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David_Gronlund

VP 4 stroke fuel

13 posts in this topic

I was at the Phoenix SX last saturday and they were talking about a new VP race fuel designed especially for 4 stroke motorcycles. Any body know what the difference is? I was thinking that it probably isn't that much different than the other VP fuels, and they are just trying to strum up more business sense everyone seems to be switching to thumpers.

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I don't know if it is higher octane rating, but it cost around $20.00 a gallon.

David, are racing at Lake Pleasant?

Ben

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VP has a website that gives info on their fuels:

http://www.vpracingfuels.com

I've been looking at it recently and I did not see anything named specifically as "4 Stroke Fuel", but they do list C14 as a fuel for "4 stroke motorcycle racing".

I've got my bike into Piper Performance for valve work and Cliff recommended MS103. He says it is basically what they recommend to replace pump gas in the newer high compression 4-strokes. $4.89 a gallon. All my valves were pitted and he suggested to either introduce some lead into the fuel for better cushioning or to run the MS103 since it will burn much cleaner. Brenda (BikeDestroyer) has been running the MS103 for a little while but she says she went to a 50/50 blend with pump premium for better starting.

I'm going to see if I can get my bike jetted for the MS103 once I get it back. Not necessarily looking for more HP, just want to avoid the cost of valve replacements! :)

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I dont know if you are talking about VP Ultimate 4, a four stroke fuel or if there is something newer out there. However Ultimate 4 was reviewed in several mags last year. Which is where I heard about it. I have run 20 gallons thru my WR and there is a very noticeable boost in throttle response and power across the board. The difference in power is well worth the price. Try it, you will love it. I am paying $11 per gallon, and getting it thru a dealer in 5 gallon cans ($55). I believe the octane is 96, remember higher octane doestn mean more power.

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Would you need to jet properly for high-octane fuel? If so, which way? Since high-octane means slower burn rate, wouldn't that essentially create a leaner condition?

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I'm not sure I follow the financial savings in spending $5/gallon on fuel. Eventually, you'll have to replace your valves anyway. Is it REALLY that much savings? For every 100 miles, you're spending another $10-12 on gas. How long before your valves need replacing? 2000 miles and you've got almost $250. I haven't checked into the price of valves, but my bet is they'll last longer than 2000 miles, even with pump fuel, and the money you save on fuel can be used to buy new valves (if needed). :)

Yes, I have three children...my money is spent before I get it. :D

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I have been buying some vp 4-stroke gas and its 8bucks a gallon at the track. I was told it had a little bit of lead to help lub, but could pass tech inspection at superbike races. The stuff smells awesome, almost like rubbing achoaal and its blue. Makes my bike run cooler.

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There are many benefits to running higher octain fuel, a couple of things right off the bat are, your engine will run cooler, your engine will generate more horsepower. A problem you may run across using pump gas is that i believe you really do not know the true octain level of the fuel your buying. it's like pot luck or something.

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dezrcr,

I plan to be at Lake Pleasant race, I've already registered. It is one of my favorite races, but it will be hard to race without a bike. Yamaha really has me by the balls right now. If I do get the bike in time, it'll probably be close to bone stock for the race.

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Higher octane will make the engine run cooler but if you don't need the higher octane due to increased compression you are wasting your money and the engine will actually lose power due to it running "flat". There is more explosive power in 80 oct than 100. But higher octane creates a slower more controlled burn rate. Thus preventing detonation. If you must run 1 or 2 gal of race gas and blend with mogas in a 5 gal can.

Cher'o,

Dwight

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Well as I said, Butta, my bike's in the shop right now and the cost is to the tune of roughly $400 parts and $400 dollars labor to replace all the valves and do a complete valve job. Not to mention probably a month of down time before it is all said and done. I've got on the order of 3000 miles on the bike and it's hard to tell how many of those miles were running on degraded compression due to the pitting of the valves. Also, I've been battling the "zero lash" problem with the middle intake which has "tuliped" or "sucked into the head" as my mechanic put it. I'm hoping a cooler, cleaner burn with less hot spots from carbon build up will help mitigate that problem as well since it seems that it may be heat related.

In the long run I might not really be saving very much money, but there is also something to be said for keeping the motor in the best shape possible (I also don't use the cheapest motor oil I can find, either). And as Dwight suggests, a blend with pump gas might be the better alternative for performance and would not increase fuels costs all that much. :)

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Higher octane doesnt mean more horsepower. As others mentioned octane ratings are related to ignition with compression and heat. High compression engines can cause low octane fuel to detonate/knock/pre ignite before the spark plug lights up. This is bad.

VP ultimate 4 is 96 octane, but the extra power increase comes from the fuel being oxygenated. It has oxygen in the fuel, yes this will lean out your jetting, and provide a very noticeable increase in hp. I did not have to change my jetting. I can slam on the gas with out the engine hesitating, like pump gas does, which can also be fixed with the BK mod. I have no idea about lead in the fuel, cushioning valves and what not. I dont think saving $ has anything to do with it. Its about making my WR more competitve while racing. I think running leaner will make the engine run hotter, and could shorten valve life. I only run it for races, and then go back to pump gas, which is fine for regular rides.

MXA did a nice article on fuels last year and may be on the web site, although I am not positive.

Funny how (mostly car stuff) octane boosters are advertised as increasing hp, throwing out words like Turbo and stuff. I supose the only way octane booster would increase HP would be if you car/bike was running so crappy with knock that it barely ran.

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I've got a 06 ktm 450 exc with stock jet settings. I usually just run 91 octane premium fuel, but I thought I'd try C14 since it was available at a local shop. I tried ratios of 1:10, 1:5, 1:3, and 1:1 of C14:91 octane pump gas without adjusting the jetting at all. I noticed a very noticeable increase in throttle response with all the different ratios especially with 1:1 mix. I could lift the front end up in first, second and third gears if the traction was right. I live in the SE corner of British Columbia in the rockies so I am at a fairly high altitude. My guess is that the stock jet settings were way to lean and this fuel is finally getting the mixture as rich as it should be. I'm installing a high compression piston, FMF 4.1 system pipe and exhaust and a JD jet kit, since this fuel is hard on the wallet... It was fun though. :lame:

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