I'm not at stock boost levels. I'm putting 292whp/298wtq on a 91 octane reflash @ 23psi with headers, 3" TB exhaust, and k&n drop-in.

I think the 100 octane won't be a waste - especially if I decide to turn up the boost a little.

-M

 

It's probably safer to run 100octane at the track since you'll be at sustained boost levels. I've heard a few people recommend this because it's less likely to knock due to heat.

 

Picked up 50whp going from my old 91 octane tune to a 100 octane tune. Untuned there was no difference though obviously.

 

No it will not give you more HP. If your car isn't knocking or you aren't tuned for it you don't need it.

Nothing like throwing your money away on something you don't need.

 

just go get tuned to c-16

 

It has to do with burn times, higher octane takes longer to burn, so your actually wasting part of the fuel(unburned) if you run stock tune/boost. And like others have posted AFR's generally get richer with the high octane leaded fuels. I run 100 at the drags/roadcourses, drags I run higher boost(25.5 psi) with no knock and trackdays i run 22psi but keep the 100 in there for extra safety, but you asked about power on the original post. I notice when I run leaded at the drags my plugs start to foul on the street until the race fuel is emptied out of the tank, but I run very little at a time.

 

yes it will give hp

 

Negative.

Higher octane gas does NOT raise gas mileage.
Higher octane gas does NOT raise power output.

 

Ofcourse, proper tune on 100oct can give more HP than 91oct tune.
While running 100oct tune the tuner can easily increase boost w/o worring about knock.

I am not tuned for 100oct. But I can share my experience.
On 91oct tune I was at around 21psi. I filled my tank with hundred and w/o touching my MBC I noticed my car is doing 23psi. Same thing with cold nights. WOOOOOOOOO Magic.

 

This thread got completely flipped around. People are talking about tuning on blah blah octane. The question was "does adding higher octane gain IMMEDIATE power". Nothing to do with how much boost you are running, nothing to do with how much boost on what tune and what octane. It was a very simple question.

 

exactly...the only way running a higher octane fuel is going to make more power is if you are already running too high of a boost level for the octane you are currently running

the rule of thumb is that you want to run as LOW of an octane as possible without detonation for optimum performance

 

Higher Octane fuel is heavier than 93 and will NOT give immidiate HP. The reason that people get a race tune is beacuse with the higher Octane you can add timing and more fuel at higher boost levels eventually getting the HP gains one looks for with race gas. With out a race gas tune there will be no gains.

 

The question was answered allready earlier in the thread. The answer was NO.

I couldn't help mentioning the fact about the tune. Sorry it hurt you that bad.

OP your theory is right, your friend is an idiot.

 

Just mix 100 oct with 91 to get roughly 94. If 93 is available then I wouldn't bother. My car seems to love a "splash" of race fuel mixed with the **** poor 91. Oh and if you are making more power with 100 oct then your tune may be too aggressive and your ecu is pulling timing when you running straight pump gas.

 

its safe to say you're friend is uninformed.