Timing 14* or 16*

[Hethj7]

You can always find him over at theRiceHatersClub .

[Falcons Talon]

Originally posted by Hethj7
I completely disagree here. There is absolutely no benefit from running a higher octane fuel than you need. You are just throwing money away.

First off, that link is very informative. I had read something like that years ago, and this falls right in line with my knowledge.
I'm no expert here...probably far from it, but I am looking at something from this excerpt which I took from the link provided.

Use of a fuel that has a higher octane than is required by the engine and the way it has been tuned will result in unburned deposits being created and left behind in the combustion chamber, and on top of the piston.

Provided that you are tuned to run 87 octane gas (10*), yes, you may be harming more than helping by running a higher octane.

If you advance your timing (tuning) to the point of detonation, your are creating a unstable environment that the high flammability of 87 can not control, but by simply using a higher octane level, you can remain tuned at the higher advanced timing because the higher octane can stabiulize the fule to burn at a more controlled rate.

So the million dollar question is, what is the timing advance that will provide the best performance, and what octane do you need to run that timing without having a meltdown.

[Hethj7]

Falcons Talon - You are correct in what you are saying. I was more referring to 88fivepointoh's post:

On any High Performance motor, 93 octane is best, you won't always here the detonation, but it doesn't mean its not happening.. If you move up time from stock, 93 is best.


As you pointed out, this statement is true only if you are tuned to run with 93 octane. To just say "if you move time up from stock, 93 is best" is not sound advice. Depending on your set up, altitude, etc., you may be able to run 89 or even 87 octane depending on how far advanced you are.
If you do advance to the point of having detonation occur, try running 89. Just because you have played with the timing does not mean you need to run out and start pumping 93 octane into your ride.

Also, don't just assume that you are tuned for 87 octane at only 10°. That is just a very safe factory setting and many cars can bump up their timing a few degrees and still run 87.

To respond to titanium92's original question, I would say on a basically stock mustang to advance the timing as much as possible while still being able to run 87 octane. IMO, the performance gains on a stock vehicle will be minimal when advancing the timing far enough to warrant running high octane fuels. To me the added cost of the fuel wouldn't justtify the 3 or 4 more HP you might squeeze out of the car.

[88fivepointoh]

Well IMO, i have seen engines smoke head gaskets, and pistons from silent detination.. i have seen it visible on dyno runs and it was told to me by Augustino Racing In Canada that once timing is advanced, a higher grade of fuel is best. These cars were designed in a time where fuel was richer at the pumps and todays fuel sucks.. That is my .02cents on this discussion.

[Hethj7]

Originally posted by 88fivepointoh
Well IMO, i have seen engines smoke head gaskets, and pistons from silent detination.. i have seen it visible on dyno runs and it was told to me by Augustino Racing In Canada that once timing is advanced, a higher grade of fuel is best. These cars were designed in a time where fuel was richer at the pumps and todays fuel sucks.. That is my .02cents on this discussion.

That's cool. I have just heard different from other sources which I believe are knowledgeable. We can just agree to disagree on this one .

[titanium92]

Hey great feed back guys.......I'm still up in the air if I should adjust the timing though....everyone seems to be making good points.....aahhh...lol. Too good of points so now i'm more confused....lol.

[88fivepointoh]

I think we all agree to bump up your timing.. its just the fuel rating we all have different opinions of..

[Hethj7]

Originally posted by 88fivepointoh
I think we all agree to bump up your timing.. its just the fuel rating we all have different opinions of..

I will agree with that statement

[GhettoPop]

Originally posted by titanium92
Hey great feed back guys.......I'm still up in the air if I should adjust the timing though....everyone seems to be making good points.....aahhh...lol. Too good of points so now i'm more confused....lol.

run 87, bump up timing till u hear pinging, then turn it down a degreee or two. continure to run 87 and keep an ear out for pinging, aka, marbles in your engine