100 octane will be harder to ignite and will not burn fully during the power stroke. Therefore it will foul the engine sooner. Performance will suffer.

Power is BTU's not octane. Octane is just a number that indicates the fuels resistance to ignition and burn rate.

What a foolish waste of time and money.

 

Lately I've been running 87 ethanol free in my carbed 2002 S/S and it runs like a scalded dog on it.

 

I run 87 in my bike and it runs just fine. No need to waste money at the pump on a low compression n/a engine. Just my $0.02

 

Since 2006 I have run all my bikes on E10 87 octane. Every TC from 88 to 120's.

I have 18K on the 120 in my 15 Freewheeler. Runs great.

I do use high flow intakes with stock mufflers, iridium plugs, stock exhaust, oil cooler, tank lift (cooler heads) and modified AFR.

All the two wheelers get 50 mpg except the 13 Street Bob with a 120R which is at 47+ mpg and the Freewheeler is at 42 mpg. A 12 RGC got 52 mpg and the 14 Road King gets 53 mpg.

The other thing is that I do a slow 3K breakin.

 

Having run race gas such as VP in my drag race car, and knowing more that a bit about fuel requirements for a given motor, the only way to "tune" a motor for higher octane fuel is more compression. Yeah you could advance the timing, but most likely it won't go any faster. Higher octane fuel does not produce any more energy than lower octane fuel as some of the others have pointed out. Octane is merely a fuels resistance to detonation, and not a performance indicator.

A 14-1 compression motor would detonate itself to death on 91-93 octane fuel, where a 10-1 motor would be quite happy with it. Conversely, putting 100-110 race fuel in a 10-1 motor will only make it run sluggish and maybe hot, or at best, make no difference at all.

Although I'm not a walking catalog on VPs products, (personally, I won't run VP. But not because of quality. I could go on and on about their pricing and subsidy practices) the fuel most likely fouled the sensors on your Audi because most race fuel contains lead, zinc, phosphorous and other chemicals not compatible with sensors like that

 

exactly what mike says above ..i run 100-115 in a couple supermoto bikes i have but they are all hc stroker motors...also might want to add on the 100 vp you put in your audi was it leaded or unleaded they do make both!

 

Good point.
Leaded gas in any production car or motorcycle (stock or street modded) will pit valves and ruin heads, if not the motor in short order.

Octane is used to eliminate or reduce ping or detonation. If your bike doesn't ping, don't increase octane.

High compression or advanced timing increases detonation, but even 10.5:1 Harley engines rarely need anything more than 93. The exceptions are sportsters and Evos with builds that push valve operation limits. Some TC motors meet this criteria, but those guys already know this stuff.

High octane gas comes under three basic labels. Racing, aviation fuel )AV gas), or marine gas.
AV gas is usually leaded and should never be used in a motor that has factory valves.
Many race tracks, and some hot rod shops sell both leaded and unleaded.
I never paid attention to marine gas in terms of lead content. I suspect that newer boats and personal watercraft need unleaded.

 

LOL, no sir! Pretty much anything which doesn't have oxygen sensors or catalytic converters can run leaded fuel without harm. Leaded gas is actually kinder to valves and valve seats than unleaded.

Leaded gas and oxygen sensors aren't a happy mix, so that's typically where a problem will show up first.