Power comander ???
Tourer
Joined: Apr 2009
Posts: 282
Likes: 1
From: Las Vegas area
That extra fuel being added is not just getting washed down the exhaust pipes in liquid form. The point of adding more fuel is to create a more powerful explosion, and subsequently create more power.
More power means less rolling of the throttle for the same effect.
Theoretically there should be a point of "optimum" combustion where every bit of "power" is extracted from the fuel/air mix being pumped into the cylinders with no excess fuel and no excess air. Running leaner or richer than that should both negatively impact fuel economy.
The EPA specs are tuning for exhaust emissions, not optimal engine performance. Tuning leaner does not necessarily improve mileage.
More power means less rolling of the throttle for the same effect.
Theoretically there should be a point of "optimum" combustion where every bit of "power" is extracted from the fuel/air mix being pumped into the cylinders with no excess fuel and no excess air. Running leaner or richer than that should both negatively impact fuel economy.
The EPA specs are tuning for exhaust emissions, not optimal engine performance. Tuning leaner does not necessarily improve mileage.
Ultimate HDF Member
Joined: Jan 2009
Posts: 5,016
Likes: 277
From: East Tn Foot of The Dragon
with an o2 sensor motor running reg gas over high grade your mpg will suffer. always run the high grade and carry a bottle of octane booster to use when you can't get the good stuff. a high volume fuel stop is always a good choice, i have read papers over the years that rate fuel quality of major brands and shell has been at the top followed by chevron, phillips 66, mobile, amoco, exxon. aviod the generic cut rate places if possible
The Schlong Man
Joined: Mar 2007
Posts: 3,772
Likes: 4
From: Nantucket
You may be right. I was already at stage 2 with my SE 95" kit so maybe fuel moto's stage 2 programming, while yielding some benefits, does not add noticible performance gains over the HD stage 2 download. Maybe apples and oranges here. Then again maybe I did get a bum unit. Bike still runs very well though. I'm glad I bought the PCV I guess but my bike is no faster (if that what we mean when we say performance gains) than it was before the install. I don't really notice any decline in heat although I guess with my drop in MPG by default I am running cooler internally.
Most report noticeable performance increase, and this should be the result if the PCV is programmed properly. If it is a Fuel Moto purchase it will be properly configured before it leaves their facility, so if you bought yours from them and you didn't notice a performance boost I would give them a call, as that doesn't sound right to me. The HD Stage 1 download does little more than make small changes to match the muffler/AC mods while keeping emissions at EPA specs. A FM-configured PCV is set for maximum cooling and performance.
Last edited by ken thompson; Jun 12, 2009 at 01:06 PM.
Extreme HDF Member
Joined: Sep 2005
Posts: 11,615
Likes: 50
From: Baton Rouge, LA
Theoretically there should be a point of "optimum" combustion where every bit of "power" is extracted from the fuel/air mix being pumped into the cylinders with no excess fuel and no excess air. Running leaner or richer than that should both negatively impact fuel economy.
The EPA specs are tuning for exhaust emissions, not optimal engine performance. Tuning leaner does not necessarily improve mileage.
The EPA specs are tuning for exhaust emissions, not optimal engine performance. Tuning leaner does not necessarily improve mileage.
Leaner does improve mileage up to a point. If you lean excessively (>14.7:1) you may get detonation and a power decrease that becomes counter-productive. Stoichiometry for gas engines is reportedly 14.7:1, but although this works well for most water-cooled vehicles it causes air-cooled engines to run hot. "Stoich" may also be ideal for both in terms of gas mileage.
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Road Captain
Joined: Oct 2006
Posts: 561
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I have never worked on gas engines. But I know in the diesel class 8 trucks when the EPA got involved we leaned them out and changed timeing. We lost both power and mileage. Since they have done other things includeing spraying fuel in the exhaust if you can beleive it to reduce emissions
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Joined: Jun 2009
Posts: 75
Likes: 1
I have never worked on gas engines. But I know in the diesel class 8 trucks when the EPA got involved we leaned them out and changed timeing. We lost both power and mileage. Since they have done other things includeing spraying fuel in the exhaust if you can beleive it to reduce emissions
Seasoned HDF Member
Joined: Dec 2007
Posts: 8,341
Likes: 714
07 ultra added pcv (fuelmoto)intake and slipons. mymilage stayed the same.i think the biggest reason is the motor runs so much better in the lower rpms i can now use 6th gear at lower speeds without pinging and surging and i use less throttle to stay at speed. the afr is noticably ritcher i can smell it on long decels and it is cooler.
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