Starting Advanced OAR and ignition correction discussion

[Stkid93]

I’m new to the fist platform. I understand the basics of what OAR and ignition corrections do. But I would like to know more about how they work together. For example my fist is currently tuned on e30, but I always add a little extra ethanol so it’s really running on an e38-e40 mixture, it has a -1 OAR. And maxes out on 2.5 degrees of timing added via the corrections. When my fist was on the 93 map, it would add up to 4 degrees. Why does the 93 tune add more timing than e30?

I also understand the fist constantly ups timing to maximize economy and performance. So will the car add more than the 2.5 degrees? Or is 2.5 the max the car will add? and if the car will add more timing, how much will it add

now let’s say the OAR drops to .75, will the maximum ignition correction drop from 2.5 down to say 1.5 or 2 degrees? Do the oar and corrections work in tandem like that?

Feel free to add more to this discussion, I would like to start an advanced discussion on this stuff, way past the basics.

 

[Dialcaliper]

My basic impression is that Corrections and OAR are basically to timing what fuel trims (STFT & LTFT) are to fueling and AFR, and yes, they work in tandem

When there’s no knock, the ECU will attempt to advance timing corrections on each cylinder and when it detects knock it will retard timing corrections. If the global max correction value persists somewhere besides near the middle (0 to -1), it will contribute to a shift in the OAR value, which has a global affect on timing. (OAR also takes input and has affects on other ECU parameters besides just timing)

Like LTFT, OAR also has boundaries on where it will change (based on coolant temp, load and RPM ranges) so that it reflects the average fuel quality at more normal operating conditions, whereas corrections can occur rapidly at any point in order to protect the engine at specific operating points.

The end goal is that OAR shifts the map globally so that that ignition corrections remain small and able to respond with authority to protect the engine - both parameters have a limited range so as not to deviate too far from the original map, which can result in unexpected behaviors.

It’s the job of the tuner (Ford or aftermarket) to design the basic ECU map so that with good high octane fuel, OAR shouldn’t need to deviate from near -1.0 unless you actually run into bad or low octane gas.

If you were tuning DIY with accesstuner or another system, you can use corrections and OAR as one tool to adjust your timing maps, in the same way you can use AFR and fuel trims to adjust your fueling maps

 

[cidsamuth]

This is completely tuner dependent.
Even the OAR is treated differently. My first tuner, OAR would start at -.65 and get to -1 quickly and sit there.

Second tuner, OAR would change constantly, going up and down.

My latest tuner leaves it locked at -.8 … it never moves.

From what I’m told, there are many ways to skin the cat with these …. and timing with these cars, from what I understand, has even more options.

 

[Jabbit]

Use a trusted tuner, then disconnect the AP and stash it in the glove box. That's my method of tracking.

 

[TyphoonFiST]

I’m new to the fist platform. I understand the basics of what OAR and ignition corrections do. But I would like to know more about how they work together. For example my fist is currently tuned on e30, but I always add a little extra ethanol so it’s really running on an e38-e40 mixture, it has a -1 OAR. And maxes out on 2.5 degrees of timing added via the corrections. When my fist was on the 93 map, it would add up to 4 degrees. Why does the 93 tune add more timing than e30?

I also understand the fist constantly ups timing to maximize economy and performance. So will the car add more than the 2.5 degrees? Or is 2.5 the max the car will add? and if the car will add more timing, how much will it add

now let’s say the OAR drops to .75, will the maximum ignition correction drop from 2.5 down to say 1.5 or 2 degrees? Do the oar and corrections work in tandem like that?

Feel free to add more to this discussion, I would like to start an advanced discussion on this stuff, way past the basics.

Read up* Straight from Alex@stratified a reliable source


https://www.stratifiedauto.com/blog...ons-in-your-high-performance-ecoboost-engine/

 

[Stkid93]

@Jabbit

sorry, but isnt the accessport meant for more than just loading a tune onto your car? there is a reason they put the real time gauges on it right? Being able to monitor your engine gives you a huge advantage over those who dont and can save your car. for example, if you get into it and you notice your boost is 40 psi on a stock turbo, or you a/f ratio is way too lean, or your oil or coolant temps are way too high. A great example is oil temp, a lot of people say you shouldnt get into boost until your oil temp is at operating temp (170-180 degrees). When the stock temp gauge on the fist is in the middle reading "operating temps" your oil is still only at about 120 degrees. Even the coolant may not be completely warm. The accessport tells me when the temps are actually good.

There are literally a dozen things that can go wrong at any point. and even if something isnt going wrong. it still tells you useless information like i said earlier. shouldnt we take advantage of the technology we have and the capabilites the accessport gives us? i just feel like im driving blind without it, even if nothing is going wrong. Having the accessport hooked up gives me so much peace of mind that if something does go wrong. I can potentially save my car.

