TorqueSteer Posted July 10, 2007 Report Share Posted July 10, 2007 So in theory, if you have no external variables such as temperature change, altitude change etc.. you would want to be at the lowest octane before seeing any pre-ignition? Link to comment Share on other sites More sharing options...
thelostartof Posted July 10, 2007 Report Share Posted July 10, 2007 So in theory, if you have no external variables such as temperature change, altitude change etc.. you would want to be at the lowest octane before seeing any pre-ignition?Yes Link to comment Share on other sites More sharing options...
Che'_Moderator Posted July 10, 2007 Report Share Posted July 10, 2007 Actually they are the new fuel injected ITB engines on the 1000cc bikes ... but ehSomething is screwy there Link to comment Share on other sites More sharing options...
thelostartof Posted July 10, 2007 Report Share Posted July 10, 2007 Something is screwy thereIF you say so, but then again the bud of mine that is on an AMA race team all of thier bikes make more power on 87 oct than on thier race gas, and being all they run are the new 1000c fuel injected bikes, mostly suzuki engines Link to comment Share on other sites More sharing options...
Che'_Moderator Posted July 10, 2007 Report Share Posted July 10, 2007 IF you say so, but then again the bud of mine that is on an AMA race team all of thier bikes make more power on 87 oct than on thier race gas, and being all they run are the new 1000c fuel injected bikes, mostly suzuki enginesIt is screwy. Have never seen 87 suggested for 13k+ RPM Link to comment Share on other sites More sharing options...
thelostartof Posted July 10, 2007 Report Share Posted July 10, 2007 It is screwy. Have never seen 87 suggested for 13k+ RPMNor myself, but he said even the racers and tuners were in aw that on 87oct is where they would get the best peak numbers Link to comment Share on other sites More sharing options...
thelostartof Posted July 10, 2007 Report Share Posted July 10, 2007 Gotta stay away from leaded gas, mang. Around here 100 is unleaded and in some spots you can find 110 unleaded, but for the most part, anything over 100 is leaded. Which is bad for O2 sensors as you found out. eh i have about 45k+ on an NTK sensor that spent the first 10k of its life seeing a 50/50 mix of 100oct unleaded and 115 leaded .... then again the NTK sensors are actually built for leaded use and last much longer with it. oh and this said sensor just passed smog with flying colors running 40% larger injectors on a fairly good size cammed car. still gets ~20mpg on the highway .... not bad being i used to only get 16mpg when the car was stock haha Link to comment Share on other sites More sharing options...
GT2 Posted July 10, 2007 Report Share Posted July 10, 2007 IF you say so, but then again the bud of mine that is on an AMA race team all of thier bikes make more power on 87 oct than on thier race gas, and being all they run are the new 1000c fuel injected bikes, mostly suzuki enginesA couple of guesses here.The load on a 13000 rpm bike engine is nothing like the load on an auto.Sure it will make better numbers, but it may not last as long! :) Link to comment Share on other sites More sharing options...
Che'_Moderator Posted July 10, 2007 Report Share Posted July 10, 2007 A couple of guesses here.The load on a 13000 rpm bike engine is nothing like the load on an auto.Sure it will make better numbers, but it may not last as long! No knock sensor is the new pegs Link to comment Share on other sites More sharing options...
Zulu Posted July 11, 2007 Report Share Posted July 11, 2007 Octane number represents number of anti-knock additives in gas...if certain engine is configured with fuel trim & ignition advance to produce pressures requiring higher octane, then it's necessary regardless of conditions. But if the pressure in the cylinders doesn't require the additional octane than no...doesn't matter if you're turning 13K RPMs if the pressure in the cylinders doesn't need the extra anti-knock additive. Then you can get away with lower octane.If engine isn't tuned for race fuel, containing a lot more additives then 93 obviously...slows burn down in combustion chamber so much that you lose power. Race gas needs a leaner mixture & more aggressive ignition timing. Link to comment Share on other sites More sharing options...
