101 wouldnt be enoguh octane for my buddy's car... but his isnt a street car either.... 468 n/a rat running b108 leaded gas

 

oops... meant 108 leaded gas... not b108... here is the pic of his car

 

Nice nice. What does it run time wise?

I think every one here now has a general understaning of what octane is and what it does. Keep in mind that if you do get slight pinging, and you don't have too many mods to the engine, don't assume that 101 is the only way to go. Look up Seafoam on this board. It will clean off all/most of the carbon on the pistons. It's amazing how little of a build up can increase the pressure that much.

For the guys with supercharged motors that are having the ping problem, 101 might be a good route, but keep in mind that the URD or 7th injector kit might be cheaper in the long run. I'm pretty sure that once you get above 100 octane (100% octane) it starts to get really expensive due to the fact that there are different and more expensive addatives in the gas.

Also, if you are looking for a way to boost the octane, look at adding tolulene to the gas. Search that as well and you'll find plenty of info.

 

What most folks don't realize is that by the time you can hear the knocking, its been a problem for a long time and already causing damage. You should know enough about your engine and its compression to determine that your going to need higher octane fuel.
If you run a blower or turbo, do the math and figure your effective compression ratio and if high enough, up your octane accordingly. Don't count on hearing the knock to tip you off that there is a problem. Also, if running a blower or turbo, check your timing periodically to ensure that its not off and causing knocking or other problems.
Also, Carbon does not cause knocking by increasing the cylinder pressure, it causes it by staying hot/glowing and igniting the fuel mixture.

Just my 2 Cents

MV

 

I didn't realize that about the carbon build up, I was told that it increased the pressure, but what you said makes much more sense to me.

 

4runer is just having a bad day!!

 

Greetings,
Here is another 2 Cents that I think is important. "The only dumb question is one not asked."
We are all here to learn and help each other.

I hope 4runer has a better day since he does help out so much.

Mv

 

I was only trying to get NXTacoma to read a page of text, as it seems he is mortally terrified at the thought of learning any more than the answer to the original question.