Octane, Compression Ratio, and Detonation.
#21
09-25-2006 | 08:21 AM
Joined: Jun 2006
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RE: Octane, Compression Ratio, and Detonation.
ORIGINAL: Ocelaris
the K-series motors, k20a2 k20a3 k20a etc... are the newest Honda 4 cylinder auto motor series... the JDM motor is the K20a with slightly higher compression (not sure exactly off the top of my head the exact #s), cam profiles etc... some other things... they're ~20bhp more powerful, but also I assume advanced for higher octane gas.
that answers my question, advancing the timing for higher octane won't do much.
the K-series motors, k20a2 k20a3 k20a etc... are the newest Honda 4 cylinder auto motor series... the JDM motor is the K20a with slightly higher compression (not sure exactly off the top of my head the exact #s), cam profiles etc... some other things... they're ~20bhp more powerful, but also I assume advanced for higher octane gas.
that answers my question, advancing the timing for higher octane won't do much.
#22
09-25-2006 | 10:12 AM
Admin Emeritus & MVN
Joined: Jan 2000
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From: Conyers, GA
RE: Octane, Compression Ratio, and Detonation.
Generally when you raise compression significantly you tend to take out timing -- not add it in. Otherwise you get detonation. As for race cars ... NASCAR runs 12:1 in a 358 ci V8 -- adding in timing would grenade that bad boy.
I don't know for a fact that Honda isn't running different maps for different countries. The extra compression in a car motor would account for the 20hp -- timing may or may not be another factor.
In the states we use the R+M/2 formula for calculating octane at the pump. How about some of you guys across the pond find out and post how it's measured in your yard. Different formulas for calculating the octane would be a simple enough explanation on why they require higher octane in Oz.
I don't know for a fact that Honda isn't running different maps for different countries. The extra compression in a car motor would account for the 20hp -- timing may or may not be another factor.
In the states we use the R+M/2 formula for calculating octane at the pump. How about some of you guys across the pond find out and post how it's measured in your yard. Different formulas for calculating the octane would be a simple enough explanation on why they require higher octane in Oz.
#23
09-28-2006 | 06:14 AM
Joined: Sep 2006
Posts: 118
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RE: Octane, Compression Ratio, and Detonation.
Some of these posts when over my head but from Slipper's original, I learned I have to increase my Omega 3 fatty acids. Kidding aside, I went to "regular" (washington state gas) from my 3rd tank on and havnt found a reason to go back, not even to the "mid" grade. ps Im a street rider only.
#24
10-10-2006 | 03:21 AM
Joined: Oct 2006
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RE: Octane, Compression Ratio, and Detonation.
Good thread guys. Just a heads up though. I have a 2004 CBR 600RR and in the manual it states 86 octane or higher is the recommended for this bike. With that said if you look in the owner's manual, we should be changing gears every 7miles our so until we get into 6th gear, so basically about 30miles an hour or so in 6th gear is recommended. With that kind of riding, yeah I guess 86 or higher octane is perfect for that application. But who the hell rides like that? If your riding hard like the average joe, than a higher octane gas is recommended in my opinion. Another heads up for you guys and gals. The other day I looked under my back seat, and noticed a sticker with info for my bike. You know info like spark gap size, tire info, and oh yeah octane recommendation. CHECK THIS OUT.... Honda recommends 91 octane for my bike afterall. No sh*t. Check your sticker and let me know if yours has the same thing. I bought my bike in Canada, but that shouldn't make a difference. Ever since I noticed the sticker, I've switched to 91 octane. Bike runs the same as it was with 87 octane to tell you the truth. But I just wanted to go with what the sticker seat said. I just picked the higher number, to make sure because in 2nd gear I'm doing over a hundred, so I just don't feel right using 87. Why would there be a discreptancy from what is stated in the manual and what is stated under the back seat on a sticker? Okay guys you know the drill, go to your back seat and read the sticker, do you see 91 on there? Let me know, and let the forum know this as well. I'd hate to see someone screw up there bike, because they were running 87 when really we should be riding 91 minimum. Just my 2 canadian cents. And no I'm not trying to argue or go against other opinions on here, just reading you the facts, thats all.
#25
10-10-2006 | 03:52 AM
Joined: Jun 2005
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RE: Octane, Compression Ratio, and Detonation.
