Switch from Pump to C-12
- Thread starter Txbigguy
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That's becuase VP Red is is a poor choice for most motorcycle applications. Of course that doesn't stop people from using it and complaining that race gas doesn't do anything. ;)
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Dr. Dave Redszus the blender of FirePower race fuels gave me these numbers as typical values at the refinery for Northern Illinois in the summer.
10% - 158.0
50% - 250.0
90% - 374.0
End point - 437.0
The EPA can provide the seasonal temp ranges for your area, but there are a couple of key points to remember. The EPA seasonal values only have to be met at the refinery not the pump. The 50% distillation temperature in Illinois (summer) has an acceptable range of 170-250F . Think about that. A single point on the curve can vary by a larger range than most race fuels change from 10-90%, and that is at the refinery point. By the time it gets to your engine the range is even greater. I have a fuel quality study done by American Automobile Manufacturers Association from a few years back. They did tests at the pump at a wide range of locations. I'll try to dig it up , but the basic point was what comes out of the pump is vastly different from the "numbers" the EPA quotes. The relative quality of pump fuel is really bad.
Considering all of that it's no surprise that pump fuel is a poor choice if performance and good response is your objective.
wow, that's a high end point! I would think if I tried running fuel like that in the winter time, even more of it would just shoot out the pipe as spooge, and the bike would run even leaner than expected (especially on a liquid cooled bike with no thermostat). If this theory is correct, many snowmobiles could be jetted much leaner if run on proper fuel, but then again that would get a bit expensive feeding three big Mikunis instead of one.
I wonder if 20 or 30 years ago pump fuel varied this much? Or are these folks taking advantage of the fact that most modern vehicles have oxygen sensors and automatically adjust (within limits) for differences in fuels?
I wonder if 20 or 30 years ago pump fuel varied this much? Or are these folks taking advantage of the fact that most modern vehicles have oxygen sensors and automatically adjust (within limits) for differences in fuels?
That tends to be true for ANY engine all year long. The higher an engine revs the more significant the influence of proper distillation curve will be. It takes time for fuel to vaporize and there is less of it available as the rev limits of new engines increase. Nothing of late is funnier to me then a guy who can jet his way out of an empty field who drops $400-$800 on an exhaust system, ignition and intake plate hoob-a-joo for his 250F then pours pump gas in it and proceeds to bounce it off the rev limiter. No wonder these guys wear out main bearings and rods so fast, half their fuel is still liquid in the combustion chamber and running down into the crankcase dilluting the oil. :silly: All the idiotic my oil is better than yours posturing is pretty moot when 5% of your crankcase is filled with raw fuel. :silly:
The months of spring where pump fuel is being transitioned from a winter blend to a summer blend can make jetting really erratic because the blend from the same company can change pretty dramatically between fill ups. When guys argue that their bikes are jetted SPOT ON with pump fuel and still bitch about endless "performance" maladies I stop listening. There is only so much ignorance driven smoke that can be blown up my butt before it gets hard to sit down.
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OUCH :moon:
Just seen it happen this weeked to juniors friend...bike was set up perfectly on fresh C12. The dad decided to run AV gas because he gets it cheap. He said he was told it is just as good if not better. Well a dnf at a national race when you are leading the series stinks..... Talk about a sore butt.
Early in this thread someone mentioned VP Ultimate 4. A friend put it in his DRZ and said it worked fine .. no jetting changes at this point. We tried it in Juniors RM85 (100eg.kit) Junior keeps it pinned alot. We noticed some detonation at hi RPM. I did run it with 1 & 2 size over main jets. MR2 seems better. I sometimes add 5-10% VP red to these fuels to raise the End Point to cool things down.
I want to run race fuel in my CRF. I Just bought 5 gallons of sunoco 110 . OOPS! I didn't really notice any difference. Is the VP ultimate 4 what I want to use? Any ideas on price? We're up here in Gods country at about 4800ft. Jetting gets to be game around here. One day 65 degrees and 90% humidity and the next it's 85 degrees and 10% humidity! :think: The last thing we need is irregular consistency in our gas.
