[bradleydadley]

I'm racing an '03 SV650S this year at the track. Her ECU is set up for 1/2 race fuel- 1/2 92 Premium pump gas or approximately 100 Octane. Aviation gas is 100 octane and $3.99. Race fuel 110 octane at $12/gallon. Has anyone experience with using av gas in an SV?

 

[Rednarb]

Good gawd why? Are you running high compression or something?
http://en.wikipedia.org/wiki/Octane_rating

 

[bradleydadley]

Well, Dyno says... horsepower 78...

Gen1 rods
PCIII
M4 Exhaust
Supersport setup

Went for Sunoco R110 mixed with 92 premium. W/Power Commander and Sage Wilkinson's tune... she purrs nicely!

 

[SVcsuRAM]

I have experience running blue gas in a lot of different applications. Mostly because its free, my dad manages a airport and i get all the fuel that gets sumped to do a visual inspection. It smells really cool but doesn't affect performance enough to pay for it. Plus I have heard that it can be bad on valves. But Jet A runs good in a diesel so I do that too.

 

[svtime]

EDR sells Sunoco for less than that. I pick it up at Blue Flame Oil at 111th and Foster for $8.50 a gal

 

[pahHONEix]

I work/teach at our local airport in town and every now and then we get guys (usually squids) at the front desk asking if it's okay to use 100LL in their bike. We usually tell them "No, because it's not made for it." In reality they can put whatever they want in their bikes, we just advise against it.

Aviation fuel (or "100LL," "avgas," "the blue stuff," etc.) is leaded gasoline (the "LL" in "100LL" stands for "low lead"), so I'd guess that using it in an engine built to run on unleaded gas wouldn't be too good for it. It's dyed blue so it's not easily confused with Jet A, which is usually straw colored.

But yeah, 100LL does smell awesome.

 

[eteach01]

won't matter unless there is a catalytic converter involved... but a waste of money and loss of HP if you don't have the compression up around 11.5 to 1.

 

[andyauger]

This is a tricky one. Higher octane will not give higher HP unless the true compression ratio (not the static compression ratio) is high enough to bring the higher octane fuel close to detonation. The article linked above is pretty good.

Static compression ratio is pretty meaningless in this case. Static compression on the SV is 11.5:1, but it runs just fine on 87 octane. The reasons are complex and include combustion chamber shape and intake charge turbulence.

True compression ratio varies with RPM. The engine doesn't pump with 100% volumetric efficiency at any time, so the true compression ratio is considerably lower than the static. Cam overlap is another factor limiting the pumping capacity.

You got 78 on a dyno with that fuel mix. What did you get with pump gas? Gasoline without ethanol will be more energy dense than gasoline with ethanol. That's one benefit of using racing or aviation fuels.

 

[Currently]

Welcome back Andy! :thumbsup:

 

[nyc rugby]

Welcome back Andy! :thumbsup:

+1

 

[Nox]

This is a tricky one. Higher octane will not give higher HP unless the true compression ratio (not the static compression ratio) is high enough to bring the higher octane fuel close to detonation. The article linked above is pretty good.

Static compression ratio is pretty meaningless in this case. Static compression on the SV is 11.5:1, but it runs just fine on 87 octane. The reasons are complex and include combustion chamber shape and intake charge turbulence.

True compression ratio varies with RPM. The engine doesn't pump with 100% volumetric efficiency at any time, so the true compression ratio is considerably lower than the static. Cam overlap is another factor limiting the pumping capacity.

You got 78 on a dyno with that fuel mix. What did you get with pump gas? Gasoline without ethanol will be more energy dense than gasoline with ethanol. That's one benefit of using racing or aviation fuels.

Huh? ???

 

[SpeedisaVirus]

Doesn't look like you have enough into the bike to be concerned with race fuel to me...

 

[Spirits]

myfriend who is a pilot used to give me old cans of 82UL he used to get for cheap. That stuff ran fine mixed up a bit, but I got no power gains from it. At least I didnt feel any.