Just curious as if anybody runs super unleaded or 94 Ultra in their quads......If so do you notice any difference between that and 89?

John

 

higher octane dosnt mean its more high performance or more explosive, the higher octane count keeps the fuel from Pre-Combusting under high compression. not even the sportsman 800 needs more than regular. your just throwing away your money :/

 

Spyder......
I wasn't saying that I run it.......I was just asking if anyone did........
John

 

I use 89. Never used anything else to do any comparision.

spyder6,
Whats the advantage of "keeps the fuel from Pre-Combusting under high compression"

 

in a high compression motor, the oxygen, gas and everything is compressed to higher limits than normally. the higher limits allow for some forms of gasoline with low Octane levels to spontainiously combust, or dieseling. the compression is so high for the octane rateing that the gas just compresses, and ignites on its own, without any help from the sparkplug. the higher octane level you have it wont do that, and will allow for a clean, efficient, correctly timed, and powerfull compression, explosion and you get your power back.


if your running too low of an octane, you can hear your motor knocking, and its probebly not running very well

 

Put 110 Race Fuel in my stock 400 2003 Trailblazer at Glamis, ran out of plain fuel. It had trouble pulling itself, got to the beach store and put regular unleaded back in to bring back the life. My buddy wanted to know how much better it ran. It ran so bad you could not climb any big dunes on the way over for more fuel.

The Trailblazer 400 2-strock is 6.9 to 1 effective compression ratio.
Running 87 octane is all I need. Put 91-92 octane and the temp gage reads too hot.

Then added all the options below, HPD pipe, bigger carb, V-Force reeds, K&N etc.
Put in exhaust temp gage and it still runs fine on 87 octane. Put in premium and keep the front end on the ground, wheelies a lot easier with cheap fuel.

At 12 to 1 compression 98 - 100 octane should work fine
14 to 15 to 1 compression 102 -110 octane, depends on engine and plug you are running.

Keep it hot, a internal combustion engine produces horse power with heat, more heat more power, run engine cooler loose power, that is why a exhaust temp gage is so useful.

good luck..............................handycap

 

Spyder is right on this. There is no advantage to using the higher octane (well I guess your machine might pull you a little faster due to your wallet being lighter!!!) unless you are experiencing detonation/sparkknock. Gasoline should burn rapidly but not explosively inside the combustion chamber. When it burns too rapidly(or explodes) this is what causes detonation/ sparkknock and can damage the engine. The higher octane fuels prevent this by burning slower. (allows the spark plug to ignite the fuel vs. the heat from compression thus the term dieseling).Some dyno tests have shown that engines that don't need the higher octane fuels actually produce slightly less power when using it vs. lower octane fuels. Some people use it for thier own peace of mind I guess, but I don't have the extra money to waste on something I really don't have to have.

 

i agree you need engine heat to make the power but to a point to much heat will lose power try overheating it and see how much power you have. the higher octane will keep temp down if you need that also. if you want some great power in a 2 stroke try vp super oxygenated fuel!!!!!!!!!!!!!! have 400 race mod and it made enough of of differance i was paying the $9 a gallon for races or one really great weekend just my two cents worth

 

I have .020 off the head on a 250. I found I need to use 93 octane or it pings.

 

as far as i under stand in racing 2 strokes sleds they do not want alot of hot engines, hence the pumping of cold antifreeze though the engine to cool them down after runs. i know when i raced my mustang w/ outside cold air though the ram induction it seem to be faster w/ the colder engine. just my 2 cents.