Race gas question... help

[spymoto]

I tried searching for this topic... sorry if it was asked before!

I've been using straight Sonoco race gas,110 octane in my 03 R6. I've got a power commander, full exhaust and possibly a thinner head gasket (think thats what the previous owner said)

I Dyno'ed my bike at the Races this weekend at Road America. I only got 94.5 HP on the first run and then tried a different map and got 95.5 HP, 1+ HP thoughout the whole power curve. Isn't this kinda low??? They said 123HP stock in the specs (wheel or crank???) They didn't have air pushing into the ram air intakes, but don't think it would more than 5-10 HP off because of that.

The question is...

!) Does this HP look right for an R6?
and
2) Should I mix my gas 50/50 race and pump? if so, race and 93 or ???

Thanks much!!!

[rogers1323]

1) The 123HP in the specs would be talking about crank HP.

2) If you ran it on the ASRA dyno, then it should show low.  ASRA uses a Factory Pro dyno, whereas all the numbers you'll see will talk about DynoJet numbers. 

I don't remember the difference, but they should read 10% to 15% different (I think).  Someone else can come on here and confirm that part.

I don't have any experience with race gas personally, so I'll leave that to other people as well.

[GSXR RACER MIKE]

123 Hp would be at the crank for a stock engined R6. I think the 95 Hp rear wheel is kinda low for that bike (but it also depends on the type of dyno), do you know if the bike was actually dyno tuned on that fuel and they created a custom map for it, or are they generic maps? Also, have you tried something like VP U4.2 in that bike?

[spymoto]

Yes it was the ASRA dyno.

It wasn't ever tuned for that bike. They are the generic maps off of the Dynojet web site. the lower one was for the full system Hindel exhaust, and the other was full system exhaust with race head gasket and cam timing change.

I've only used the Sonoco race gas because it's the only thing in my area. If you have any ideas on a better gas, let me know and if you mix it or run it staight.

Thanks!

[Spooner427]

I am not an expert so take this for what it's worth.

The higher the octane the less explosive it is. You will actually make more HP(on the same tune) with lower octane but your engine will knock, over heat and blow up quickly. If your maps are ment for normal 92 pump and you run 110 you will lose HP but your motor will run alot cooler. So you either need to get your bike tuned with what ever fuel you plan on running in it or find out what fuel your maps were tuned for. If you get your bike tuned I wouldn't use 110 because that octane is for pretty built motors. So either use 92 or 100 unless you can spring for the oxyginated fuels like U4.2 which is where the real HP is at.

[Super Dave]

Hey, what's new!

Yeah, 110 leaded race gas isn't very good in a high reving motorcycle engine.  It isn't even very good in a high reving race car engine.

Lead in racing fuel is good for power as it makes the flame front burn uniformly and then more complete if it has time.  The composition of most leaded 110 and up racing fuels causes them too burn too slow, however, in a lot of performance applications.

Next, racing fuel purchased out of any pump that is sourcing fuel from a non sealed container should always be suspect.  It's delivered by truck, and the truck would have carried any number of products in it before it delivered that fuel.  There's no consistency in that.

So, what should you do?  Well, you could run the 110 with about two or three gallons of pump gas.  First, that reduces some of the execessive amounts of lead and "heavy" chemicals found in those fuels.  Next, a pump gas has a pretty fast flame burn.  Further, a lot of pump fuels are mandated to have an oxygenate in them.  That's going to help on power on the bike.


My 2003 R6 that I raced from 2003 through last year would make just about 99HP on Power Mist TO137 racing fuel.  Probably makes it about 113 to 115 on a dynojet dyno.  If you were getting 95.5HP, Mike, I think you were doing pretty well on power.

[Super Dave]

The higher the octane the less explosive it is.

Octane is only the resistance to ignition on its own.

But some fuels are composed of chemicals that as the octane is increased, the speed in which the burn comes is unable to be completed in the period allowed.  Back to a bike engine, think about how actual time the mixture has an opportunity to burn at 14k.  Quite a bit different from a street rod at 3k. 

[spymoto]

Thanks for the info everyone!

Looks like I'll be swithing to a sealed can race gas. The VP U4.2 is were its at? Hopefully not too expensive, if it is any other fuels that are the best bank for the buck? Also,If I go that way, am I going to be using that staight and no mix?

I'd like to get my bike tuned properly. About how much am I looking at to spend and any good places to take my bike to in the Madison/Milwaukee/Chicago area? Any referals???

Also, Do I want to find a Dyno that has air for the ram air or doen't that make much difference?

Thanks again!

[EX_#76]

1) The 123HP in the specs would be talking about crank HP.

2) If you ran it on the ASRA dyno, then it should show low.  ASRA uses a Factory Pro dyno, whereas all the numbers you'll see will talk about DynoJet numbers. 

I don't remember the difference, but they should read 10% to 15% different (I think).  Someone else can come on here and confirm that part.

I don't have any experience with race gas personally, so I'll leave that to other people as well.

The number is .12 (or 12 percent) lower that a Factory (ARSA) dyno will read from a dynojet set to read out SAE corrected HP.

Hope that helps

Guy

[Ducati23]

Octane and gasoline energy output are not directly related. A fuels ability to produce power is based on three specific factors, the fuels specific heat, oxygen content and lead content. Chemical additives to fuels generally have an effect on one of these three areas and octane, the resistance to explode or ignite. Employing a fuel that has more octane than required can have a negative effect if this causes the fuel to not completely burn as it should. This would show up as reduced power output. Your R6 would probably do well with U4.2 and proper mapping. An estimate of output would be about 110 or maybe a little more on a Dynojet dyno based on your ASRA dyno numbers of 95.5 on the Sunoco stock pump fuel. Only testing and tuning will give you a good real number.     

[MELK-MAN]

 take the ASRA and multiply by roughly 113% to get a dyno number your used to seeing. That is just how it works. Thus with your bike 95x1.15 = 107 .4 or so on pump gas. For what it is worth and as others have noted your probably wasting money on high octane pump gas on your bike. Now, if you mapped the bike for U4.2 or Mr9 you would see an additional 5hp or so and 112hp for a 2003r6 with just a thin gasket and MAYBEY cam timing is pretty darn good. The BEST i ever saw out of my 03 and 04 r6 that had national caliber SS build was 116. The 05 got bigger throttle bodies and did get into the 118 range but that was with a total rebuild. New cases, pistons,etc.
Get some VP fuel and remap.