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Pro Cal Octane & Updates

KingLeonidas

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So I have two questions I'm hoping others can help me out with. So due to 93 octane being $6+ a gallon :rolleyes:, I was thinking about going back to 87 for the time being. So can you run 87 on the tune or will it do damage? Or should I flash back to stock? I like the shift points on the tune better but I could do without it for a little while until prices come down. Nothing like getting 16mpg at $6+ a gallon. :LOL:

Also, I saw there was an update available for the pro cal when I plugged it into the computer. Has anyone experienced any issues with this update? Or know anyone who has had issues. I've been trying to find notes or information on the update but couldn't find much. I don't want to update my device with a bad/glitchy update.
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If you're going to run 87, flash it back to stock.

if you have E85 readily available, I'd throw in 5 gallons per full tank of 87 and keep the tune on. The procal can handle up to E30 mix and that would get you pretty much 91 octane which would be fine
 

DuneRunner

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Do not run lower-octane with the timing changes from the tune; the $ 50- $ 200 you are going to save is not worth the headaches later.
 

Brian_B

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Updates tend to remove features rather than fix things on ProCal and you cannot downgrade … I would not blindly install unless you see a change log
 

box986

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I only use ethanol-free which is only avail as 90-octane, so use a booster to increase it by 3. I have heard it is not good to run the tune below 92/93, but I have no proof of that. Hopefully a Ford engineer chimes in here...
 

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Brian_B

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I only use ethanol-free which is only avail as 90-octane, so use a booster to increase it by 3. I have heard it is not good to run the tune below 92/93, but I have no proof of that. Hopefully a Ford engineer chimes in here...
If you read the fine print - ProCal requires 91, recommends 93
 

box986

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If you read the fine print - ProCal requires 91, recommends 93
I wonder though, what (if anything) would happen if someone runs below 91 for an extended time?
 

Brian_B

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I wonder though, what (if anything) would happen if someone runs below 91 for an extended time?
The immediate effect is that the ECM will retard timing and boost as it detects pinging.

Not a huge deal once in a while, the engine does this all the time based ln conditions.

The long term issue - the ECM and Pro Cal were programmed assuming 91 as a minimum. They want to start low and ramp up all the way to where they just start to detect pinging to boost performance.

By default every time you start up with lower than spec gas - you risk the pinging being more than slight as the engine has to retard to stop it. You have used gas below what the computer is assuming is already low.

Again - unless its extreme, every now and then probably won’t hurt anything. But do this all day every day, and that pinging can cause physical damage in the cylinders - high temps, pitting ln heads and pistons, etc.

Its the difference of tip toeing your way from the kiddie pool out out to the limit versus jumping straight into the deep end and hoping you can get to a spot you can touch the bottom before you drown.
 

box986

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Brian_B

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Any proof of this? The ECU should adjust
I'll start by saying I don't know of any specific Bronco instances. There are a few cases of burnt valves and such, but I don't know that's attributable to octane/ECM tuning per say.

But... two things

I'll have to see if I can find some pics. We run a lot of big engines at work, and I've seen this exact thing and the damage it causes when you look inside a cylinder. It's very obvious. Looks like someone shot the piston crown with a shotgun or something, and if it gets extreme, can blow holes through it - looks like someone hit it with an acetylene torch. Ping/Knock will destroy an engine, even at low levels, if you give it enough time.

Second thing, which is Bronco/Ford specific. If you hook up a OBD2 scanner, you can find an PID called Learned Knock Mod. This is a setting Ford uses to try to remember what octane you have in your vehicle, so that every time you start up, the ECM isn't having to re-learn your octane rating from scratch. A value 0 zero is stock default - 87 octane for standard tune, 91 octane for Pro Cal, could be others for custom tunes. A value of -1.0 means the engine hasn't detected any ping and has advanced timing as far as it will: you are getting maximum performance. A value of +1.0 means the ECM has retarded timing as far as it can. There is a minimum value to how far the engine can retard for ping before it just can't retard any more and you just have to live with knock.

Go run 87 for a while and look at your LKM value, see what you think.
 

vrtical

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I wonder though, what (if anything) would happen if someone runs below 91 for an extended time?
nothing, it will reduce the timing, its not like you completely fall out of the fuel map ranges, you just end up in a different bucket.
 

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In addition to octane requirements for FP tunes, stock Broncos need 93 just to make factory stated hp. That's stated in Ford docs.

In order to truly accurately blend to any octane I developed the (paid) Android app, Octane and Ethanol Calculator, https://octanecalc.com/ . It uses a totally novel algorithm based on real, high quality, laboratory test data letting you blend to an actual octane goal (or % ethanol as desired). Although few and far between, the other apps, web sites, tables or formulas for octane blending are utter nonsense/garbage and inaccurate. There are plenty of options (calculators) to blend to an ethanol goal, but that shouldn't really be anyone's true goal. A given ethanol % will typically have a possible range of octane values of about 5 points!

Like the other poster said, use 91 minimum and 93-94 if blending up with E85. You'll also need to find out your exact local (and perhaps seasonal % ethanol in your E85, as unfortunately, it is never 85%).
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