Let's talk octane and ethanol - snow bikes

[dirtnerd]

So what octane are you guys running in your snow bikes? and do you avoid ethanol in your gas?

I ask because I have heard two stories recently.

1) some guys in canada are not seeing the power gains with some after market ECUs and some guys are claiming it's because the ECUs were tuned with sometimes 30% ethanol in the gas. This is interesting because for dirt bikes, boats, everything toy related we avoid ethanol like the plague. In Canada and specifically in BC most of our gas has at most 10% ethanol, the pumps say "may contain up to 10%" some people have mentioned to me that when prices are out of whack they sometimes don't put any in at all.

2) Just recently riding with a buddy in the mountains and he mentioned that he and his other riding buddies have switched to 87 octane pump gas (which has the may contain up to 10% ethanol). He says his bike has never run better. This is interesting because we are always running these bikes in cold temps at altitudes above 5000 feet. So pre-detonation may not be a problem.

 

[Ben 500RR-S]

I've been running both E-10 and non-ethanol in my dirt/snowbike this past winter and have found no difference. I know better than to run 91+ as my bike has no need for it at all.

We've had nothing but E-10 here since 2005 or so and I've had NO problems with running it in any of my stuff, dirtbikes, motorcycles, boat motors, snowmobile. It doesn't concern me one single bit.

 

[skidooboy]

90 octane rec fuel, non ethanol, in EVERYTHING BUT, THE CARS, TRUCKS. no more issues at all. Ski

 

[powdermuncher]

Yes E10 has one month shelf life , after that your just guess on octane. None ethanol 91 about 3 month ad sea foam for any stored gasoline even if it is only a few weeks. If you just buy it and burn it right away from a high volume gas station it usually does not matter much what you burn. Anything over 5000 feet and you are down on power by somewhere in the neighbourhood of 15% deto should be a none issue on stock equipment.

 

[rhino89523]

I run non eth as much as possible in everything that sits around at all. There are not that many places to get it around us so I stock up when I can. The place I get it does 91 so I run that in everything but my sand bike because that one has a bunch of port work, head work and when we built it we built it for race gas.

I don't worry too much about the octane, it's more just what that eth does. It doesn't store well at all so if you don't use something for a while it will be all gummed up or burn out the rubber lines. I have a bunch of old cars (mostly Internationals) and a motorhome, a sandrail and a boat...those don't get used all the time. Non eth with a little seafoam means no gummed up fuel parts turn the key and go.

 

[wwillf01]

Really depends on altitude.. I know we are at around 5500 in the valley and then ride 8000 and up so 88 non ethanol makes more power on the dyno than using 100 octane race fuel.. At then end of the day you need to pick the fuel for you set up.... Compression, altitude ect.... I have never found anything good in ethanol.... Yes you can get more power on a dyno (If tuned for it) but the trade off is not worth it on shelf life to me...

So what octane are you guys running in your snow bikes? and do you avoid ethanol in your gas?

I ask because I have heard two stories recently.

1) some guys in canada are not seeing the power gains with some after market ECUs and some guys are claiming it's because the ECUs were tuned with sometimes 30% ethanol in the gas. This is interesting because for dirt bikes, boats, everything toy related we avoid ethanol like the plague. In Canada and specifically in BC most of our gas has at most 10% ethanol, the pumps say "may contain up to 10%" some people have mentioned to me that when prices are out of whack they sometimes don't put any in at all.

2) Just recently riding with a buddy in the mountains and he mentioned that he and his other riding buddies have switched to 87 octane pump gas (which has the may contain up to 10% ethanol). He says his bike has never run better. This is interesting because we are always running these bikes in cold temps at altitudes above 5000 feet. So pre-detonation may not be a problem.

 

[Jaynelson]

In Canada and specifically in BC most of our gas has at most 10% ethanol, the pumps say "may contain up to 10%" some people have mentioned to me that when prices are out of whack they sometimes don't put any in at all.

In the regular, yes.

Other than Husky/Mohawk, most of the big-brand gas (Esso, Chevron, Gas Bar, Shell, etc) in BC has 0 ethanol in the premium fuel (91 octane and higher).

