I got my truck filled with 93 and running level 3. It says in the book level 3 is for 91+. Is there anything i should to compensate for the extra octane or am i fine leaving it how it is?

I love this thing




And no i'm not buying custom tunes anytime soon

 

leave it how it is!
...it says minimum 91........but better with 93.

 

Just fill it up with 93 octane.

 

It says right there on the next page or so that you need to bump the timing. One degree for every 2 octane wasn't it. Go to the timing and do a +1.

 

It won't hurt anything leaving it though. Not to mention, the manual is not always right. How does the manual take into consideration elevation, air temperature, etc?

 

If I remember, it tells you about elevation and how to take it into consideration. If they did not think it safe to do so, I garuntee, they would not tell you that you can.

 

you don't have to bump the timing at all with the canned tune!
It says you need a minimum of 91 but can see improved performance with higher.....like 93.
When customizing the settings you can bump it .5 for every 1 octane rating.
NOW.......don't take this the wrong way guys, but the gas in the U.S sucks. 93 octane isn't any higher octane than the 91 we have in Canada .....therefore I wouldn't bump the timing much if any at all. Don't flame me for saying that, but there are alot of tuners that will agree with me on that.
I have seen a difference myself in burning both U.S and Canadian gas in my truck. My old canned level 2 tow tune would run like a champ on Canadian 87 octane......but like crap unless I went to 91 in U.S stations!

 

That may very well be true, but the thing was tuned from Edge to run on the US 91 octane. Yes, you can run it on level 3 with 93 octane just fine, without bumping the timing. But why would you not want to bump it? It is there to use and to use more efficiently. I ran mine for two years on 93 octane bumped 1.5(before I got custom tunes) and it has been quite happy. When I got the custom tunes, Bill tuned it to run on 93 octane, so if I ever run across some 91 and have to put it in, I'll do a -1.00. You can run Level 2 on 91 octane without bumping the timing, but why would you? The same applies in my mind for running 93 on level 3. I will bump it to get more out of it and have it run more efficiently.

 

we are not arguing with you Bluejay....what you say makes sense. But he asked if he would be fine leaving it the way it is........and looks like we all agree that the answer is yes. Can he improve things by making some adjustments? - yes,likely a little bit.
Also Bluejay.......what I was saying is.......I don't think your 93 octane is a true 93 (more like 91 or 92). Because I know your 87 isn't where it should be. Bill actually told me to bump my timing ahead on my 87 performance tune simply because I am running Canadian gas.
Ofcourse you are right though in that all of the tuners have taken gas inconsistency into account when writing the canned tunes and have left a buffer in there!

 

Chris it sounds like American gas isn't what the rating says. It sounds more like Canadian gas is above what they have got listed. I've had quite a few cars on the dyno, with all sorts of different fuels, and all of them are what they say on the pump.

 

Since we're on the subject of octane and tuners...I happen to own and fly my own aircraft, and even though it's kinda illegal (only if you get caught...it's all about highway tax) I run 100LL AVGAS (100 octane low lead aviation gasoline) in our '68 Firebird hotrod. It's cheaper than racing fuel, plus one of the quirky things about aviation fuel is that it's guaranteed to be at least 100 octane - with test showing it 110 or better (some blends even go up to 140). We tune the carbs for it and it runs just fine, but that goes to show you how much variance there is in the fuel octane. Commercially sold racing fuels are notorious for this and usually are less than stated octane levels (a reason we stick with avgas).

One question I wanted to shoot by you guys...I know that most of the custom tuners on here can provide a custom tune for any octane really, but since we can adjust the timing manually would you recommend adjusting a 93 performance tune up 3.5 or 4 degrees for the 100 octane? Or is it too risky to be a test driver and just get the tune OR not even use anything in the trucks over 93? If any, I would only use a small amount of the high octane gas while at the track, and it would be on an empty tank. Thanks guys...

 

Well, you could be right about that Thumper. Bottom line is...........it seems there is considerable inconsistency!

 

What a great thread!

Personally, I'd bump the timing by 0.5 and see what happens. If it works well, I'd try another 0.5 and so on. And, I'd be listening VERY closely, as well as looking at the idle performance.

Back when I had canned tunes, I tried advancing the timing by 0.5 and got a "hunting" idle behavior. To be fair, that was when I had fairly old firmware in my Edge (now a Gryphon) at the time. I thought I could bump the timing since I live at 2500 feet. Well, I took the funny idle as a warning and set it back.

I'll have to try it again now that I've got custom tunes, but I suspect Bill has already taken care of that for me. I know I get better performance and mileage with his custom tunes.

Just a tiny bit of detonation is not harmful. But, an underadvanced spark wastes power and gas.

On the subject of octane - my tune is an 87 octane tune. Driving in Colorado, I used 85 octane gas with no problems and no audible detonation, pulling a trailer over 11,000 ft passes.

To NXTRockr - isn't avgas kind of expensive to put in a car?

- Jack

 

Well guys I increased my timing .50 of a degree and running Canadian 87 octane with 87 Gryphon perf. tune. Truck seems fine with it and I can't hear any pinging under WOT. Interesting??

 

how long ago was that?