ethanol

JeepTherapy

JeepTherapy

New member
Joined
Dec 26, 2005
Messages
533
Age
64
Location
Negaunee
Somewhere I recall reading that I shouldn't run ethanol based fuels in my sled. I ride a stock 04 viper. With the new government mandates that adds ethanol to all gas whats a guy to do?

Or am I just out there somewhere and need to back off the pain pills and just pull up to the pump and have at?
 

just run 89 or 91 octane if you have to run the mix. i have used a few tanks in the past and its fine.
 
Maybe I'm out to lunch here, but I was under the impression that ethanol and oxy blended fuels were simply at a lower octane than pump gas. You can get around this 2 ways. Add a little octane boost or run a little fatter jetting to make up for the lower octane.

I'm sure someone here will chime in here to tell me if I'm wrong.
 
For a given octane test level of regular (non-ethanol) gasoline and a blend of gasoline and ethanol, the octane is the same. The rating is a test method, so what you see for octane number at the pump is what you get. You don't need to increase the octane if you are running an ethanol blend. Ethanol based gas is definately a source of problems in our sleds now, in the way of hardening soft fuel components such as fuel lines, etc.
 
Ethanol has less BTU's then gasoline. So ethanol, or gasoline with ethanol added (oxygenated fuel) requires a richer mixture to produce the same amount of energy as gasoline without ethanol.

This is why you will see a note in some jetting charts, if using oxygenated fuel to go up one or two jet size's. Basicly oxygenated fuel leans out the mixture. It normally dosn't cause a problem if you are jetted for the fuel.

Not sure how much oxygenated fuel you'll see. Part of Bush's plan to reduce the cost of gas, is to remove the emission requirements of gasoline. This allow's the refiner's to stop making oxygenated fuel. The idea is the cost saving's from the cheaper to produce fuel, is suppose to be passed on down to the pump. What I think is going to happen is, the oil companies will pocket the extra profit (like they need more) and just keep on screwing us.
 
I just recalled seeing something in the news last week about gas shortages because of the government requirement to add ethanol and the refineries were not prepaired to meet the deadline.

I went back and read the manual. It says something to the effect that I shouldn't run more than 5% ethanol and if I do run the 5%, run a larger jet size. Typically ethanol is addet at 10%? It also said run 88 octane minimum.... ooops, been runnin 87. Good thingI went for the 4 year warranty plan I guess...

On a side note, I don't drive my sled to the extreame. I don't do long hard pulls (can't hang on) and have not modded it at all.
 
Stock viper is designed to run on regular unleaded. Depending on elevation that could be from 89 to 85 octane. However the higher the octane the less chance of pinging. Any modifications to engine should move to a higher octane.
If you are running a stock sled and run ethanol (15%).....you should increase jet size by one....says yamaha.
 
The 88 octane minimum is for sea level operation. The octane requirement at elevation ( above 4000 ft.) is 85. The higher in elevation, the less air= less octane requirment at least in a auto.
Octane will not produce horse power.....it only helps with pre-ignition.
I ride at 5000-10,000ft. and always use 91 octane just to be on the safe side if I happen to be a little on the lean side when traveling from lower elevations to the higher elevation where I will be spending most of my time. A lot of parking areas are quite abit lower than where I guy may spend most of his time riding.
In the snowies I unload at 7500 ft. but spend most of my time riding at 9000 ft. and higher. Who wants to stop half way up and change jets.
Don,t bring up the idea of a compensator......they don,t work at that elevation.......ask skidooboy.
 
snomoguy said:
The 88 octane minimum is for sea level operation. The octane requirement at elevation ( above 4000 ft.) is 85. The higher in elevation, the less air= less octane requirment at least in a auto.
Octane will not produce horse power.....it only helps with pre-ignition.
I ride at 5000-10,000ft. and always use 91 octane just to be on the safe side if I happen to be a little on the lean side when traveling from lower elevations to the higher elevation where I will be spending most of my time. A lot of parking areas are quite abit lower than where I guy may spend most of his time riding.
In the snowies I unload at 7500 ft. but spend most of my time riding at 9000 ft. and higher. Who wants to stop half way up and change jets.
Don,t bring up the idea of a compensator......they don,t work at that elevation.......ask skidooboy.
Click to expand...

My Variflow has worked flawless since 1999, 1200ft up to the Snowies(9000ft+).I would not own a Yammi without one. ;):D
 
I ride at like 150ft or so.... get light headed in the nose bleed seats ;D I guess I was a little concerned about corrosion or something being an issue. I had the manual out last night on line, that was where I got the 88 octane requirement. Now my brother in law tells me that regular unleaded where he is at is 85 octane, here it is 87. I am in the UP, thus the low elevation. I don't think I have a detonation, or even had had a detonation issue. Not sure how you would ever tell if you did without a teardown?
 
snomoguy said:
Don't get me started on those piece of sh#@ variflows, attacc.
You guys are lucky!!!!
Click to expand...

Everybody that I know with a Yammi has a Variflow. None of them have ever had any grief. ;):D
 
snomoguy said:
Don't get me started on those piece of sh#@ variflows, attacc.
You guys are lucky!!!!
Click to expand...


pipe your sled, rejet incorrectly (mid and or high range), peel head gasket layers and or alter porting,,,,, all are recipe for engine disaster if you are not expert at tuning....

put a compensator on a stock sled and jet safely (mid and high range) with prudent baseline and they will perform very well...

run ethanol and jet appropiately (mid and high range) with a compensator and they still perform well.

not a tuner by any stretch, merely have learned to respect, drop in ambient temps, drop in elevation, higher percent oxygenated fuels (ethanol) and or rises in barometric pressure...



luck, has little to do with it.....
 
Last edited:
You must log in or register to reply here.


Back
Top