MotoHouston.com MotoHouston.com
Register Members List Member Map Media Calendar Garage Forum Home Mark Forums Read

Go Back   MotoHouston.com > Technical > How To's and Q & A's
Forgot info?

Welcome to MotoHouston.com! You are currently viewing our forums as a guest which gives you limited access to the community. By joining our free community you will have access to great discounts from our sponsors, the ability to post topics, communicate privately with other members, respond to polls, upload content, free email, classifieds, and access many other special features. Registration is fast, simple and absolutely free, join our community!

Register Today!

If you have any problems with the registration process or your account login, please contact us.


Like us on Facebook! Regular shirt GIVEAWAYS and more

Advertisement

Reply
Share This Thread: 
Subscribe to this Thread Thread Tools
Old 10-16-2009, 11:54 AM   #21
SpeedCheeser
and whiskey
 
SpeedCheeser's Avatar
 
Join Date: Mar 2009
Location: Houston - Med Center
Feedback Rating: (0)
Posts: 8,550

Experience: 2 years
Trackdays: 1

Bike(s):
thieves









Quote:
Originally Posted by switch View Post
i run 87 in the bike, its cheaper. /thread.
What's the manual recommend? I think it's supposed to be 87 on a 650r, in which case you're doing the right thing.

Quote:
Originally Posted by Irak View Post
I was asking because almost all my vehicles state that, per instance the A4; the R6 and the WR250X state in the owners manual that you should use above 91 octane gas.
In Mexico when I had my 06 CBR600RR the manual said the same, I ran 87 octane and the bike worked really good, in fact as someone said it felt better than using 91.
Aren't all of those cars turbocharged? I think every turboed car requires 91+, due to the extra compression from the turbo.
__________________
avatar44755 2
Quote:
Originally Posted by eltejano View Post
I always thought speedcheeser was a meth head with a fondness for dairy products.
Quote:
Originally Posted by Sifu-TZ View Post
he's a viking accountant. he looks at the bottom line, then he yells at it.
SpeedCheeser is offline   Reply With Quote
Similar Topics
Thread Thread Starter Forum Replies Last Post
Did I really get 93 octane? Track_Graphics General Discussion (Moto Related) 85 08-10-2014 03:30 PM
Is 93 Octane better to use? MotoMonkey General Discussion (Moto Related) 70 04-19-2012 08:14 AM
USING OCTANE BOOT GXRPrincess General Discussion (Moto Related) 6 02-01-2010 06:52 PM
What are the Octane Requirements..... TxBritt08R1 General Discussion (Moto Related) 10 07-03-2007 08:13 AM
What octane fuel do you use?? loewer600 How To's and Q & A's 54 12-21-2006 05:51 PM
Advertisement
Old 10-16-2009, 11:57 AM   #22
bumblebee
Yeah I'm flippin' YOU off
 
bumblebee's Avatar
 
Join Date: Oct 2006
Location: Pearland
Feedback Rating: (3)
Posts: 12,268


Bike(s):
'74 Suzuki GT380
'82 XS650 StreetTracker
'10 Ducati Streetfighter
'83 Yamaha Seca 900






Quote:
Originally Posted by Irak View Post
I was asking because almost all my vehicles state that, per instance the A4; the R6 and the WR250X state in the owners manual that you should use above 91 octane gas.
In Mexico when I had my 06 CBR600RR the manual said the same, I ran 87 octane and the bike worked really good, in fact as someone said it felt better than using 91.
Many times the reccomendation to use higher octane gas is a liability hedge on the part of the vehicle maker.
Your bike ran well on lower octane gas because it burns better and your ECU could compensate for the difference. You were risking detonation but as long as it doesn't happen too much, the risk is low.
__________________
Asphalt is for racing... dirt is for growing potatoes. - J. Diester
When seconds count... the police are only minutes away.
Grow up and be a productive member of society already.
Bevo- "I lack skillz"
bumblebee is online now   Reply With Quote
Old 10-16-2009, 12:01 PM   #23
bumblebee
Yeah I'm flippin' YOU off
 
bumblebee's Avatar
 
Join Date: Oct 2006
Location: Pearland
Feedback Rating: (3)
Posts: 12,268


Bike(s):
'74 Suzuki GT380
'82 XS650 StreetTracker
'10 Ducati Streetfighter
'83 Yamaha Seca 900






