Fuel Rumor

:devil I HAVE HEARD THAT YOU CAN RUN "VP FUEL " IN THE 400EX IS THIS RUMOR TRUE.IF NOT WHAT IS A SAFE OCTANE RATING.

We use 76 VP race fuel in our Quads. It's 110 octane. We actualy run 50/50 mix (110/92) octane for cost efficency when playridding. Then when we race we use 110 only. Our motors have had work done and are 11.1 comp ratio. If you are running a stock Quad then 92 will be fine. Unless you wan to spend 4.00 a gallon on race fuel.

Hope this helps.

I just love the smell !!!:D

Race fuel will do nothing for a stock motor,,so don't waste your money,,just run the highest octane they sell at the local gas station.

[JabberJaw]

2001 400ex W/bearded fenders, plastic flywheel, paper airbox. Extended Fisher Price Racing A-arms, Red Rubber Brake Lines. Tonka case saver, Rubberband steering dampner, perch for the parrot & lever 2000, Used E-brake blockoff, Rubbermaid axlenut. Auqu header, Mopar powercore, Wooden handle bars. Paperclip racing handlebar clamp, pantyhose headlight covers, & paper number plates. AC/DC racing front bumper, fiberglass swingarm skid, full body wine dispencer, & propeller nerfs. Sponge for air filter, black neoprene hood cover. Ceramic eliminator axle. Dimsum triple rate shocks W/rezzy, Tupperware black gas tank cover, stripped wire kill switch & ammco power shifter, Sandpaper seat cover, Styrofoam resevior cover, Gas petrock, Rear master bater guard, seat launch & head cover, Chrome tires and rear brake pedestal, Custom oil retainer scoops, Tyson hand guards, Dynomite kit, XR50 cam, JE 16 piston(1.8:1), Douglas Fir .19 race rims W/knockoffs, hole**** BMX tires all around

[JOEX]

If you ain't broke,,then you ain't high enough. :eek:

You guys got too much time on your hands...nice mod list jabber..:D LMAO

[JabberJaw]

It's a nice bike! Hehhehehe

[papaw]

hey zooter,have you tried anything lower than 50/50 on your 11:1 piston?i ran 110 all last summer,and have since found out that any modded motor or stock motor for that matter needs the lowest octane possible (without detonating or pinging)to get the best power out of a motor.somebody correct me if i'm wrong.just trying to get some ideas on what the lowest octane rating for an 11:1 piston.

Well it's true you should run the lowest octane fuel without pinging. The only thing about this statemnet is, it was intended for cars and trucks. In a car or truck you are consuming a lot of fuel over a peroid of time. So for cost effectivenest you should run lowest octane for cost effictivenes. Your car/truck is also liqiud cooled too. So running race fuel to lower combustion temps is not a factor. On a atv that is air or even liquid cooled it is more importaint to run better fuels for cooling effiency. Plus your not buring 1000 gals of fuel a year in your quad (some of us do) so the cost factor doesent play a part. Grannted you will have better fuel econemy using a low octane fuel that burns 100% (no internal combustion engine is 100% efficent) of what you put in. On race fuel you may only burn 90% and the other 10% helps cool things down a little.
It's all super confusing, If you have an modified ATV/ATC/whatever with a higher comp piston you should always check with the manufactor and see what they say. Everbody has a different opion on this topic. I run 50/50 playing because of the higher comp and it helps slighly to cool things down. When I race I use 100% VP 110. I cant realy tell a differance in running but who want to take a chance? Only 4.00$ a gallon and You only need 2 to race.

That's ny two cents worth.

[thorspapa]

Rule of thumb for octane on different compression setups.

Air-cooled engines 125cc - 450cc - up to 10.5:1, premium pump fuel. 10.75:1 to 11.75:1, mix race and pump 1/2 and 1/2. 13:1 and higher, race fuel or alcohol.

Water-cooled 125cc - 450cc - up to 11.5:1 (12:1 on some engines), pump fuel. Anything higher, race gas.

Smaller engines can deal with higher compression without detonation (less surface area). Really big bore engines (like an XR600) won't deal with compression well at all, and will require higher octane fuel than the compression ratio would seem to necessitate.

For the 250Rs, if you're looking at over 180psi readings, you'd be better to use 95 or more octane, chances are you have detonation and don't know it.

I'm not going to say this is straight out of "The Book of Truth", but it's worked well for myself and many others. It's also a guideline given by Powroll.

Disclaimer: If this doesn't work for 'ya, don't sue me, I have no money anyway
:D

[out4sand]

.
We use 76 VP race fuel in our Quads

When I race I use 100% VP 110. I cant realy tell a differance in running but who want to take a chance? Only 4.00$ a gallon

zooterboy

Are you running 76 race gas or VP? If you are running VP do you know which grade? such as c-12? If your running c-12 and can get it at $4 a gallon that's cheep, at least for around here! Most shops are changing to 76 race gas because it's a little better price per gallon but I like the way VP runs better and it smells better as well

[Leo]

camshaft profile has a signifigant impact on what octane you need to run...

(more overlap has the effect of dilluting the mixture somewhat with exhaust gasses, effectively cooling the combustion chamber, allowing higher compression with lower octane... Basically a lot of camshaft overlap has the same effect as an automobiles EGR valve.. lowering combustion temps, which reduces NOX emmissions and 'pinging')

Yikes.. that sounded a bit technical :)

To the best of my knowledge, the only time higher octane fuel has a cooling effect is if the motor is running hot because of pre-detonation (just because you can't hear it doesn't mean it's not happening!)..

Personally to be on the safe side anything over 10.5 to 1 I'd be running at least a 50/50 mix..

But like most folks I think I'm addicted to the smell :D

Leo

Sorry about that, We use 76 race fuel (110) in the winter. I couldn't tell you what they call it. We have to drive to the indinapolis 500 race track to get it because everywhere here localy don't carry it from NOV-March. In the spring we buy VP113 I think. I've been getting it for so long I don't pay attention to what it is, I'm just programed to go and say FILLER UP, Then they take my 40.00 for 10 gal. What a bargin.

Although it is pretty cool to go to the indy track and get to see the garage area.

[DEAL]

AC/DC from bumper lol that was good.

[Holty]

Leo,

how bout throwin' this post in the FAQ section?

Good info in here.

[Revin300EX]

According to the people I have talked to, It is always important to run the lowest octane rated fuel possible, without pinging.

Remember, Higher octane means less energy (This is why Diesels are very low octane). So you want the most energy possible to come from your motor, right?

True, you may be pinging and not know it. But if you cant hear it, its not causing a problem big enough to worry about. Plus, running an octane rated fuel that is too high for your motor is even worse than running one that is too low. A broken connecting rod is far worse than a little bit of detonation.

I personally like to run VP race in my quad. I run it fuel strength with Klotz upper cylinder lubricant mixed in it. Supposedly the klotz will slow down the wearing process in the upper cylinder and it smells real good. The only significant difference I can tell is a crisper sounding engine and possibly quicker revs. I'm sold on runing race gas because of running it in race cars. I never have had a det. problem or heating problem. The only drawback is the price, it is 4.25 dollars a gallon and a pint of Klotz is 10.50.

[Holty]

do you have a stock quad? what is klotz? more info please.