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11/3/2014
Location
Charlotte, MI
US
Edited Date/Time
4/2/2015 9:29am
Has anyone used the new VP T2 fuel for their two stroke? Curious how it runs and how much it costs.
http://racerxonline.com/2015/01/12/vp-releases-pre-mixed-t2-fuel
http://racerxonline.com/2015/01/12/vp-releases-pre-mixed-t2-fuel
I find that to be a little odd considering the octane level is much lower. I was running VP110 straight in my KX250 and thought that there was no way I would tell a difference to C12. So I did a little experiment....and, the Answer is yes you can tell a difference much to my wallets disappointment!
http://www.procircuit.com/jetting-specs.htm
For two-stroke bikes, our jetting specs are for VP Racing C12 Racing Fuel at 0-1500 ft altitude, 70-85 degrees temperature, 32:1 pre-mix oil ratio. We recommend Maxima Castor 927 High Performance 2-Cycle Oil.
The Shop
Mix it fresh each ride
Shake it well
Don't let it sit
Mix small batches
Etc
Specific Gravity: .732 @ 60°F
Color: Pale Green
MON: 101
R+M/2: 105
RON: 109
RVP: 8.5
Leaded: Yes
Pre-mixed: 40:1
Oxygenated: Yes
Oxidation Stability (min.) 1440+
Distillation:
10% evap @ TBD°F
50% evap @ TBD°F
90% evap @ TBD°F
E.P. @ TBD°F
Production: Elmendorf, Texas USA
Availability: Sealed Drums
Rev 1/15
Is this separation issue what I think it is, or is there some kind of chemical breakdown that I am unaware of and this is a bad practice?
I normally use Renegade SX2 which is also .717 gravity.
Any premix, a quick shake, you're good for piece of mind.
People are either lazy or dumb. Or both. But hey, thats why cars have tire pressure monitoring systems. People are too fuckin dumb to operate a pencil gauge.
Specific Gravity - What Is It And Why Does It Matter?
Definition: specific gravity (noun) - the ratio of the density of any substance to the density of some other substance taken as standard, water being the standard for liquids and solids, and hydrogen or air being the standard for gases.
For fuels, specific gravity can be determined by dividing the density of the fuel (in units of pounds per gallon) by the density of water (8.325 pounds per gallon). Let’s look at one example.
Sunoco Supreme weighs 5.95 pounds per gallon. Applying some math: 5.95 / 8.325 = 0.715. So Supreme has a specific gravity of 0.715.
If Fuel A has a lower specific gravity than Fuel B, Fuel A is said to be “lighter” than Fuel B. Literally, a gallon of Fuel A weighs less than a gallon of Fuel B. Sunoco Standard has a specific gravity of 0.728, so it is said to be “heavier” than Supreme.
Why does this matter? Well there are two reasons.
First, specific gravity has an impact on fuel metering, especially for carbureted engines. A heavier fuel is of course denser, so the float in a carb’s float bowl will sit higher than if a lighter fuel was used. If the float sits higher, the fuel level will be lower. Fuel level affects fuel metering in a number of ways, so if you’re switching fuels, pay attention to the fuel level in the bowls.
For most race fuels, specific gravity is also an indication of the composition. Note that the words “most” and “indication” were used – there are exceptions. However, for most race fuels, a lower specific gravity suggests a faster-burning fuel, while a higher specific gravity suggests a fuel is slower-burning. This is because most light hydrocarbons used to make a race fuel are faster burning than most heavier hydrocarbons. This matters because faster-burning fuels usually require less spark advance than slower-burning fuels.
So in addition to paying attention to fuel metering changes when switching race fuels, you need to pay attention to ignition timing as well. We’re not talking huge changes here, but these changes are important to the proper tuning and consistent performance of your race engine.
One final thought – there are implications for pump gas as well. The specific gravity of pump gas will typically range from about 0.720 to 0.770. As you can now guess, this wide range is a reflection of the wide ranging composition. Pump gas composition varies by octane, by region, and by season. For these reasons, a race engine that can run on pump gas must be tuned conservatively just to prevent engine failure. You can imagine the consequences of an engine that is tuned to the ragged edge on one batch of pump gas, then another batch is used in a race and the motor runs lean and timing is over-advanced. Not good.
