Can I mix U4 with 93 for one ride?

[Nick110]

Help guys the shop where i get my U4 from ran out of it today and I have about a quarter tank left. Can I mix 93 with U4 and run that for practice today?

[Nick110]

Or can I drain all the U4 out and just run 93? I have a 13.5.1 wiseco with a 02crf cam.

Help me guys

[400exrider707]

I wouldn't try 93 on that compression, even with the cam, just not worth the risk to me personally. I suppose you could mix them, I'm not too sure how good it is actually because U4 is a pretty specifically blended fuel.... also switching back and forth between U4 and anything else isn't a good idea because you should have rejetted to run U4, so going back to a non-oxygenated fuel would throw jetting off. Just my 2 cents.

[quadracer707]

We run u4 1gallon to 4gallons of 93, for our yfz 450 13:1 piston, that is the way our engine builer recommended, our you running staright U4??

Ken

P.S. I defferently would not run JUST 93 in that set up

[400exrider707]

Originally posted by quadracer707
We run u4 1gallon to 4gallons of 93, for our yfz 450 13:1 piston, that is the way our engine builer recommended, our you running staright U4??

Ken

P.S. I defferently would not run JUST 93 in that set up

How do you jet for that, are you sure those fuels even blend together correctly? I wonder what VP would say about this. Where is GPracer2500!

[TRX450RACER174]

I run U4 w/91oct 1gal U4 to 4gal 91oct but i live in Cali so my fuel is already oxygenated from the pump.

[quadracer707]

Why wouldn't you be able to run like that mixed, we ran mixed ratio with 440ex & now with yfz450, according to engine builder running straight u4 is a waste of money for our setup, Quad runs loke a raped ape & now getting carb bored out to run FASTER

[400exrider707]

Originally posted by quadracer707
Why wouldn't you be able to run like that mixed, we ran mixed ratio with 440ex & now with yfz450, according to engine builder running straight u4 is a waste of money for our setup, Quad runs loke a raped ape & now getting carb bored out to run FASTER

Well I always find it odd that people mix fuels like exotics such as U4, especially after a company like VP put so much research and time into creating it. I'm not saying you're wrong for doing it, I really dont understand it well enough to say that. Why would U4 be a waste? Its oxygenated, much more so than anything at the pump, and has been dyno proven to add up to 2 hp when jetted for correctly.


How many of you guys are draining your carbs after every use of U4 out of curiosity?

[Nick110]

Originally posted by 400exrider707
Well I always find it odd that people mix fuels like exotics such as U4, especially after a company like VP put so much research and time into creating it. I'm not saying you're wrong for doing it, I really dont understand it well enough to say that. Why would U4 be a waste? Its oxygenated, much more so than anything at the pump, and has been dyno proven to add up to 2 hp when jetted for correctly.


How many of you guys are draining your carbs after every use of U4 out of curiosity?

I dont do it everytime but if im not going to be riding for more than 3 days I will drain it. My team mechanic said that is alright to do.

[400exrider707]

Originally posted by Nick110
I dont do it everytime but if im not going to be riding for more than 3 days I will drain it. My team mechanic said that is alright to do.

Not saying your mechanic is wrong, not sure of his background or knowledge, but it does say right on the VP gas can to drain carb after every use. It eats the rubber seals.

[TRX450RACER174]

I only mix mine cause we do not have 93oct on the pump in Cali
we only have 91 so i mix mine to gain a couple of points in octane.
And no i do not drain my carb after every ride or race.

[400exrider707]

For those of you mixing to solely gain octane, why use U4 and not a less expensive fuel in the 100 octane range? U4 is around $15 a gallon, seems like a waste to use it at all if you're doing it to only gain octane points.

[TRX450RACER174]

I use it cause it is oxygenated, our fuel in Cali is also oxygenated so i am not mixing oxygenated and non oxygenated fuel.

[400exrider707]

Originally posted by TRX450RACER174
I use it cause it is oxygenated, our fuel in Cali is also oxygenated so i am not mixing oxygenated and non oxygenated fuel.

