What does the computer change if you program it to run 93 octane and it gives you 20 more hp and a little better milage? Basicly what I am asking is when you put 93 in one the is programed from the factory you gain nothing and then a simple reprogram gives you the benefits, how? Just wanting to learn gas prices are taking a bigger and bigger chunk out of the pay checks, thats with my wife and me driving the 04 accord 4-cylinder getting 25 mpg in the city most of the time instead of my truck. Just curious, I live in Tennessee and gas has shot up 15 cents the past two days to 2.25 due to the huricane, what is around you all?

 

Ignition timing is one of the major changes that you want to program for 93 octane. This will benefit both for fuel economy, and horsepower.

Ryan

 

Hello CEE21,

Ignition timing is one of *many* changes we make when we tune these vehicles, whether we tune them for 87 octane, 89 octane, 91 or 93 octane.

As you go up in octane, it takes longer in terms of both degrees of crankshaft rotation and in real time to *initiate* the combustion event. Now once you get it lit, then the flame front propagates itself across the combustion chamber at about the same rate of speed. So you *must* run more ignition timing to use higher octane fuel properly, otherwise you will not get the benefit and can actually LOSE power and see the MPG DROP because the engine does not have enough time to burn enough of the higher octane mixture.

There are *many* things changed in our custom tunes for these vehicles, and spark advance is just one of dozens upon dozens upon dozens of things that need to be changed when doing a proper tune on these trucks.

Also, you cannot say that increasing the spark advance for 93 octane will automatically guarantee a gain in fuel economy - that depends on many factors, not the least of which is the actual energy content of the fuel being used and the condition of the vehicle. For example, many people take shortcuts and make the mistake of buying the cheapest gas they can find - especially when gas prices go up - which is one of the worst things you can do to *any* engine. That only assures you (in most cases) of getting a low quality fuel that is dirtier and with a lower energy (BTU) content. So you can very easily have a scenario in which your MPG actually drops - or stays the same - instead of going up.

Now what *is* true is that as long as you use a fuel of at least the same energy content, and do not drive the vehicle harder than you did before the tuning was installed, then yes - all else being equal you will generally see an improvement in fuel economy when the engine is properly tuned for the use of 91-93 octane premium gas. But then we also get fuel mileage gains in most cases in these vehicles when we tune them for 87 octane as well.

If you want to get the details on this, and find out just what you can realistically expect from our custom tuning these vehicles, or other ways to improve your truck's fuel mileage, please feel free to give us a call at our number listed below & we can go over that with you in proper detail.

 

Superchips_Distributer

Can you you explain a little bit more about what exactly more ignition timing is because I don't know what is going on when you say that? Also about how much of a benefit do you get if that was done only with the ignition timing and nothing else done?

Thanks

 

Anything I sit here & type to you is only going to cause you to ask more & more questions - just as it always has each time we have helped you in the past, and that is not the way to learn about this.

If you want to learn what ignition timing is and actually have a proper understanding of it, you need to know the basics of internal combustion gasoline engines - so I suggest that you go to your local library and ask the librarian to help you find some relevant material on "internal combustion engines," and specifically, for gasoline engines - and simply start reading. That is the way for anyone who does not understand the basics of gasoline engines to get that info.

Another thing I also strongly recommend is to go to any hobby store, or look out on a search engine on the Internet to find and buy a model that is called "The Visible V8 Engine." It is a plastic model of a complete engine that you build, with all the parts - crankshaft, pistons, valves, etc., that actually rotates so you can literally see those parts in action - it's a fantastic way to learn how an engine works and it's a great fun - the best way to learn what the various parts are and how they work, IMHO, and you must have that understanding to really get a grasp on just what "spark advance" (ignition timing) is.

Doing that model, along with reading a good book or two, will be a lot of fun and is by far the best way to get yourself up to speed on the basics of internal combustion engine theory. You will be amazed at how much fun that is, and how much you will learn - you will be SO happy you did that, trust me. Do that and you will thank me and thank yourself for doing that - and it doesn't take a lot of time, either.

Good luck!

 

Ahhh.. memories of my youth ;-))

Mike, I had that model and, the visible manual tranny one too.

Blew both up ( much like Neal did, but far less costly), by hooking that drivetrain up to a small dc electric motor and revving the crap out of it!

Fun until it went kaput. Blame my dad, who got me interested in auto and electricity/electronics ;-)). Well, he did pay for it - I was after all far too young.

Good advice on the education aspect. Beware, it also generates ever-more-sophisticated questions!

Cheers
Vic

 

Hi Vic,

I never even saw a "visible" manual transmission model - cool! I'll have to see if they exist any more.