 

[Erick_V]

@Jabbit

sorry, but isnt the accessport meant for more than just loading a tune onto your car? there is a reason they put the real time gauges on it right? Being able to monitor your engine gives you a huge advantage over those who dont and can save your car. for example, if you get into it and you notice your boost is 40 psi on a stock turbo, or you a/f ratio is way too lean, or your oil or coolant temps are way too high. A great example is oil temp, a lot of people say you shouldnt get into boost until your oil temp is at operating temp (170-180 degrees). When the stock temp gauge on the fist is in the middle reading "operating temps" your oil is still only at about 120 degrees. Even the coolant may not be completely warm. The accessport tells me when the temps are actually good.

There are literally a dozen things that can go wrong at any point. and even if something isnt going wrong. it still tells you useless information like i said earlier. shouldnt we take advantage of the technology we have and the capabilites the accessport gives us? i just feel like im driving blind without it, even if nothing is going wrong. Having the accessport hooked up gives me so much peace of mind that if something does go wrong. I can potentially save my car.

This is why boost cuts are set up. If you pop a vacuum line off and overboost the tune will cut throttle. I understand what you're saying but unless you're running your setup to the ragged edge then you will have the AP stashed away. 99% of people are running tunes with moderate timing and safe fuel blends if not one fuel (91/93). OAR is set up to limit timing if the sensors see knock. If your tune hits -1 quickly most likely you are running conservative-ish timing. There is failsafes for a lot of these "issues" that we will see on a daily basis. Also, everyone with a modified car will still not cold start the car and beat on it despite the coolant temp reading in the middle. FWIW when I did my track day the main parameter I looked at was coolant and that's it. Even though I was running an E30 blend I'm cornering at 60-90 and don't have time to look at AFR's lol. Lastly, oil temp isnt an actual value. It's calculated on coolant temp and load hence why some people run gauges. I run E30 and still have my AP stashed away, Jason isn't searching for records on a flash tune. He makes it so we can beat on our cars and still be safe. I haven't had my accessport mounted for almost 2 years. 5 years and 75k miles later of 27-28psi peak boost on E my car is still running fine, no need for paranoia.

 

[Dialcaliper]

@Jabbit

sorry, but isnt the accessport meant for more than just loading a tune onto your car? there is a reason they put the real time gauges on it right? Being able to monitor your engine gives you a huge advantage over those who dont and can save your car. for example, if you get into it and you notice your boost is 40 psi on a stock turbo, or you a/f ratio is way too lean, or your oil or coolant temps are way too high. A great example is oil temp, a lot of people say you shouldnt get into boost until your oil temp is at operating temp (170-180 degrees). When the stock temp gauge on the fist is in the middle reading "operating temps" your oil is still only at about 120 degrees. Even the coolant may not be completely warm. The accessport tells me when the temps are actually good.

There are literally a dozen things that can go wrong at any point. and even if something isnt going wrong. it still tells you useless information like i said earlier. shouldnt we take advantage of the technology we have and the capabilites the accessport gives us? i just feel like im driving blind without it, even if nothing is going wrong. Having the accessport hooked up gives me so much peace of mind that if something does go wrong. I can potentially save my car.

Most things that will actually grenade or kill and an engine in a single driving session happen too fast for you to do anything about anyway. As said above, the oil temp reading on our car is inferred based on coolant temperature and not from a real sensor, so that’s out as a useful gauge.

Yes, it can be kind of useful, especially on a track day to monitor stuff like charge air temperature to monitor for heat soak and other small stuff, but in general, the standard sensors on a modern car are all you really need to have available to check for imminent failure (basically, RPM, coolant temp, oil pressure). AFR and timing adjustment are all automated now, so even that’s not strictly necessary to monitor.

Accessport gauges can also be incredibly useful for diagnostics when something seems off, or a problem has already occurred (like a head gasket or misfire), but you are by no means crippled without the extra gauges.

Extended gauges are useful if you’re going “rogue” and doing your own tuning maps, which is a whole other can of worms.

I keep an eye on a new tune for a while, but generally just keep the AP in the glovebox in case I need it. I may pull it out or rig something up if I ever get out to the track.

 

[Jabbit]

You make some good points. I use a different type of gauge when I'm on track, and I only monitor coolant temp. Nothing else really matters to me.

 

[M-Sport fan]

You make some good points. I use a different type of gauge when I'm on track, and I only monitor coolant temp. Nothing else really matters to me.

I don't even open track this car and I use the UltraGauge 99.9% just to monitor coolant temps, and once and a while glance at the boost/vacuum levels.

I do not even have this plugged in all of the time, since it does draw some current even when the engine is off, and I do not want it pulling any juice from my AGM battery (which I still do not know if our alternator/generator is supplying enough current to or not, as it must be over 14.2 volts in order to fully re-charge an AGM ).