Quote:
Originally Posted by SpeedCheeser View Post
Yeah, I think most (if not all) newer cars can tell when you cheap out on gas and lower the performance of a car. If the computer doesn't understand that you're using a lower octane fuel, you risk detonation.
The computer doesn't "understand" what gas you are using. In the case of a car, there are detonation sensors which tell the ECU to reduce performance when they sense a problem.
On many bikes there are no detonation sensors so, if your hear the tell tale clatter, you're gonna have a problem soon. If you don't correct the issue.
__________________
Asphalt is for racing... dirt is for growing potatoes. - J. Diester
When seconds count... the police are only minutes away.
Grow up and be a productive member of society already.
Bevo- "I lack skillz"
bumblebee is online now   Reply With Quote
Old 10-16-2009, 12:01 PM   #24
urbanXJ
erect engorged member
 
urbanXJ's Avatar
 
Join Date: Dec 2008
Location: Pearland
Feedback Rating: (0)
Posts: 16,516

Experience: 9 years
Trackdays: 10+

Bike(s):
2008 Versys









my bike owners manual specifically says only 87 octane, and higher octane may result in damage
__________________
Quote:
Originally Posted by gixxerbill View Post
"... I say the govt puts something in the water that sterilizes all women..."
urbanXJ is offline   Reply With Quote
Old 10-16-2009, 12:32 PM   #25
07SLVRCBR
October '08 BOTM
 
Join Date: Jan 2008
Location: Friendswood
Feedback Rating: (4)
Posts: 4,064

Experience: 1-3 months

Bike(s):
2007 CBR1000RR









Quote:
Originally Posted by Irak View Post
In Mexico when I had my 06 CBR600RR the manual said the same, I ran 87 octane and the bike worked really good, in fact as someone said it felt better than using 91.
You should run the LOWEST possible octane without experiencing detonation. Any engine will run most efficiently this way.

Especially in the high-rpm motors, such as motorcycles, the higher octane (slower burning) is not better.
__________________
Support your site sponsors!!

See ya @ the track!
07SLVRCBR is offline   Reply With Quote
Old 10-16-2009, 01:31 PM   #26
didimao0072000
Senior Member
 
didimao0072000's Avatar
 
Join Date: Jun 2007
Location: Midtown
Feedback Rating: (0)
Posts: 746


Bike(s):
50cc metropolitan









Quote:
Originally Posted by bluewave18 View Post
I think there is still plenty of time for it to occur.
my bad.. i meant pre detonation..
didimao0072000 is offline   Reply With Quote
Old 10-16-2009, 01:39 PM   #27
07SLVRCBR
October '08 BOTM
 
Join Date: Jan 2008
Location: Friendswood
Feedback Rating: (4)
Posts: 4,064

Experience: 1-3 months

Bike(s):
2007 CBR1000RR









Quote:
Originally Posted by didimao0072000 View Post
my bad.. i meant pre detonation..
Could you explain "pre detonation?"
__________________
Support your site sponsors!!

See ya @ the track!
07SLVRCBR is offline   Reply With Quote
Old 10-16-2009, 01:40 PM   #28
SBAtdijetta
Turbo Nut
 
SBAtdijetta's Avatar
 
Join Date: Oct 2009
Location: Cypress
Feedback Rating: (3)
Posts: 253

Experience: 5 years

Bike(s):
08 CBR1000RR - Sold
12 VROD NRS - Sold








Quote:
Originally Posted by bumblebee View Post
I did a little more poking around and found that it could be true that high octane gas may pose some risk for lower performance engines.
It turns out that the higher the octane number, the more heavy hydrocarbons are present in the gas. The heavy hydrocarbons can form "gum" deposits in the intake, intake valves and cylinder walls. If these deposits form on the surface of sensors used by the fuel injection system to control fuel/air mixture they can cause the engine to run lean. That could lead to detonation and bent rods, etc.
The gum deposits in the cylinder can lead to "hot spots" which can disrupt smooth combustion, also leading to detonation.

