VegasGold

I changed my 91 Race Tune to the 93 Race Tune on Saturday. I had the 91 Race Tune for several months. Much better at everything over stock. We only have two stations here that carry 94 octane. After hearing how everyone claims the 93 Race is so good I finally decided to switch and find out for my self...

Well, after three days I must say I notice a difference. A much better pull at every lever over the 91 Race tune. I did not think it would make that much difference but, I was wrong (first time). Much better power and seat of the pants all the way through the rpm...This is how the Mustang should have come from the factory. I only hope Ford has a more powerful engine on the next redesign. I am addictive to this power. I only want more now. I will never settle for anything less that this power level when I purchase another car. Yes, I can add a supercharger etc. Which I may do next year or so. I would really like to just buy one with this kind of power and then be able to mod it up...I Love this feeling. Feels Free and I want no less on the next Mustang...

I am not sure how Doug develops these tunes. The tune is the 93 Race. I have 94 Octane. Can I advance the timing 1 degree or something for the added octane I have? Also, would it make any difference or create problems? Thanks for your input. I thought I seen something like this in another forum...

I would not want to change it back to stock any time soon. What a disappointment that would be. Like driving Miss Daisy...

jjs06gt

When Doug was down here last month i pretty much asked him the same question, and the way i took it was that was about as much "tuning" as could be done with that high of an octane fuel.

m05fastbackGT

When running a higher octane fuel.. you do not need to advance the timing ! it's only when you run a lower octane fuel, with a higher octane tune.. that will cause your air/fuel, to run at an unsafe lean condition.

ttbit

Uhmmm.. You can try to add some timing when you have more octane. 93 to 94 probably isn't going to allow that much more. Advancing timing is how you get the power out of higher octane fuel, otherwise you would get nothing more by switching fuel. If you run too much timing you will get detonation. I think people get confused with air/fuel and timing as some tuners add more fuel to help reduce possible detonation. Adding too much fuel is just a waste.

Clark Kent

yes i have wondered the same about the 94 octane, is it worth it to advance the timing one degree, and if so how do i do it?

RedDragon777

i am going to order a 91 octane tune just for traveling, i know alot of places do not carry 93 octane and last time i asked he said he could make an 89 octane tune, but like i said, this would only be for traveling, for the track it is 93 race only LOL

GottaHaveIt

I like it in Oregon by the dunes where they race atv's and such there are a couple stations in smaller towns that have 100 % octain humm now what would that do.

m05fastbackGT

And you completely missed my point ! what I meant was..it's neither necessary, nor required because, advancing the timing from 93 to 94 octane ? is so minimal, that your not going to notice any SOTP difference anyhow. Therefore, why even bother wasting the time to begin with ? when you can achieve the same results, by running the Bamachip's 93 race tune, with 94 octane fuel, in which the knock sensors will automatically advance the necessary timing, in order to compensate for the slightly higher 94 octane fuel, you'll be running..

ttbit

Maybe everyone else understood your sentence structure better than I did and it was just me.

I can see what you are saying now. I am not convinced that the EEC advances timing much when it doesn't see knock. It will retard the timing as necessary when it does though. Also, it's not about your mixture leaning out on detonation. Advancing timing only increases the chances of the mixture igniting before you want it to. Having a lean mixture can cause detonation problems too though.

No worries.

Bullitt995

I couldn't understand him either in his first post.

Also I'm pretty sure the stock computer isn't going to add timing on it's own.

ttbit

If it does add timing, it would be yet another function to disable when adding a supercharger or having an aggressive tune. The last thing you want is to finally have everything dialed in and safe and then have the computer think it is OK to advance your timing. It's like Microsoft thinking it knows how to index your drive.

theedge67

The knock sensors will only retard timing, it will not advance anything. If the sensors don't sense knock, they don't do anything. The computer does NOT advance the timing until it senses knock either. It advances the timing as far as it is programmed to, depending on what octane it is programmed for.