Again I'm not saying its a bad thing to do, because frankly I dont know if it is or isn't, but why not mix it with C12 or something of the sort that is only say $6-$8 a gallon as opposed to U4 which is $15 a gallon.... you're only mixing to save money anyways, why bother wasting MORE back on the U4?

[Chino886]

Originally posted by TRX450RACER174
I only mix mine cause we do not have 93oct on the pump in Cali
we only have 91 so i mix mine to gain a couple of points in octane.
And no i do not drain my carb after every ride or race.

If your mods are correct in your sig, you might as well just run straight pump gas with no U4! if you are running stock 06 piston (12.25:1) you would be better off sticking $20 in a can everytime you buy quad gas and you will have a nice savings to buy something for your quad.

Just my 2 yen!

[TRX450RACER174]

I get what you are saying but c12 is 108oct non oxygenated, the u4.2 is 102 and is oxygenated all i am doing is adding a few extra points to my oct rating without diluteing the oxygen level. I have mixed with c12 before w/no probs but when money isn't a prob a try to buy the u4.

[Chino886]

Originally posted by TRX450RACER174
I get what you are saying but c12 is 108oct non oxygenated, the u4.2 is 102 and is oxygenated all i am doing is adding a few extra points to my oct rating without diluteing the oxygen level. I have mixed with c12 before w/no probs but when money isn't a prob a try to buy the u4.

Either way you will get the same effect, money coming out your exhaust along with decibels of exhaust! Just trying to save you some hard earned cash! ;)

[TRX450RACER174]

Originally posted by Chino886
If your mods are correct in your sig, you might as well just run straight pump gas with no U4! if you are running stock 06 piston (12.25:1) you would be better off sticking $20 in a can everytime you buy quad gas and you will have a nice savings to buy something for your quad.

Just my 2 yen!

True my sig is correct but my races are 45 to 60min long and i just like to have the little extra oct in the gas to be safe, maybe call me paranoid i don't know if the few extra points make the difference but it is piece of mind for me.

[TRX450RACER174]

Originally posted by Chino886
Either way you will get the same effect, money coming out your exhaust along with decibels of exhaust! Just trying to save you some hard earned cash! ;)

Alright my next race i will run straight pump gas and see how it goes if there is a difference or not , who knows i might not notice a difference. Thanks Chino:D

[Chino886]

Originally posted by TRX450RACER174
Alright my next race i will run straight pump gas and see how it goes if there is a difference or not , who knows i might not notice a difference. Thanks Chino:D

Try it out and let us know!

Then i'll send you my bill for $20 :blah:

[K_Fulk]

Originally posted by 400exrider707
For those of you mixing to solely gain octane, why use U4 and not a less expensive fuel in the 100 octane range? U4 is around $15 a gallon, seems like a waste to use it at all if you're doing it to only gain octane points.

U4 motor octane is only 92 (96 or so in the regular formula of octane rating.) . so using it to gain octane points would be a waste.

Do I mix it, yes. On my yfz I just want a little bit of lead in the fuel. So I mix it 4:1 with 94.

Would I normally buy u4 just to mix with reg gas, no. But I got it dirt cheap.

I don't bother draining it, I figure after being diluted down to 20% I won't hurt the selas all that much.

[Nick110]

Originally posted by K_Fulk
U4 motor octane is only 92 (96 or so in the regular formula of octane rating.) . so using it to gain octane points would be a waste.

Do I mix it, yes. On my yfz I just want a little bit of lead in the fuel. So I mix it 4:1 with 94.

Would I normally buy u4 just to mix with reg gas, no. But I got it dirt cheap.

I don't bother draining it, I figure after being diluted down to 20% I won't hurt the selas all that much.


Word

I get it for free so why not run it, but the team happened to run out of it the other day before the new drum came in so I had to run it with 93.

[TRX450RACER174]

Originally posted by K_Fulk
U4 motor octane is only 92 (96 or so in the regular formula of octane rating.) . so using it to gain octane points would be a waste.

correct U4 is 92. U4.2 is 102 octane thats what i use.