ORIGINAL: HondaCBR600RRhunk
Good thread guys. Just a heads up though. I have a 2004 CBR 600RR and in the manual it states 86 octane or higher is the recommended for this bike. With that said if you look in the owner's manual, we should be changing gears every 7miles our so until we get into 6th gear, so basically about 30miles an hour or so in 6th gear is recommended. With that kind of riding, yeah I guess 86 or higher octane is perfect for that application. But who the hell rides like that? If your riding hard like the average joe, than a higher octane gas is recommended in my opinion. Another heads up for you guys and gals. The other day I looked under my back seat, and noticed a sticker with info for my bike. You know info like spark gap size, tire info, and oh yeah octane recommendation. CHECK THIS OUT.... Honda recommends 91 octane for my bike afterall. No sh*t. Check your sticker and let me know if yours has the same thing. I bought my bike in Canada, but that shouldn't make a difference. Ever since I noticed the sticker, I've switched to 91 octane. Bike runs the same as it was with 87 octane to tell you the truth. But I just wanted to go with what the sticker seat said. I just picked the higher number, to make sure because in 2nd gear I'm doing over a hundred, so I just don't feel right using 87. Why would there be a discreptancy from what is stated in the manual and what is stated under the back seat on a sticker? Okay guys you know the drill, go to your back seat and read the sticker, do you see 91 on there? Let me know, and let the forum know this as well. I'd hate to see someone screw up there bike, because they were running 87 when really we should be riding 91 minimum. Just my 2 canadian cents. And no I'm not trying to argue or go against other opinions on here, just reading you the facts, thats all.
Good thread guys. Just a heads up though. I have a 2004 CBR 600RR and in the manual it states 86 octane or higher is the recommended for this bike. With that said if you look in the owner's manual, we should be changing gears every 7miles our so until we get into 6th gear, so basically about 30miles an hour or so in 6th gear is recommended. With that kind of riding, yeah I guess 86 or higher octane is perfect for that application. But who the hell rides like that? If your riding hard like the average joe, than a higher octane gas is recommended in my opinion. Another heads up for you guys and gals. The other day I looked under my back seat, and noticed a sticker with info for my bike. You know info like spark gap size, tire info, and oh yeah octane recommendation. CHECK THIS OUT.... Honda recommends 91 octane for my bike afterall. No sh*t. Check your sticker and let me know if yours has the same thing. I bought my bike in Canada, but that shouldn't make a difference. Ever since I noticed the sticker, I've switched to 91 octane. Bike runs the same as it was with 87 octane to tell you the truth. But I just wanted to go with what the sticker seat said. I just picked the higher number, to make sure because in 2nd gear I'm doing over a hundred, so I just don't feel right using 87. Why would there be a discreptancy from what is stated in the manual and what is stated under the back seat on a sticker? Okay guys you know the drill, go to your back seat and read the sticker, do you see 91 on there? Let me know, and let the forum know this as well. I'd hate to see someone screw up there bike, because they were running 87 when really we should be riding 91 minimum. Just my 2 canadian cents. And no I'm not trying to argue or go against other opinions on here, just reading you the facts, thats all.
#26
10-10-2006 | 12:18 PM
Joined: Oct 2006
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#27
10-10-2006 | 01:30 PM
Senior Member
Joined: Aug 2005
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RE: Octane, Compression Ratio, and Detonation.
well...if you take what abad's thread says and apply it to the numbers...makes perfect sense...but alas, use what you want to make your heart feel good and your head good!
i now only use super duper thug gansta mawfaki octane gasoline that can only be found in the hoods of LA...it's rated like 1000 octane or something...and it really does make my bike go faster!!! why? cause everytime i gas up with this stuff, i get mugged, so in addition to the price of gansta octane gas...which is bling...and the amount of money they take from me...my wallet is so light that just the weight savings alone made my bike go faster! i have tried the same thing at other places, but the thugs there don't take just the right amount of money so power suffers.
i now only use super duper thug gansta mawfaki octane gasoline that can only be found in the hoods of LA...it's rated like 1000 octane or something...and it really does make my bike go faster!!! why? cause everytime i gas up with this stuff, i get mugged, so in addition to the price of gansta octane gas...which is bling...and the amount of money they take from me...my wallet is so light that just the weight savings alone made my bike go faster! i have tried the same thing at other places, but the thugs there don't take just the right amount of money so power suffers.
#30
10-10-2006 | 02:01 PM
Joined: Oct 2006
Posts: 79
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