Race Fuel

[MightyDuc Racing]

Oh yeah...11.8:1, but I just can't afford any more motor repairs so I don't want to risk it anymore.  I'd really like to have just one troublefree weekend before the season is over. ;)

[Super Dave]

I found some 112 octane VP for $6.05 or 116 for $7.45.  Gonna try the 116 mixed 1/2 with 93 pump gas I think at Moroso and see how it does.  Opinions?

What's that?  VP C11 or C12 would probably be the fuel's that I would think would work in this application.

As for pump gas in higher compression motors, it really depends upon the size of the bore and the combustion chamber shape.  

And as for octane, the thought that a higher octane fuel makes less power and burns slower is a "wives tale".  Fuel is chemical, and some high octane fuels that are commonly available do burn slow, but that's just their nature because they are old tech fuels.  However, a fuel that I use quite regularly (TO137) has a MON of 120+, and on some scales is as much as 147.  It kicks the living daylights out of just about anything.  This fuel does not burn slow. Really depends upon lots of things.

[james-redsv]

I was talking about pump gas, Dave. The 87 pump gas burns faster the 93, and thats no wives tail. ;D Race fuel is different as you said.

[Super Dave]

You think so?  I wouldn't agree.  I have done a lot of work in the power equipment industry.  In general, the "premium fuels"  created more heat and debris in their cobustion chambers.  You could look in the motor and tell the customer what they were using and be pretty much spot on.  Even then, they are made in huge batches, so it's really hard to say what you're really getting in pump gas.

Whether they necessarily burn slower, I don't think that's the case.  Current street gasolines are not very exciting.

[james-redsv]

Correct me if Im wrong, a Hi comp motor needs a slower burning fuel so it wont knock or ping. Right? The reason a motor knocks is the fuel is igniting too fast or soon. 87 pump gas burns faster so it will make a Hi comp motor knock. 93 pump burns slower so the the Hi comp motor doesnt knock. Octane in this case slows the burn rate. Simply use the lowest octane pump gas that will not let your motor knock and it will make the most power because you are using the fastest burning fuel. This is in simple terms as Im not a chemist and have seen this explaned in more tecnical terms on the Sunoco web site and the Unical sites. This is pretty much the accepted facts for pump gas, now race gas is totally different. You are correct that the 87 burns much cleaner than the 93. ::)

[r6_philly]

octane dictate the ignition point (temperature) rather than the rate of burn. As compression rise in the chamber, the pressure of the air/fuel mixture rises. Lower octane pump fuel have a lower ignition point. So what would happen in a high compression engine is that the air/fuel mixture may be compressed so much that the internal temperature passes the ignition point of the fuel BEFORE the plug sparks. Hence pre-ignition and the knocking. But if your motor can use 87 octane gas and not knock, it will have a better chance of burning throughly thus burning more clean. If you use too high of an octane in a normal motor, it may not ignite all that well because of too low compression, thus loosing power when you use 112 octane race gas.

Actually rate of burning actually have to do with the content/make up of the fuel. So is the power release potential of the fuel. Oxgenated fuel can produce more power per unit because it will release more energy when it is burning, because of the content.

I do want to know the difference between MR1 and the Untimate 4. VP claims the same power gains, but there is gotta be some differences.

My bike showed 4 extra hp's and a slightly better time to power curve when using MR1, dyno'ed within 5 minutes after switching from pump fuel.

[Decreasing_Dave]

My bike showed 4 extra hp's and a slightly better time to power curve when using MR1, dyno'ed within 5 minutes after switching from pump fuel.

Hey Philly,

Do you have a pipe on that R6 and what are you using for jetting?  I've been running VP Performance 101 and my R6 has been running great.  I tried VP Ultimate 4 and I had a big hole right off idle.  It was really hard to launch or get out of turns smoothly.  

I'm running stock jetting for the 2000 R6 with the exception of the needles being shimmed .020.  All I have is an M4 slip-on.

I'd like to jet to run Ultimate 4, can you render advice

TIA,
D. Dave

[r6_philly]

I have a Micron full system. Dynojet needles and 142 main jets. It is still a little rich with pump gas, but when you but in MR1 it actually leans it enough to keep the line close. I think I am going to try 140 mains from Dynojet. Needles are set to 3 from the top.

From what I learned at the dyno, if you want to set up for race fuel, jet your bike a little richer at midrange, but not a whole lot. So when you run pump gas it is a little richer, and it would be just right with race fuel. The MR1 gave it a little extra everywhere above 8-9 k with a total of 4 hp on top. But what is more important probably is my bike got to power about 1/10 second faster with the MR1, which might mean half a bike length coming out of corners  ;D

What was interesting: I raced last season with a mixed kit. It ran great and got me some good times and finishes. But when I put it on the dyno, it was REAL rich, and was slow to power. The curve on top was great, fat and free, but accelaration sucked. It didn't really feel that way, but comparing the dyno graph really told the story. Just goes to show how it may feel one way and be another  :o

As for the hole, I have a huge hole between 6-8k that no matter what jetting I used, was still there. MR1 mixed it half way, but with pump gas there is about a 10 hp drop. It may be the pipe I guess. But I think most R6's are soft below 8k and you will see a hole one way or the other. Just don't go below that :) gear it right and never get out of power

[Super Dave]

Hey, Dave...

I've got a Micron full system for a pre '02 R6.  Interested?  It was used for some dyno testing my '03, but it doesn't fit with bodywork.

Drop me a note?  visionsprt@netwurx.net

[MightyDuc Racing]

C112 VP is what I wound up buying from them Dave.  Gonna mix it 50/50 with 93 pump gas and see how it goes this weekend.  Thanks for all the help. :)

[Super Dave]

C12...  Ok, that would be decent.  T111 is what we bump guys to in SCCA, etc that use C12...  I think that will be a good start for you.

[MightyDuc Racing]

So I done good?  At least for now anyways? ;D