 

[dirtnerd]

In the regular, yes.

Other than Husky/Mohawk, most of the big-brand gas (Esso, Chevron, Gas Bar, Shell, etc) in BC has 0 ethanol in the premium fuel (91 octane and higher).

indeed

 

[Norma Stitz]

Most of us use pure 92 here but it’s true that higher octane has less inherent energy potential than lower “grades”. Also I feel the fears of storage times are sometimes exaggerated. I’ve used much older gas than a few weeks and it smelled and worked fine. You can also get airplane fuel 100octane low lead at any airport. They won’t put it into your car or boat but they will happily fill your jugs.

 

[rhino89523]

With the Eth fuel its not the smell of it being old and it's not so much the time of storage. The stuff is hydroscopic, so depending on your environment it could degrade at different rates, but having fuel that basically attracts moisture out of the air is not a good thing for storage. Boats have those Diaper style fuel filters that will goo out with water in them and your boat will run like crap....nothing really loves to run on water.

 

[Jaynelson]

Unless there are dyno numbers agreeing with this, I wonder if there is a 2nd phenomenon at play here that's nothing to do with fuel...

Over the years of riding sleds and dirt bikes, and being in the biz.....I've always noticed that BC guys who live and ride in the mountains, often get a lot less jazzed about the benefits of modifications than people from other areas. I know very few people who will dedicate much time to testing mods....and the reality is, if you are not paying much attention to the nuances of the machine pre/post mod.....most of the stuff is not a night/day difference. There are a lot of skilled riders per capita (of anything....bikes, sleds, skis, etc), and if you are looking for mods to help you keep up, it won't work.

I've had a few dirtbikes over the years....I never knew they needed uncorked this or modded that until I looked it up on the net. Often after doing the mods that seemed to be the "holy grail" on the internet, I was disappointed at the real world gains. Mods or no mods, the primary objective of the ride was still the same....keep up and don't wad yourself. As the ECU is an expensive piece, I would bet you are seeing a bit of this.

 

[rhino89523]

For me I don't care at all about Dyno numbers or power from the fuel. My dirtbike is a 500 af, I could probably lengthen the throttle cable by a half inch and it would make no difference, I never twist it to the lock. On everything I own for the most part I leave the motors stock because once you mess with one thing you have to mess with everything and I'm more into using it than tinkering with it during the time I would rather use it. My sand bike is the only exception and it is the dunes...not exactly the kind of riding that takes skills.

It's the storage of fuel in stuff. That eth eats rubber and pulls the water out of the air and attaches to your fuel...want to have a fun first day of use with your boat? leave it sitting with eth fuel in it untreated for 6 months and guaranteed you will have the cover off more than you are surfing. Want to ruin a carb? get one with a plastic float and give it a couple years in eth fuel and you will find chunks of it somewhere in there.

I don't mod things like dirtbikes to try and keep up, you either do or don't. ultra fast pro guys I have ridden with like Shane Esposito will smoke me on a Z50. I'll smoke Shane if he leaves a tank of eth sitting in his bike for 8 months.

 

[Jaynelson]

For me I don't care at all about Dyno numbers or power from the fuel. My dirtbike is a 500 af, I could probably lengthen the throttle cable by a half inch and it would make no difference, I never twist it to the lock. On everything I own for the most part I leave the motors stock because once you mess with one thing you have to mess with everything and I'm more into using it than tinkering with it during the time I would rather use it. My sand bike is the only exception and it is the dunes...not exactly the kind of riding that takes skills.

It's the storage of fuel in stuff. That eth eats rubber and pulls the water out of the air and attaches to your fuel...want to have a fun first day of use with your boat? leave it sitting with eth fuel in it untreated for 6 months and guaranteed you will have the cover off more than you are surfing. Want to ruin a carb? get one with a plastic float and give it a couple years in eth fuel and you will find chunks of it somewhere in there.

I don't mod things like dirtbikes to try and keep up, you either do or don't. ultra fast pro guys I have ridden with like Shane Esposito will smoke me on a Z50. I'll smoke Shane if he leaves a tank of eth sitting in his bike for 8 months.