Rich, have you wrote a book yet? :) on everything! :worship:
Rich, have you wrote a book yet? :) on everything! :worship:
IMO, it's not a particularly good choice for CRFs or YZFs either. They have very short intake tracts, run much higher rpm than say a CR250, and transition through the rpm range much too quickly for a fuel like this.
It would be an OK choice in a low rpm, slow revving engine like an XR600.
I haven't run Ultimate 4 so I can't comment other than to remind everyone that VP is a marketing company, so it might be best not to have blind faith in all of their advertsing claims. ;)
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I understand that any company that has somehting to sell will tell you what you want to hear just so you buy it. I just don't have the knowledge yet of what to look for on race gas. I've had to read this thread twice. MY BRAIN HURTS!!! If anyone has had good luck with any fuel on a CRF, please comment. Rich, strait up, what would you run in a CRF?
:worship: :worship:
:worship: :worship:
I generally run Phillips B35 (now called TT101) in warm weather and run Phillips B32 when it's cooler out. I jet for the B35 so as it gets colder the change in air density will pretty much balance with the richer running of B32.
Dr. Dave Redszus who did a lot of fuel blending work for Phillips is getting ready to announce his own custom fuel blends under the FirePower brand name, and I'll be switching over to FirePower as soon as Dr. Dave has it all up and running. Before the end month I'll have a complete write up on the FirePower fuels and the unique numbering/naming system they will be using that will pinpoint the fuel's specific characteristics. It will correspond very nicely with the things we have been discussing here.
Stay Tuned.
Dr. Dave Redszus who did a lot of fuel blending work for Phillips is getting ready to announce his own custom fuel blends under the FirePower brand name, and I'll be switching over to FirePower as soon as Dr. Dave has it all up and running. Before the end month I'll have a complete write up on the FirePower fuels and the unique numbering/naming system they will be using that will pinpoint the fuel's specific characteristics. It will correspond very nicely with the things we have been discussing here.
Stay Tuned.
- Thread starter
- #90
Rich,
Does Phillips have a website. I want to run this fuel but cant seem to find anyone around that carries it. I am here in Dallas. If you could point me to a website so I can contact someone and find out where to get it I would be very gratefull.
Does Phillips have a website. I want to run this fuel but cant seem to find anyone around that carries it. I am here in Dallas. If you could point me to a website so I can contact someone and find out where to get it I would be very gratefull.
Here you go TX http://www.cpchem.com/fuels/contact/distributors.asp#United
B
biglou
Rich-Is B35 any harder (or is it perceived to be harder) to jet for than B32? Just wondering why the local price is about a dollar a gallon more for the B32. My first inclination is that people don't want to take the time to fool with the oxygenated stuff, and buy more of the B32, therefore the shop charges more. Keep in mind, I hate this shop, but they are close. To date, one can of race fuel is the only thing I have ever bought from them in this lifetime.
I haven't found B35 to be any harder to jet. The main oxygenate (15% by volume) in B35 goes for about $10/liter on the street in small quantities, which I believe is a big part of the price difference. Even at the wholesale level it isn't cheap.
jmics19067
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Or the really high final point?
The 10% temp isn't really too bad, it's the other points on the curve that are significant. Because the temps are comparatively high, you need more heat or more time to vaporize the fuel. The XR600 revs slow and peaks at a fairly low rpm (time), and the air cooling ensures there will be plenty of heat available in the intake tract to vaporize the fuel. In addition the high end point temp can help cool the piston crown and help stave of knock a bit longer. This is a real issue on XRs that are run hard for long stretches. The downside? Too high a percentage of aromatic hydrocarbons with heavy ends makes for sluggish throttle response. Cutting VP Red with small percentage (20-50%) of a good low temp oxygenated fuel can give you a better throttle response while still retaining some of the positive aspects of the high temps for a better overall fuel in this type of application.
So, I am guessing that for, say a 125 (high reving, relatively low temps, and short intake) that you would be looking for a fuel with a fairly low 10% point (say 125-135) for throttle response, with slight "kick tail" on the curve nearer the end point (for the cooling effect)?
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Yep, that's pretty much the case. Engines that don't get pushed at WOT for extended periods tend NOT to need the tail at the end of the curve. B35 is a pretty good general purpose curve to use for comparison purposes.
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