If it is programmed for 87, it will use timing tables for that octane, and advance it as far as is generally safe for 87. If by chance there is some knock using those tables, the sensors kick in and retard it a little.

m05fastbackGT

First of all, I'm not absolutely certain as to whether or not the knock sensors actually add timing, as in the sense of advancing the timing, on it's own ? I'm assuming they only add timing, when the computer either senses knock or a detonation issue. So perhaps, I'm getting the entire timing curve terminology mixed up with improper air/fuel mixtures, such as running higher grade octane tunes, with lower grade octane fuels ? ie.. running a 93 octane tune w/87 octane fuel..Anyway, hope this clears up any confusion, that I may have caused from my first post..

theedge67

The knock sensors do not add timing, they can only back it off (retard the timing).
Advance timing = adding timing = making the spark plug fire sooner in the combustion cycle.
Retard timing = backing off = taking timing away = making the spark plug fire later in the combustion cycle.

air fuel ratios are only slightly related to timing issues. The mix of gas to air is a seperate issue to the timing of the spark. It is a little more complicated than that, but that is the easy version.

It gets more complicated....Having the timing way off can cause a wideband o2 sensor to read the a/f as way off, even though the actual gas to air mix going into the cylinder is correct. The fuel just isn't having time to burn completely, leaving lots of o2 in the exhaust, making the sensor read rich. This is why the top tuners get the big bucks, cuz they can figure this complicated mess out.

m05fastbackGT

Once again, I stand corrected..seems that I had it all backwards lol. So if I understand correctly ? only the computer itself, is able to advance timing, that is.. if it senses knock correct ? and the knock sensors themselves, are only capable of retarding timing, whenever they sense knock or detonation issues and I also agree with you 100 % as to how complicated of a mess this can become, in which I'll leave it to the experts, such as Doug from Bamachip's and Brent from Brenspeed, to figure out lol.

ttbit

Here are a few basic rules, but by NO means is this a complete list. I am not claiming to be any kind of expert. This is just from my experience.

The knock sensors tell the computer if there is detonation/knocking.

The computer retards (takes timing away) when it is told there is knocking.

The computer controls the timing/fuel and all those engine controls. The engine sensors (all types) don't control anything. They just tell the computer what they are sensing.

The timing the computer uses is based on tables programmed by human beings based on all kinds of engineering and testing. The computer is programmed to slightly modify some of these to a percentage, based on what the sensors tell it. This is done as all environments and cars are different to an extent and this allows the computer to run the car more efficiently.

Aftermarket tunes tweak the factory tables and other settings based on dyno testing with different fuels and aftermarket parts.

Timing tables are generally tweaked for more advanced (higher numbers) timing on higher octane tunes.

Octane is a magic part of the fuel we use that helps control the speed of fuel burn.

Computers don't magically know what kind of fuel you put in the car.

My experience in dyno tuning is in the EEC-IV and supercharging. There are all kinds of new controls in our cars, which makes it more challenging to get right. I have some real-world experience with tuning and I rarely post a reply as I figure someone with more experience will usually chime in. I always feel bad for posters that ask these type of questions only to be answered by people who have never played with an EEC before or do not know tuning basics. I am not trying to be mean here either, so please don't take it wrong.

M05, I think you understood it a little better before the thread started.

I think what Theedge and Bullitt are saying are correct, but I have never seen code for the newer computer myself.

Bullitt995

Since I work in the refining industry, I'm going to be picky. (It has turned into that kind of thread)

Octane isn't actually a part of the fuel, it's just a number to describe it. There a few different formulas to find octane, hence why europe has different octane numbers at the pumps.

m05fastbackGT

I'll put it in this way..the knowledge that I've learned, concerning these timing and spark curves ? are from Doug at Bamachips..However, before becoming one of his customers, well over a year ago..I didn't know squat about what an aftermarket tune was, nor did I have a single clue, what an air/fuel ratio even meant, when concerning all this new technology bull crap lol. In which I'll be the first to admit, there's still quite a bit I still don't understand, but I believe that I've also come a long way since then, as well. And because of fellow Stangers, such as yourself, Bullit and The Edge ! that knowledge continues to grow that much stronger, through your feedback and support..And support, is really what these fourms are all about..

blkstang06

Right on, Rocky!! Thats what this all about, brothers of the Stang running across the plains of the Internet in one harmonious herd !... well most the time........

VegasGold

Thank you everyone for your input. I too am learning every day. This new engine is something...Who would have thought computers would have played such a role...I remember the old 4 barrel...Seems like last year...