This is less of a problem now because of new additives to prevent the gum deposits, but it could still happen. A high performance engine that requires high octane fuel doesn't suffer as much from these deposits.
This could be especially true for newer cars that are DI (direct injection) motors. The valves really gunk up in DI motors.
SBAtdijetta is offline   Reply With Quote
Old 10-16-2009, 01:50 PM   #29
07SLVRCBR
October '08 BOTM
 
Join Date: Jan 2008
Location: Friendswood
Feedback Rating: (4)
Posts: 4,064

Experience: 1-3 months

Bike(s):
2007 CBR1000RR









Quote:
Originally Posted by SBAtdijetta View Post
This could be especially true for newer cars that are DI (direct injection) motors. The valves really gunk up in DI motors.
Run some leaded 100 octane through every now and again (I'd mix it 50/50). Clean it right up.
__________________
Support your site sponsors!!

See ya @ the track!
07SLVRCBR is offline   Reply With Quote
Old 10-16-2009, 02:03 PM   #30
didimao0072000
Senior Member
 
didimao0072000's Avatar
 
Join Date: Jun 2007
Location: Midtown
Feedback Rating: (0)
Posts: 746


Bike(s):
50cc metropolitan









Quote:
Originally Posted by SBAtdijetta View Post
This could be especially true for newer cars that are DI (direct injection) motors. The valves really gunk up in DI motors.
Quote:
Originally Posted by 07SLVRCBR View Post
Run some leaded 100 octane through every now and again (I'd mix it 50/50). Clean it right up.
how would this benefit a DI engine? 100 octane has no more "cleaning" power than other octane levels. Also, the issue with DI valves gunking up is because the air fuel mixture no longer goes through the intake valve. Only air goes through the intake valve. No remedy that involves gasoline is going to solve that..
didimao0072000 is offline   Reply With Quote
Old 10-17-2009, 10:42 AM   #31
Skid
Senior Member
 
Skid's Avatar
 
Join Date: Dec 2006
Location: Houston
Feedback Rating: (0)
Posts: 777

Trackdays: 10+

Bike(s):
CBR600RR









I see a lot of people refering to the 91 octane rating. This is kinda misleading as it is mostly used overseas. If you look, most bikes claim they need 91 MON (Motor Octane Number) octane rating. Pumps here in the US use the PON (Pump Octane Number) which is based on the formula (RON+MON)/2. This means that a engine requiring a 91 MON should be runing around 87 PON. I hope this info helps.
__________________
Skid
__________________
www.D1-Racing.com

"When you do things right, people won't be sure you've done anything at all."
Skid is offline   Reply With Quote
Old 10-17-2009, 11:29 AM   #32
burnboy
upliftmofopartyplan
 
burnboy's Avatar
 
Join Date: Mar 2008
Feedback Rating: (0)
Posts: 3,609

Experience: 5 years

Bike(s):
2011 kawi z 1000









the whole country (usa) west of abilene texas uses 91 octane as their high or premium. we are lucky to have 93 here. i have a 91 octane, 93 octane, 100, and 104 octane maps in my ecu. just incase i have to go west, i can switch maps for the proper fuel. as my car make almost 30 lbs of boost on the street. if i did'nt have a map for 91 and i had to go even to west texas i would be screwed. and yes the direct injection motors fire the fuel injector directly into the combustion chamber therefore no fuel spraying the back of the valve to clean the valves. therefore they build up gunk on the valve stems and backs of the valves. usually causing misfires. as im aware only german cars use direct injection? maybe and domestic now? i dunno
__________________
f,f&f 4 ever R.I.P. coach dave

Last edited by burnboy; 10-17-2009 at 11:31 AM.
burnboy is offline   Reply With Quote
Old 10-17-2009, 11:31 AM   #33
AJFLo
Senior Member
 
AJFLo's Avatar
 
Join Date: Jun 2008
Location: West Side
Feedback Rating: (8)
Posts: 8,621

Experience: 1-3 months
Trackdays: 1

Bike(s):
K7 GSXR 600
06 Honda 50





I guess I should've run 87 octane on my bike then
__________________
sigpic6669 2
Quote:
Originally Posted by Gixxer-Joy View Post
Iím really happy for you and Iím going to let you finish but AJFlo is one of the baddest mother fockers of all time!!!
AJFLo is offline   Reply With Quote
Old 10-17-2009, 12:07 PM   #34
humanrace911
Member
 
Join Date: Nov 2007
Feedback Rating: (0)
Posts: 41












Quote:
Originally Posted by 07SLVRCBR View Post
Could you explain "pre detonation?"
I believe that pre ignition and detonation have been used incorrectly in this thread.

