race fuel

[pitcrew]

hey im going to be using vp u 4.2...does anyone use this and do they drain it out of the throttle body cause i know this stuff does wonders on carbs.

[atveric132]

ive never used it but ive never heard good things about it

[shiftyfofiddy]

here ya go

http://www.motocrossactionmag.com/me2/dirmod.asp?sid=&nm=&type=news&mod=News&mid=9A02E3B96F2A415ABC72CB5F516B4C10&tier=3&nid=8D2CC325E9E24D60B4527665EA6C2D1C

[shiftyfofiddy]

so im guessing your going to have to re-map your ecu because it does burn faster witch may cause it to run lean. i had to re jet my bike with it so just keep an eye you

[atveric132]

never said it was bad fuel just said ive never heard anything good about it. i run MR9 in my race bike

[shiftyfofiddy]

well when i used it i noticed a lil difference after i got jetting better.

[panici33]

I use it and you will notice a difference; I have been told it makes more hp than the MR9 too.

You do not have to drain it. The old U4 you did but the U4.2 does not gum up. If you ever have any questions about VP just give them a call; they have really good tech service.

I will continue to run U4.2 but may go back to Klotz once I am back in the Midwest, good race fuel too and a little cheaper than VP.

[jerkyboy]

We used to run mxr01 and liked it. But if your going to let thr quad sit for a week or more we turn the fuel off and run it till it died.

[kfx400rider03]

does it gum up or something?
and how long can race fuel set in the cantainer or gas tank of a quad?
does i go bad or anything?

[panici33]

Race fuel will go bad just like any other fuel. VP doesn't recommend keeping the fuel in your tank longer than a month without running the bike. It's different for each type of fuel of course. Like I said before, the best thing to do is to talk to the people that make it.

You have to remember that your tank is plastic and the container you keep it in is plastic and the fuel will eventually make its way through.

Someone should do a little science experiment.:blah:

[miles Machine]

most fuels actual START deteriorating after about 2-3 weeks

[kfx400rider03]

[QUOTE]Originally posted by panici33
Race fuel will go bad just like any other fuel. VP doesn't recommend keeping the fuel in your tank longer than a month without running the bike. It's different for each type of fuel of course. Like I said before, the best thing to do is to talk to the people that make it.

You have to remember that your tank is plastic and the container you keep it in is plastic and the fuel will eventually make its way through.

Someone should do a little science experiment.:blah: [/QUOTE

il do the esperminent if you supply the fuel and and the gas tank thats gonna get messed up:blah:

and yeah i figured it would be a couple weeks to a month

[Drewltr450]

i wish that all gas stations sold race fuel it burns so much cleaner then pump gas. and no 10%ethanol. When i ran race gas for a few tanks my valves and piston actually were about 85% cleaned off of any carbon buildup. i actully said wow when i saw it. cam2

[kfx400rider03]

when you run ras gas how big of a remap is it? can i just just do +or- 1 on the map program? or is there more to if?

a gas station buy me sells power mist race fuel for about $60 for 5 gallons:mad: :rolleyes:

[miles Machine]

if your just running higher octane without having emgine mods that increase performance (heat) then your not going to see much if any difference at all...and if you insist on running it you would need to adjust for ign timing not your fuel to make more power...now if you running an oxygenate then you will need to raise your "jetting" and you can get that close with the programmer buttons so that it runs right but you wont get top performance out of it unless you use a dyno or have an analyzer for the exhaust to get the fuel ratio

[kfx400rider03]

yeah i know but im looking into high comp pistons and a intake cam. an just trying to learn somethings before i go out there and purchase these parts and then end up kicking my self in the arse for making a mistake.

and i know 12.5:1 piston compresion is the max i guess you could say for pump gas but i cant find a 12.5:1 pistone from je beside atp's and they want $100 more for the piston when i can get a je12.8:1 piston for 150 ish. so my question is " is that .3 compresion ratio realy gonna have to make me run race gas"? i dont realy care if it does just woundering

[miles Machine]

most likely not..but you could always mix 110 and pump 93 and that would deff be enough octane for thos mods and maybe a few more

[kfx400rider03]

thats what i figured i could do. like 3/4 or a ggallon of race and the rest pump (rest meany the other 1.4 gallons) and was gonna probaly get a cam too

[miles Machine]

yeaa youd prolly be good with a 2 to 1 ratio

[kfx400rider03]

a 2 to 1 ratio of 2 gallons of pump "92" to 1 gallon of 110 = 3 gallons of 98 octane.
2 gallons of 92 oct. so 2 x92=184
1 gallon of 110 110x1=110
sence there is 3 gallons divide by 3 and get 98. sound right? i think

[miles Machine]

yup

[kfx400rider03]

sweet thanks for the hel wasnt to sure if it was ok to mix the gases

[KingpinsEx]

I read an article in quad a while back when they tested the factory Yamaha quad and said they only run VP U 4.2 for a fuel injected bike. Anyone have prices for how much it runs? I'm planning on adding a 13.5:1 CP piston, curious if I will have to run it straight or can I mix with pump 93.

[panici33]

Depends on where you're at or who you get it from but here in AZ I can get 5gal. for $65. I have known guys that have mixed it with pump gas, but that kind of defeats the purpose of having race fuel and a hi-comp piston; they only did it to save a couple of bucks, not sure what compression they were running though. I say if you can't afford the race gas run stock compression.

[kfx400rider03]

i went to my local quad shop and they said they could get it for me. and check at some gas stations or ask around at auto parts stores too

[KingpinsEx]

Yea I have a local gas station that can get VP Fuel just haven't checked with them on a price the the U 4.2 yet. Just wanted to get a baseline price to expect...13 bucks a gallon ouch!:eek2:

[kfx400rider03]

a gas station near me sell power mist with octane rating 112 for $55 for 5 gallons

[KingpinsEx]

Originally posted by panici33
I say if you can't afford the race gas run stock compression.

I can afford it, but at 13/gal it will def. take its toll through an entire season of mx. I'm just curious if its worth it, or would I be better off going with some head modifications. I'm getting a cam and PC5 to go along with it. The reason I want to go high compression is I need a new piston and seems like I might as well get high compression than stock or barley over. So I have to buy a piston, the only extra cost will be the fuel, but I def. want more power... You guys who run it, is it worth it?