It helps it. I will try to get a clarification on octane ratings and their effects. I always forget it if burns cooler or if its the flame burning slower or faster. I can't remember and don't want to post something that is not correct. The motor was designed to run on 87 octane. Putting in higher octane with stock compression will make the sled slightly slower on top end. It won't hurt the motor, but you won't be developing max HP. An easy, but expensive test. Drain the fuel in your sled and put in 5 gallons of 114 octane fuel. Let me know how it runs. You are going to tell me if sounds really rich and fat on top end. If you have a question of fuel quality, then go ahead and run 89 octane. I have been running 87 octane all year on lakes wide open with no problems. If I had any gas left over from race season, I would do this for you and record the EGT temps with both fuels. Higher octane also helps control detonation, which this motor won't do on top end because its overly safe. If you were running an advanced keyway, then I might think about it. Its spot on through the mid range and might need extra octane with a 3 deg key.
Looney, the answer to your question is higher octane burns COOLER. This is backwards from what most people think. The myth is "Higher octane must be better gas, which means I'll get more power." In all actuallity, this is the opposite. High octane gas only helps the motor from "pinging." As mentioned, if you up the compression, you need to increase octane rating. It won't hurt your motor (it helps to run higher octane in COLD weather where scoring from detonation might occur) but doesn't create power. The lower octane number you can run with out hurting your motor will make the most power. Same goes for your vehicle. On cold days, it is easier on your engine to run with low oct. Low octane burns hotter because the "flash point" is lower. This causes it to also burn faster than high oct. numbers. Hope this helps.
ok...if i use gas with Ethanol in it and the switch on Regular,wouldn't that lean it out on top end??? Or would it be to lean midrange,would 104 octain boost lean it out on top with the switch on regular..thanks
I can only answer this one more time. Octane will make the motor richer, not leaner. It is already safe on top end. If you add octane booster, it will be SLOWER. The reason racers use high octane fuel is they are running much higher compression ratios and more advanced timing than stockers do. The motor will be safer(less chance of detonation), but will NOT devolop max HP with high octane fuel. If you run ethanol fuel, and the switch in regular, you are taking the chance of running lean in the middle. Ethanol fuels carry more oxygen, which would require more fuel throughout the entire range. Thats what the switch does, it adds 3% more fuel everywhere. Your sled will run crisper and be slightly faster on top end with 87 octane. Any octane above that and you will wasting money and not letting the sled perform as it should. gls has repeatedly answered this question on Amsnow. The only time you might want the extra octane is if they may be a question of fuel quality(bad gas). You can't lean out the fuel on top by changing octane numbers, unless you can inject lower octane gas only on top end. If you figure that one out, let me know and I'll try it. Hope this helps.
Guys, you only need to run 87 octane. However if you feel better run a higher octane....not 114 as mentioned in here somewhere but up to what you can get at the pumps is fine. I run 87 when dragging, and 92 for trails. The higher octane is just to prevent detonation. It's just added comfort that's all, and I'd rather pay for it.
I plan on hittin' that ethynol switch this weekend at a local radar run event, I've got the go-go juice coming to me within 2 days and i was wondering if anyone else had some numbers to throw at me. Fastest I've gotten my F7 was 109 (144 picks, all else stock) I also have my MBRP can coming this week too. Anyway how much faster can I expect to run?? AMSnow's report on "Hot fuel" was done on a Ski-Doo with many jetting changes, they said nothing about a Firecat running it. The Doo's power was about the same mid-range.
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