Pump Gas vs Race Fuel

AllanG

Member
Curious as to the merits of running something like U4.4 over say V-Power?

Currently stock internals, and a full system exhaust.

What point have you experienced noticeable gains in running a race fuel?
 

Arctic Donkey

Active Member
Without tuning it on a dyno you will likely gain very little. Add up how much you would spend on race fuel for a season then take that money and spend it on suspension, motor work or extra track time/lessons.
 

sand.man

Well-Known Member
If you're trying to take entire seconds off your lap times, race fuel isn't the answer... Race fuel is either used in accompany with a tune because it's a much more consistent fuel than pump gas or used where high compression requires it, or both.

It's not poured in just to add horsepower, in other words.
 

411ninja

Member
Shell

I'm going to wager it doesn't make that much difference at the level we are racing. Ian runs premium Shell.
 

DMesher

Active Member
[imagine the theme from Twilight Zone playing in the background, and Rod Serling's voice]

'Imagine if you will... 98 Octane fuel ... no ethanol enrichment ... right out of your corner gas station pumps'

While in Australia I marvelled at the 'petrol' station fuel varieties; Regular Unleaded 91 Research Octane Number (RON), Mid 95 RON and Premium 98 RON.

Although not the (R+M)/2 numbers as are used in NA, there was no ethanol added.


While at Phillip Island, all of the rental bikes were being fueled out of ELF 50 litre sized cans of PERFO 100 with a pump attached. When I asked about the fuel I was told it was 'regular petrol' (not oxygenated race fuel) at 109 RON (103 (R+M)/2). The complaint from the gent doing the fueling was that it was about AUS$9.00/litre rather than the AUS$1.45 at the pump for 98 RON.

All I could think was ...I wonder how much it would cost to import a few cans. :) Maybe I should post under the GROUP BUY section and then see if anyone in the EMRA is in the import/export business.

Darel
 
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Fireman

Well-Known Member
One of the best things about race fuel is that it is a consistent grade. I had some real issues in Calgary in the 2010 nationals when I got bad pump fuel.
 

fast316

EMRA Executive Member
One of the best things about race fuel is that it is a consistent grade. I had some real issues in Calgary in the 2010 nationals when I got bad pump fuel.

Oh suuurrreee, blame it on the gas...jk, anyways, many good points here, especially the one about your wallet.
 

DMesher

Active Member
From a horsepower perspective it is important to try to avoid ethanol enriched gasolines if possible, even if they are higher 'octane'. Ethanol doesn't enriched gas, it actually degrades it.

Alcohols have much lower stored energy, which can be measured in British Thermal Units (BTUs), than gasoline. When alcohols are added to gasoline the resulting product has less stored energy; meaning more throttle (fuel) is required for the same horsepower/speed (also producing lower fuel mileage numbers).

Specifically, ethanol has an energy content of about 76,330 BTU per US gallon (3.78 litre) and regular gasolines have about 114,000 British Thermal Units per US gallon (3.78 litre) depending on brand and formulation etc. A blend of 10% ethanol (E10) will result in a gallon of the mixed fuel having 110,230 BTUs, or a 3.3% decrease in stored energy compared with the pure gasoline component.

The scenario is worse for higher octane blends; premium gasoline has approximately 125,000 BTUs/gallon, and after blending with 10% ethanol produces a mixed fuel with 120,133 BTUs/gallon, or a decrease of 3.9%. Obviously, the performance reduction gets worse for blends using 15% ethanol (E15).

Darel
 

AllanG

Member
Lots of really great information here guys!
And it definitely makes sense that it would be more consistent, but not a guaranteed gain.
And when compared to the "wallet weight savings" I'm surely going to stick to running pump gas for this year.
 

Jason Henton

Active Member
From a horsepower perspective it is important to try to avoid ethanol enriched gasolines if possible, even if they are higher 'octane'. Ethanol doesn't enriched gas, it actually degrades it.

Alcohols have much lower stored energy, which can be measured in British Thermal Units (BTUs), than gasoline. When alcohols are added to gasoline the resulting product has less stored energy; meaning more throttle (fuel) is required for the same horsepower/speed (also producing lower fuel mileage numbers).

Although you are correct in that alcohol has a lower Btu rating per volume, I believe it also has a lower stoichiometric ratio, allowing you to burn more fuel per volume of O2 and thus giving you an increase in released energy. Although I doubt the difference in power of a 10-15% blend is actually relevant to most normal humans, it will have an effect on jetting/fuel mapping and alcohol is known to react negatively with parts of the fuel system (it's corrosive).
 
