I often ran 87 octane through a stock bore 11:1 compression stage 1 cammed unported 660 raptor on 90 degree days without any knock or pre-detonation. It wasn't my choice as I usually used 93 octane because of the compression, but it was all we had and it worked fine.

There is a difference between high octane fuel and oxygenated fuel. Oxygenated fuel will make more power, but not because of a different octane rating.
 

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rt - No. You are wrong on this theory, but I like your thinking. What you have just stated is what you have to prevent. When charge heat is aiding ignition it is time to run a higher octane. This is known as detonation. This is when the charge is igniting via heat of compression and plug spark almost simultaneously. This will lead to cylinder damage.

Diesels and Top Fuel cars (after half track) run off of pre-ignition. They were designed so that it pre-ignites around 20 or so degrees before TDC. If pre-ignition happens on a gasoline engine, you will have opposing forces in the cylinder. This will lead to holes in the piston. What ends up happening is that the mixture ignites while the piston is still on its way up to TDC (this isn't when diesels fire). So you have the piston speeding up to TDC and then all the sudden and explosion hitting it forcing it back down before it gets there.

Your solution for running 110 octane and the stock plug not burning it all would be to run a hotter plug. Thats exactly what they are for.
 

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I run 87 or 91. I noticed a little difference in bottome end power and in top end too. With 91 octane I could feel the bike wanting to pull harder and keeping pulling. With 87 it was sluggish and felt like I was maxxed out even though i now it could pull a little more.
 

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Desert Racer said:
I run 87 or 91. I noticed a little difference in bottome end power and in top end too. With 91 octane I could feel the bike wanting to pull harder and keeping pulling. With 87 it was sluggish and felt like I was maxxed out even though i now it could pull a little more.
this is what i was saying also, there has to be a reason for the power loss.
 
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