Who's arguing that ethanol fuel doesn't have detriments? The question was if the use of NON-ETH premium up here is causing performance loss with ECU's that may be tuned for fuel with ETH in it (as that is all that's available in some areas). Typically....anything tuned FOR ethanol fuel will have richer fuel mapping, so it's a legit question.

That said, I don't think there's enough of a difference either way to make much of a performance difference....hence my alternate theory as to why " some guys in canada are not seeing the power gains with some after market ECUs"

 

[rhino89523]

Who's arguing that ethanol fuel doesn't have detriments? The question was if the use of NON-ETH premium up here is causing performance loss with ECU's that may be tuned for fuel with ETH in it (as that is all that's available in some areas). Typically....anything tuned FOR ethanol fuel will have richer fuel mapping, so it's a legit question.

That said, I don't think there's enough of a difference either way to make much of a performance difference....hence my alternate theory as to why " some guys in canada are not seeing the power gains with some after market ECUs"

Got it...makes total sense. I think genetics may have played a factor in my comprehension ie im a Dumbass

 

[needpowder]

So are you saying that you think the race bikes come stock tune for ethanol? Or that you guys are running aftermarket ECUs that are tuned for ethanol? Either way neither one makes any sense for me. I can’t imagine that factory race bikes come tuned for 91 with ethanol in it. And I’m pretty sure my PR to doesn’t come with the ethanol map.
I don’t have any information on the performance difference because I will never run anything with ethanol anything but my lawnmower .

 

[powdermuncher]

Ethanol has a less BTUs per litre than straight gasoline, so if you have the same map in theory you are running leaner. Combine this with power loss at altitude ( less air - less pressure in the combustion chamber) requires less octane so in theory you are at a hotel state of tune with regular E10.
Higher octane will have a slightly slower burn rate (slower moving Flame front) . So if you are Mr super tuner you could probably massage 1 or 1.5 extra HP by Leaning out and advancing the timing a bit for the same result on 91 octane straight fuel. Then again when I am wide open flirting with the rev limiter all day I am just fine with the extra safety margin on my motor. Most Guys would be well advised to ride more than to worry about fractions of HP. Now if you wonder why the BC guys don't mod as much as others--Maybe they ride more.
Oh and 3-4 feet of pow in steep terrain will let you know real fast if your mods are reliable

 

[n16ht5]

The ethanol will allow the ecu to run at a more advanced timing than non-eth fuel. RAZE ecu's won't work well if you don't run E10 fuel

 

[Misha Subo]

Please explain.

Can someone demystify the whole octane vs methanol issue?

I'm always reading controversial articles on this and it seems everyone has their own take on what's best. I've got the 300 XCW carb paired with a Camso running at almost sea level and often -F temps (Southern Ontario). What should we be looking for at the pumps and should it be the same in the summer, and why?

 

[powdermuncher]

The ethanol will allow the ecu to run at a more advanced timing than non-eth fuel. RAZE ecu's won't work well if you don't run E10 fuel

Wrong -- Octane will allow to run at more advanced timing.

Ethanol is but one way to get the necessary octane into Gasoline -- So is Methyl Ethyl Lead or Toluene.

At the end of the day it is simply octane that Matters!
But -- if you make 88 octane by using alcohol you have less Btu per litre or Gallon and run slightly leaner. In General that amounts to less power. Now if the RACE ECU is set up specifically for E10 it will add extra fuel to make up for E10 lower BTUs. I would suggest I can do exactly the same thing with the Yamaha tuner if I would be so inclined. I rather run good fuel and a slightly leaner more advanced ignition curve.

 

[chumbilly1]

So are you saying that you think the race bikes come stock tune for ethanol? Or that you guys are running aftermarket ECUs that are tuned for ethanol? Either way neither one makes any sense for me. I can’t imagine that factory race bikes come tuned for 91 with ethanol in it. And I’m pretty sure my PR to doesn’t come with the ethanol map.
I don’t have any information on the performance difference because I will never run anything with ethanol anything but my lawnmower .

The RAZE wingman ECU is designed to run on E-10. They do not have the different maps that PR2 offers. No idea why they require E-10, but I dont build my own maps either, for a reason! I nail dead trees together for money and then spend it on go fast $hit