If you want "pour in power", VP MS109 is great. Just swapping out pump gas for MS109, I saw a 3-4% increase on the the dyno. No tuning required. (Although it did benefit from a few little tweaks)


As for ethanol blends... Ethanol is actually a power adder, when tuned for. Ethanol has that delicious hydroxyl group attached, it's literally an oxygenated fuel. E85 will give you the same gains as race fuel - you just need to ensure the fuel system can cope with the requirements.
 

Goatse

Active Member
From a horsepower perspective it is important to try to avoid ethanol enriched gasolines if possible, even if they are higher 'octane'. Ethanol doesn't enriched gas, it actually degrades it.

Alcohols have much lower stored energy, which can be measured in British Thermal Units (BTUs), than gasoline. When alcohols are added to gasoline the resulting product has less stored energy; meaning more throttle (fuel) is required for the same horsepower/speed (also producing lower fuel mileage numbers).

Specifically, ethanol has an energy content of about 76,330 BTU per US gallon (3.78 litre) and regular gasolines have about 114,000 British Thermal Units per US gallon (3.78 litre) depending on brand and formulation etc. A blend of 10% ethanol (E10) will result in a gallon of the mixed fuel having 110,230 BTUs, or a 3.3% decrease in stored energy compared with the pure gasoline component.

The scenario is worse for higher octane blends; premium gasoline has approximately 125,000 BTUs/gallon, and after blending with 10% ethanol produces a mixed fuel with 120,133 BTUs/gallon, or a decrease of 3.9%. Obviously, the performance reduction gets worse for blends using 15% ethanol (E15).

Darel


This is pretty one sided and misleading IMO.

Sure if nothing is changed in the engine and what controls it, an ethanol based fuel may make less. Buuut..... (big but) if the engine and fuel system are optimized properly then the ethanol based fuel can make more horsepower...

The fuel supply volume would have to be increased and the timing advanced, but it most definitely will not make less power if this is done. The higher octane rating of the ethanol allows for more advanced timing (due to better knock protection), and there is more oxygen in ethanol than gasoline. With the extra oxygen in the ethanol, it has a lower stoich compared to gasoline. With that it has to be run richer than gasoline (more supply), but running the extra volume makes it more than compensate for the lower energy per unit per volume in the end.

So yeah it 'makes' less energy per unit of volume, but the ability to use more of it makes the output higher (and that's not even including the benefit of being able to use extra timing).



That being said... I wouldn't tune a bike on the ragged edge for a pump based ethanol or alcohol based fuel. Strictly for the fact that pump fuels and their ethanol content would not be consistent enough for my liking. But if it was a controlled fuel from a reliable source, I wouldn't hesitate to setup a bike to run it.
 

DMesher

Active Member
This is pretty one sided and misleading IMO.

Sure if nothing is changed in the engine and what controls it, an ethanol based fuel may make less. Buuut..... (big but) if the engine and fuel system are optimized properly then the ethanol based fuel can make more horsepower...

The fuel supply volume would have to be increased and the timing advanced, but it most definitely will not make less power if this is done. The higher octane rating of the ethanol allows for more advanced timing (due to better knock protection), and there is more oxygen in ethanol than gasoline. With the extra oxygen in the ethanol, it has a lower stoich compared to gasoline. With that it has to be run richer than gasoline (more supply), but running the extra volume makes it more than compensate for the lower energy per unit per volume in the end.

So yeah it 'makes' less energy per unit of volume, but the ability to use more of it makes the output higher (and that's not even including the benefit of being able to use extra timing).



That being said... I wouldn't tune a bike on the ragged edge for a pump based ethanol or alcohol based fuel. Strictly for the fact that pump fuels and their ethanol content would not be consistent enough for my liking. But if it was a controlled fuel from a reliable source, I wouldn't hesitate to setup a bike to run it.

Point taken, my comments were made based on NOT specifically tuning an engine to optimize the performance of a specific fuel source.

Using a dyno, designing the compression ratios, air intakes, combustion chambers, peak RPM etc. etc. and tuning an ECU for just about any particular fuel source will maximize performance. This is why unbelievable horsepower outputs are possible on just about any fuel, if engines are set up for them.

There are many excellent references out there (like Colorado State Research on the addition of alcohols to fuel; http://www.ext.colostate.edu/pubs/farmmgt/05010.html), and tons of anecdotal info.

As always, your mileage may vary.

Darel
 
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