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yz_ripper

VP Race Fuel

12 posts in this topic

Hey guys, im sure some of you use VP in your bikes. I used to use it all the time in my 2-stroke (loved it!). Since then i've always run pump fuel in the 450 but i got a local shop that sells all the VP fuels. Money isnt an option, so what type of fuel would you run in a 08 yz450 and would you consider cutting it 50/50 with 93 octane? Looking for type IE. (v12, c16, etc.) and your opinions after adding the fuel, both good and bad.

Thanks guys

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I use the U4.4 for race day and love it. I can notice the increased power with it. No special head modifications on mine other than a High compression piston so the only gains I will notice come from Oxygenated fuels..

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Read:

The trouble with mixing pump gas and race gas is that it's a lot like mixing chocolate ice cream with dog :thumbsup:... The result tends to be a lot more like dog :bonk: than chocolate ice cream.

Best analogy ever!!

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Read:

http://www.vpracingfuels.com/motocross-racing-fuel.html

The trouble with mixing pump gas and race gas is that it's a lot like mixing chocolate ice cream with dog :thumbsup:... The result tends to be a lot more like dog :bonk: than chocolate ice cream.

Clearly an admission that (most) pump gas is dog ****. Agreed.:ride:

If the consequences of not running pure race fuel could lose you some major race event then mixing it with pump gas would obviously be a bad idea. If on the other hand you're just looking for a little more power, then mixing race gas with pump fuel is pretty effective.

Lately I've taken to mixing as little as 5% straight toluene with my fuel. It's not going to make me or my bike and "faster" but you can definitely feel the crisper power delivery and better low end pull out of corners (for example).

In my experience you don't need to get anywhere near 50/50 to feel the difference. Depending on the fuel, your bikes characteristics, and environmental conditions somewhere between 5%-20% race fuel to pump gas seems to work well without adversely affecting the jetting/mixture situation.

Oxygenated fuels are another story...

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Clearly an admission that (most) pump gas is dog ****. Agreed.:thumbsup:
Depends on where you are in the nation and the world, really. Surprising and counter intuitive though it is, the pump gas in San Diego County is actually not bad at all.
Lately I've taken to mixing as little as 5% straight toluene with my fuel. It's not going to make me or my bike and "faster" but you can definitely feel the crisper power delivery and better low end pull out of corners (for example).
This is a much better and less expensive solution to improving pump fuel, IMO (as opposed to simply replacing it). I know people who use 20% toluene, but they do rejet at that level. 5-10% is certainly safe. Toluene is already a component of a good many gasolines (what, you thought it was one single chemical?), and you can find it at most paint or hardware stores.
Oxygenated fuels are another story...
Please explain. VP u4.4 is oxygenated.
Oxygenated fuels release oxygen into the combustion process, and generally require richer jetting to compensate for that.

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Oxygenated fuels release oxygen into the combustion process, and generally require richer jetting to compensate for that.

I know that, but it sounded like he was saying oxygenated fuels are bad. Maybe i misinterperated that :thumbsup:

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:thinking:Is this toluene used simply to boost octane or are there other benefits aswell?

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Toluene bumps the octane number up to varying degrees on most pump fuels. How much depends on the specific formulation of the you add it to, so it's hard to say that X% toluene will raise the octane number Y points.

The main benefit is the increase in energy content it will usually provide. Again, the effect varies, but most pump gas gets a pretty big hit from it.

Here's the contents of the original U4 as an example:

Benzene

Toluene

Dimethylbenzene (xylene)

Ethylbenzene

Styrene (ethenyl benzene)

1,3-Butadiene

Isoprene

N-Hexane

Pentane/pentadiene

Cyclopentadiene

Lead

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