Actually, the very first of the "visible" engine model series I had when I was a kid was the one for the Mopar "Slant 6" - yes, they actually made a "visible" Slant 6 model, and that was more complex of course, and *way* cool. Now that one actually came with an electric motor and a battery back so you could just hit the switch and the engine would rotate automatically - so cool.

I have never seen any of today's "visible" engine models have anything other than a hand crank to turn the engine over with - though I haven't really looked hard, and the hand crank is certainly sufficient to allow one to see all the parts moving and how they interact, etc., I do like the idea of the battery-powered electric motor to spin the visible engine model like that.

I too, did mods like you're talking about to some of those models - connecting a powerful electric motor with too much voltage supplied and blew up a number of those models - I even built a little "car" to put it in and tired to make a powertrain - but I was far too young & really didn't have the ability to make it work right, I just kept breaking parts. First lessons in hot-rodding and pushing parts way past their design limits, I suppose.

Thanks for your post - very funny, that brought back a lot of memories, and now I have to search out to see if there are any "visible" transmission models in existence today, too!

 

I put together one of those engines.

I did something wrong though because it runs backwards.

Instead of using gas, it makes gas.

 

For starters Mike I have done the reasearch several years ago on how a gasoline engine works and even diesel engines, rotorary engines 2 stroke engines and transmissions. And also I have built a visible v8 engine for my younger brother. Yes we have gone through this before and everytime I ask you just one other question you blow me off saying you don't have time to answer when you had time enough to write a big long post of bull sh*t about why you can't. Plus I am a Senior in one of the toughest engineering schools and I already have to learn a lot of that stuff on my own and don't have much time for stuff I want to do. So you can either challange my intelligence again or just answer my question with just two sentence. I am sure that you can answer it.

Here's a good web site for you to go and maybe you can learn to be more respectful of people who ask questions wanting to learn.

http://www.howstuffworks.com/

 

No need to go off on Mike... He obviously spends hours upon hours each week reading and contributing to this great community. If he were to have to explain to each member just how a combustion engine works, he wouldn't have time to tune our trucks
And to be honest, I agree with Mike; If you don't understand the very basics of gasoline engines (ignition timing is very basic in the realm of engine tuning, and not just performance tuning; ie tuning-up an engine, etc) go read a book. I prefer to see us using Mike's time for what he's AWESOME at - helping us get MORE POWER Not explaining "what exactly more ignition timing is."

 

Well put, bamorris2.

Cee21 - the link you provided would have answered a bit of your own questions. Here's some more:

http://www.centuryperformance.com/timing.asp

http://racingstudebakers.com/ignition_timing_.htm

.. and so forth. 5 seconds on Google and got about 1,160,000 English pages for ignition timing.

So how can you expect Mike to administer a classroom on this obviously complex topic. NO one would have that kind of time to do that here, and it's unreasonable to expect same.

If you are indeed a serious student, and truly have the desire to know - teach yourself.

Mike does not need me or anyone else to defend his position - one only needs to review some of the thousands of his posts where he exhibits almost inhuman patience with us as he repeatedly explains the wonderful world of (F150) perfromance ;-)), and retains a great sense of humour while doing it!

A class act, and very much appreciated by all his loyal customers and visitors on this site.

Cheers
Vic

 

This topic is slipping away from Chips and Programming toward emotions.

Here is an excellent link to a document that goes into detail on gasoline quality, including detail on the relationship between octane and spark advance.

http://www.ethanolrfa.org/pdf/Gasoline.pdf

As has been mentioned, there is a lot of information already available on the net.

I think more or less anyone can get away with a minor modification of an exhaust or intake. However, fiddling with some of the more complex performance modifications should be left to people who are as fond of their internal combustion engines as they are their pets.

After all, if you install a performance mod, you are the mechanic of last resort as far as making sure it works and adds value. Your vendor may help, but you are the one with the wrench in hand.

Enjoy.

 

Thanks Les - great article!

Me, emotional? Nah.... this is just too simple to make more complicated ;-))

Cheers

 

Yea your right MGDfan this is too simple to be complicated. Yet some how you all have managed to make it that by not being able to read my post thourghly. So let me break it down for you, just don't think about engines for a minute and think about the use of the two words "more timming". It makes no sence, for example you would say "I need to make my timming better." Anyhow I figured out what you cave men were trying to say without looking at any of those sites because I know how a ignition system works. It should have been stated as "advancing the timing which means the spark is initated sooner". Now that statment would have taking just 10 seconds to type so what was the problem? You all are about as useful as Ashley Simpson's singing.

 

CEE21

Why flame? Try using the search feature on this fine forum for answers to the very basic questions you have. Flaming ain’t going to get you anywhere