When an engine charge ignites before the spark (dieseling) that is called pre ignition and the result is the engine has to compress an explosion. Very bad. It is ususally caused by high compression with low octane fuel or a hot spot in the cylinder. One engine I tore down had negative valve clearance on 2 exhaust vavles. The valves never touched the head which is the way they are designed to cool off. Massive damage on both pistons that had bad clearances. Sometimes, but not always, pre ignition can be stopped by advancing timing. Beware, advancing timing may cause detonation.

Detonation is when the charge ignites normally and the flame spread, starting at the spark plug, further compresses and heats the the charge at the edge of the cylinder until all remaining charge reaches a critical point and suddenly explodes. This usually causes damage to the outer edges of the piston. Sometimes it isn't discovered until the added heat melts the outer edge of the piston and causes the rings to stick, resulting in low compression and hard starting.

Retarding ignition will usually stop detonation and some ECUs do just that. Detonation can also be stopped by increasing RPM. The flame spread takes a certain amount of time. If the piston can get further down the cylinder before flame spread can increase pressure to the critical point, then detonation will not happen.
humanrace911 is offline   Reply With Quote
Old 10-17-2009, 12:18 PM   #35
humanrace911
Member
 
Join Date: Nov 2007
Feedback Rating: (0)
Posts: 41












I should have stated in my previous post that Detonation always happens after top dead center (TDC) because engines are designed to have peak cylinder pressure at 12-16 degrees after TDC. Pre ignition always happens before TDC.
humanrace911 is offline   Reply With Quote
Old 10-17-2009, 04:45 PM   #36
burnboy
upliftmofopartyplan
 
burnboy's Avatar
 
Join Date: Mar 2008
Feedback Rating: (0)
Posts: 3,609

Experience: 5 years

Bike(s):
2011 kawi z 1000









which is why the piston crown usually breaks arund the edges of the piston. not through the middle.
__________________
f,f&f 4 ever R.I.P. coach dave
burnboy is offline   Reply With Quote
Old 10-17-2009, 09:33 PM   #37
humanrace911
Member
 
Join Date: Nov 2007
Feedback Rating: (0)
Posts: 41












Because detonation happens around the edges of the piston as the flame travel spreads from the spark plug out. Pre ignition can start anywhere there is a hot spot. Either can cause a hole in the middle of the piston. Engine design has a lot to do with where the "hole" happens.
humanrace911 is offline   Reply With Quote
Old 10-21-2009, 04:19 PM   #38
SBAtdijetta
Turbo Nut
 
SBAtdijetta's Avatar
 
Join Date: Oct 2009
Location: Cypress
Feedback Rating: (3)
Posts: 253

Experience: 5 years

Bike(s):
08 CBR1000RR - Sold
12 VROD NRS - Sold








Quote:
Originally Posted by didimao0072000 View Post
how would this benefit a DI engine? 100 octane has no more "cleaning" power than other octane levels. Also, the issue with DI valves gunking up is because the air fuel mixture no longer goes through the intake valve. Only air goes through the intake valve. No remedy that involves gasoline is going to solve that..
You are right, you can seafoam or pull the motor apart... about all I know to do and they are both a pain IMHO.

Quote:
Originally Posted by burnboy View Post
the whole country (usa) west of abilene texas uses 91 octane as their high or premium. we are lucky to have 93 here. i have a 91 octane, 93 octane, 100, and 104 octane maps in my ecu. just incase i have to go west, i can switch maps for the proper fuel. as my car make almost 30 lbs of boost on the street. if i did'nt have a map for 91 and i had to go even to west texas i would be screwed. and yes the direct injection motors fire the fuel injector directly into the combustion chamber therefore no fuel spraying the back of the valve to clean the valves. therefore they build up gunk on the valve stems and backs of the valves. usually causing misfires. as im aware only german cars use direct injection? maybe and domestic now? i dunno
Where do you get 100 around here btw? (NW or central). Taking my car to the dyno/track this weekend and want to pick up some race fuel.

Yea German cars VW/Audi 2.0T's etc., Mazda has DI 2.0 & 2.3L that I know of making some pretty good power too. Both have been on our shores for a while. I'm sure there are others too.
__________________
When seconds count, the cops are just minutes away. It is better to be judged by 12 than carried by 6.
SBAtdijetta is offline   Reply With Quote
Reply


Thread Tools

Advertisement


All times are GMT -5. The time now is 07:54 AM.


MotoHouston.com is not responsible for the content posted by users.
Privacy Policy