93 octane?????

[Graygoose]

In a perfect world yes it will pull timing to save the motor. Have you seen the top ringland of the stock 5.7 pistons? There is no room for error and only takes once to crack the ringland. It is advised by every tuner to use the correct fuel for the correct tune.

yes, helped tune a few cars

[yt]Q6YX_tU8WBU&feature=BFa&list=UU_wkxuRkfoWExvVL9tDNfXg&lf=plcp[/yt]

An agressive tuner will push the envelope, a good tuner you can get away with it easy trusting the computer. The new BAMA tuner on his 2011 5.0 GT is agressive, but safe.

 

[KGBIGCOUNTRY]

Apples to oranges there, your talking a stock ringland on a stock truck vs im assuming built forged motor with more resistance to the combustion forces.

Crappy pic but can ya tell how narrow it is?

 

[Graygoose]

Not really, both are ran on a dyno to get 12 on A/F ratio, timing, spark and fuel pressure. Carb'd just is done manual, where computer does a computer controlled car. A stock hypereutectic piston will hold 100-150 shot of NOS with good injectors. A little detonation is fine, but on a 'good' computer controlled truck, knock sensors will retard timing 1-2 degrees.
A ton of stock pistons handle a small dose of nitrous, and it's much worse than a small detonation for a few milliseconds.

 

[KGBIGCOUNTRY]

A canned 93 tune is set more aggresive then you start out on a carbed race car. Your Mustang on the above pic was started on a know safe base fuel jetting with a know set of advance then pulled onto the dyno and then tuned from there. Guessing small adjustments made till you found the edge then backed it some and bam done. The canned tune is setup and the computer is sopp to tame it back down if an issue is found. In other words he is starting out more aggressive and in hopes the computer will figure out a lower octain fuel is in there and revise the maps, backwards from that Mustang.

I watched my truck on the Dyno the whole time it was tunned. Also watched a few race motors here and there

 

[KGBIGCOUNTRY]

09smokinhemi I would check with DSP on the change of tune option, they know the limits to there tune better then us.

 

[09SMOKINHEMI]

Sounds good

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[Graygoose]

Ask Justin from Black Bear, 90% of his GM tunes are 93, where 90% of those run 91 max octane. He says the computer replies on knock sensors to back or adjust timing, relying on octane, air/fuel, altituude, etc. Why do most handheld have a 93 tune when 90% of the US doesnt have 93?
Look at a piston for a longrod 406, you'll see less head above the ring land on most OEM style pistons.

If a handheld is really aggressive, then I wouldnt use it period. Most are pretty mild. Install it and run it and see where the timing really is, I bet you still see a very conservative timing ramp.
Tuning a carb'd vehicle on a dyno is really no different than a handheld. All they do is get a stock PCM, run it to where you have decent gains, then make a platform that can be downloaded into any base PCM. Then mass produce and sell it.
A custom tune takes each car's specifics and makes adjustments for each car. You're pretty much buying a 'cookie cutter' tune with most hand helds. If you detonate off a 93 tune on a hand held, I wouldnt use it, nor ever tune for it.

But IF I were to use a handheld, and download for the 93 tune, I wouldnt be scared of running 91, IMHO.

 

[09SMOKINHEMI]

Well in checking on some of the local racing forums, they make mention of the same thing in that they run 93 tunes on 91 octane, and that they're able to do that "because of the air here", whatever that means....

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[Graygoose]

Well in checking on some of the local racing forums, they make mention of the same thing in that they run 93 tunes on 91 octane, and that they're able to do that "because of the air here", whatever that means....

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Because the computer compensates. Trust me, run the 93 tune and run 91, you won't have any issues. Get other sited and almost all run custom tunes, by Nelson, Black Bear, etc and most all are 93 tunes, while they run 91. I did a live tune in Wichita, KS with Justin from Black Bear Perfromance, he lives in LA and travels around the states and does live tunes and teaches EFI Live classes. It made my Yukon with a little 4.8 run like a power house. Wasnt even close to what more timing would do, but if I ever found good 93, it would have ran even better.

 

[09SMOKINHEMI]

Sweet looking ride goose

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[Graygoose]

Sweet looking ride goose

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Thank you sir.

 

[smiley]

Ask Justin from Black Bear, 90% of his GM tunes are 93, where 90% of those run 91 max octane. He says the computer replies on knock sensors to back or adjust timing, relying on octane, air/fuel, altituude, etc. Why do most handheld have a 93 tune when 90% of the US doesnt have 93?
Look at a piston for a longrod 406, you'll see less head above the ring land on most OEM style pistons.

If a handheld is really aggressive, then I wouldnt use it period. Most are pretty mild. Install it and run it and see where the timing really is, I bet you still see a very conservative timing ramp.
Tuning a carb'd vehicle on a dyno is really no different than a handheld. All they do is get a stock PCM, run it to where you have decent gains, then make a platform that can be downloaded into any base PCM. Then mass produce and sell it.
A custom tune takes each car's specifics and makes adjustments for each car. You're pretty much buying a 'cookie cutter' tune with most hand helds. If you detonate off a 93 tune on a hand held, I wouldnt use it, nor ever tune for it.

But IF I were to use a handheld, and download for the 93 tune, I wouldnt be scared of running 91, IMHO.

Superchips has both a 91 and a 93 so I would assume there is a reason personally but not sure.

 

[Trupiano]

Well hell, if you can go 91 on a 93 tune, then you can go 87! Common sense right? = P




Tapatalk'in

 

[Graygoose]

actually, yes you can use 87, computer just ******* timing more, which would equal less power. But you can use 87.

 

[Trupiano]

Think I'll stick to my 93. I don't want my truck's timing retarded or anything, it's already dumb enough with it's locked PCM :********:

 

[09SMOKINHEMI]

Lol

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[glass3222]

One thing to remember is that for the computer to retard the timing from the signal of the knock sensors, some detonation has already occurred. This may be ok at time or 2, but for it to continually do this, it will lead to damage.

There is a reason that ALL tuners say that for a 91 Octane performance tune to use 91 octane or higher, same with 93.

Also, even with handhelds, all vehicles respond differently to a tune. Dodge vehicles seem to be more tempermental than others. I would data log with any tune (canned or custom) to make sure there is nothing funky going on with MY vehicle. If there is, run higher octane or reduce timing.

 

[KGBIGCOUNTRY]

I like Trups idea I may have to do that will my motor, I mean the knock sensors will catch it and I can save some money on fuel.....

 

[(S.M.R) 101]

Ok my SC tuner has the option for 87 octain or 91 octain I don't have a 93 option...... And up in the great states of NY and PA it's either 87, 89 or 93.. So I just started running 93... I have been running the 89 (since there was no 91 octain at the pumps) but I like the feel of running the 93 feels alot better than the 89..

 

[LoadedLaramie]

Might be a little late chimig back in but when i was going thru this with my 06, i dataloged a few WOTs to see the differance and t was showing every sign for detination while i was running 89 on the 91 tune. I addwed a powerwire and it almost instantly fixed t with the rest of the fuel learning curve smoothed out over the next week. But it was pulling nearly 6 degrees out and still was hitting. Yes a comp vehicle will resolve its own but it will still hurt itself over time. I blew the rings in my 383 stroker ears ago by accidently putting in 89 in it instead of 93. Cruising up the highway, stomped it, barked the tires and ****, smoke rolled ot thue back. I let off and limped home.