how effective would 110 octane be for my car?

[Royalty]

it has just come to my attention that thre is a local gas station that sells 110.

i read that a higher octane gas is better for us turbo cars but what exactly will it alow me to do? I'm runnin a catless exhaust so i'm not worried about it eatign up my cat

 

[Shadowfax]

I'd imagine that there is a decent write up of this somewhere on the site... however the simple answer is this -

depends on your boost.

Octane is how well the fuel resists preignition - spontaneous combustion so to speak. You don't want what you are compressing in the cylinders to decide to explode as the piston is still moving up (at least, not TOO early ).

Timing advance is when your spark plug ignites the mixture in the cylinder before the piston reaches Top Dead Center- this creates more power granted, but too early, and you've got the explosion working against the movement of the piston - a bad thing.

The fuel is what ignites when the spark happens- but it's fuel- if you get the temps hot enough (or a single carbed up hot spot ) then it will ignite before the spark. That means it ignites before the timing advance even wants it to. This is bad, and generally your motor doesn't love you for it. They like to break apart violently if you let it happen really often

So as your temps increase in the cylinder the fuel needs to resist that desire to spontaneously combust. The octane rating is that resistance. The higher the number, the better it resists- which means you can cram more air into the cylinders and it will won't go boom until it should. The problem is that A) unless you are often at high boost, you're wasting money, B) most of the time you have no need of that high octane, and you actually don't do yourself any favors running it- high octane typically contains lead (the reason lead was in old fuel ) and lead likes to kill O2 sensors, also higher octane burns slower than lower octane (or the other way around, can't recall right now)- and so you get worse mileage, and technically less power (though only by a bit).

The long and short is this- if you don't NEED it, don't run it. If you are on a stock IC with 20+psi and stock fuel with your 14b- then yeah, at the track, it would probably be a good idea to run it while at the track. As for daily driving. VERY few people need it.

High octane makes up for poor IC, slightly for not enough fuel, and mostly for poor tuning. It's smarter to run it at the track when you might think- I'm .05 from my goal ET- if I crank boost just a TAD more then I might hit it - basically to cover intentional abuse

 

[1993eclipseGS]

Turn the boost up alot more without getting knock.

 

[c5chris]

Your turbo can only function efficiently within the boundaries of its compressor map. If you have a big turbo, then you can push it harder. If you are stock T25, your 110 octane will only help you a little. Your intercooler needs to be a good design too.

You will have little or no knock, your engine will not pull timing UNTIL your intercooler hits its efficiency limit and starts to heatsoak. Your engine needs to pull timing then not due to fuel but due to air temps/density.

 

[Royalty]

damn decent explinations all of you, thanks

 

[lrall]

110 octane is race gas usually, it can b run but its really expensive to buy and just use as a DD

 

[4pistons]

I'd be a little skeptical that a gas station is selling real 110 octane because it is usually leaded. To legally sell it they must be sure it is used and sold only for off-road use which would be difficult to do and justify the low volume they would sell.

It COULD be possible to have 110 non-leaded but I'd be skeptical.

Rick - '91 GSX

 

[MNGSX]

http://www.nhrasportcompact.com/2004/rules/fuels.html

List of fuels..

there are some unleaded high octane fuels... Most are going that way due to the EPA.