One of the most important attributes of a race fuel is its consistency. Even if you don’t need all the engine protection offered by a high octane race fuel, you may need its consistency. Specific gravity is one of the many parameters we monitor to ensure quality and consistency in all our fuels, batch after batch.
http://www.racegas.com/article/26
Sunoco 110
Specific Gravity 0.72
100LL (Avgas)
Specific Gravity 0.67
VP C12
Specific Gravity .717
Renegade SX2
Specific Gravity .717
VP U4.4
Specific Gravity .763
Beyond Octane
Overheard at the local track:
“High octane fuels burn slower.”
“My motor doesn’t need all that octane so that fuel won’t do me any good.”
“I need the highest octane so I can max out my timing.”
Unfortunately, those statements are not always true. As a matter of fact, those statements only have some merit in the street gas world where 93 octane fuel is king and 87 is used by most. In the world of racing gasolines where higher octane choices abound, sharp engine builders and racers know they need to look beyond octane to find the right fuel.
But before we ignore octane, it’s important to look at how octane is measured in the first place.
Octane numbers are measured using single cylinder engines that look more like something out of a Model T than any modern engine. These so-called “knock” engines are operated by trained technicians in labs under controlled conditions. Two tests are used – one for Research Octane Number (RON) and another for Motor Octane Number (MON). The RON test results in a higher octane value than the MON test.
If you average RON and MON, you get an octane value called AKI, short for Anti-Knock Index. It's often labeled (R+M)/2, reflecting the fact that it is the average, or midpoint, between RON and MON. AKI is used to rate retail pump fuels, and it is the most commonly used octane value for race fuels as well.
For example - Sunoco Ultra 93 typically has a RON of 98 and a MON of 88, thus yielding an AKI of (98+88)/2 = 93. If you look closely at the yellow octane labels at gas stations, you'll see the (R+M)/2 description under the big octane numbers. We provide all the octane numbers for all our race fuels - RON, MON, and AKI. So while we may refer to fuels like SR18 as "118 octane" (that's the AKI value), we also show the RON and MON numbers under "Technical Details". For SR18, that would be 120 and 116 for RON and MON, respectively.
Many times you’ll hear that MON is more important than RON because the MON test is performed under higher temperature and engine speed conditions. While this may be true, the laboratory test conditions are not indicative of what real race engines – heck, even mild street/strip motors for that matter – see at the track. Also, some engines have shown a better correlation between horsepower and RON. So, a word to the wise: don’t get hung up on octane numbers.
For a great example of why octane is not the only fuel parameter to ponder, consider the engines used in Formula 1. These engines have compression ratios exceeding 18:1 and spin at RPMs pushing 20,000. Sounds like a candidate for 116 octane race gas, right? Nope - they use a 96 octane fuel!
It’s hard to find a wider variety of race cars than what shows up at your local drag strip. On any given weekend you can see all sizes and shapes of engines ranging from raspy 4-cylinder motors to booming big blocks, and with all kinds of power adders thrown in the mix. This is where looking beyond octane becomes real important. What works for your buddy’s Pro Stock car may not be the best choice for your other buddy’s turbocharged import.
Naturally aspirated race motors with large combustion chambers spinning at high RPMs really like high-octane, fast burning fuels. They need the octane to prevent uncontrolled combustion, and they need a fast-burning fuel so that the flame front can span the large bore of the combustion chamber quickly. If you’re not sure which fuel burns faster than others, one indicator is specific gravity. “Lighter” fuels – fuels with a lower specific gravity – tend to burn faster because fast burning hydrocarbons are themselves light. Look for a specific gravity close to 0.70 and you’ll likely find a fast burning fuel. Of course, consult with the fuel producer to verify your assumptions. You might be surprised to learn that some of the highest octane fuels may also be some of the fastest burning fuels!
You might also be surprised to know that fast burning fuels may not need as much timing as their slower burning counterparts. Many times we get calls from individuals who are dialing in new motors on a fast burning fuel but they’re using timing and jetting numbers from their old motor and fuel combo. “Retard the timing a couple degrees and see what happens” is not the suggestion they expect to hear! With high octane, fast burning fuels, it is easy to dial in too much timing. In such cases, the engine is not detonating, but it is past the point of optimum spark advance, so it’s just heating things up and making less power. A little less timing may really wake up the motor.
http://www.racegas.com/article/10
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