GT2 Posted July 11, 2007 Report Share Posted July 11, 2007 Octane number represents number of anti-knock additives in gas...if certain engine is configured with fuel trim & ignition advance to produce pressures requiring higher octane, then it's necessary regardless of conditions. But if the pressure in the cylinders doesn't require the additional octane than no...doesn't matter if you're turning 13K RPMs if the pressure in the cylinders doesn't need the extra anti-knock additive. Then you can get away with lower octane.If engine isn't tuned for race fuel, containing a lot more additives then 93 obviously...slows burn down in combustion chamber so much that you lose power. Race gas needs a leaner mixture & more aggressive ignition timing.I assumed we were talking about a real race bike engine, but after re-reading I think they are talking about stock engines! Link to comment Share on other sites More sharing options...
Guest Guest_grnmachine02_* Posted July 12, 2007 Report Share Posted July 12, 2007 DONT do this.. i burned out both O2 sensors in like 3 days with this idea must use gas that is advertised "oxygen sensor safe" Link to comment Share on other sites More sharing options...
zazzn Posted July 12, 2007 Report Share Posted July 12, 2007 I love how you guys say no real use when you have no real world experiance. If you have your boost up i'm almost 100% sure you will see gains by adding high octane c16 or similar fuel.Easy way to tell is to add some and let it mix around at the track next time or even on the dyno. The extra octane will let you run higher timing for sure. 18 PSI even on the supra's 3L twins retards timing on 91. Again people who say the engine is not knocking how about do your self a favor, look at the timing under boost on 91 and then go out on a 50/50 mix of race/pump and look at the timing again underboost with the OBDII reader. You'll instantly FEEL and see the diff. It is true though it kills 02 sensors VERY fast and Cats. Link to comment Share on other sites More sharing options...
Che'_Moderator Posted July 12, 2007 Report Share Posted July 12, 2007 I love how you guys say no real use when you have no real world experiance. If you have your boost up i'm almost 100% sure you will see gains by adding high octane c16 or similar fuel.Easy way to tell is to add some and let it mix around at the track next time or even on the dyno. The extra octane will let you run higher timing for sure. 18 PSI even on the supra's 3L twins retards timing on 91. Again people who say the engine is not knocking how about do your self a favor, look at the timing under boost on 91 and then go out on a 50/50 mix of race/pump and look at the timing again underboost with the OBDII reader. You'll instantly FEEL and see the diff. It is true though it kills 02 sensors VERY fast and Cats.You're right. I have no experience at all. Its really good to know your supra which suffers timing pull is a model for every engine ever built. 2 gold stars for you Link to comment Share on other sites More sharing options...
zazzn Posted July 12, 2007 Report Share Posted July 12, 2007 You're right. I have no experience at all. Its really good to know your supra which suffers timing pull is a model for every engine ever built. 2 gold stars for youYes because that statment was directed completely at you. Nice attempt to jab. You have only made 1 statement of use in this tread."Excess octane results in less mileage and HP but whatever"#1 Can you please produce any proof of your statment that you get less HP and less milage from octane? (never heard about this before and honestly intrested)#2 How can you prove that it's excess octane, when you dont know what setup someone is running? (not everyone is stock)The only place I can see higher octane then 91 give less milage is sunoco 94 here in Canada because it contains 10% alcohol. Whist it does give higher octane it also delivers worse milage due to alcohol buring up to 30% more to produce the same energy. I don't see how going from 87 to 91 will create worse milage since with better fuel you'll get a cleaner burn with higher timing which equates into less fuel needed to make the same power since the T5's a specificlly designed for higher octane fuel. They are not 8.1 compression and do not run low boost. 10 PSI pretty high for a stock car. 3#Have you EVER hooked up and datalogged the OBDII timing logs with 91 vs 94 or 91 vs 116? Do you have results? Time slips one with and with out? what was your setup?Bascially all i'm saying is the lazy 1 line answer you gave is a load of horse dung without knowing the whole story.Anyone planning on using race gas USUALLY has the boost on on their car which means they PROBABLY will gain something power wise. Link to comment Share on other sites More sharing options...
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