OFT Basic tuning procedure

[Kodename47]

Right, I wouldn't like to see any leaner than 12.7 at full throttle, you're unnecessarily adding heat to no real gain in power, which in return will make you more knock prone. Where did you get a figure of 13:1 from?

Also, why are you changing tables as low as 0.8? You're never under 1 on full throttle.

The reason the car is changing fueling so much is due to the LTFT caused by the MAF being off. 0.8 is right in the CL to OL changeover area so if you change the fueling there the trims will have a big impact.

Seeing the kc learn table drop is a sign of knock, 2 degrees pulled is a fair bit.

Stop just stabbing in the dark in the hope to achieve a target you've not set. Put an original OTS map back on the car and spend a few weeks reading and learning. Then start again. There is so much info about that just not bothering to learn seems idiotic.

[stugray]

If you are playing with OFT, I think the best suggestion (you may have already) is to compare your base map to the various stages of OFT tunes.

By looking at how they modify the base for each stage, you can see some of the logic behind the changes.
In RR the compare ROM feature tells you which tables are different and you can look at "difference" maps that reflect only the changes from one map to another.

[jamesm]

Take your time, make small changes that you can log the results of, and know what you're looking at when you do. Don't listen to people who tell you not to try. You'll never learn anything (beyond general tips and tricks) reading on a forum. Get out there and do it, just be smart about it and take it slow.

The first thing you need is accurate calibration. Scale the maf properly in closed and open loop so that you're hitting targets with ltft turned off. Don't rely on trims to hit fuel targets, as they won't do so consistently.

You can absolutely tune timing on this car without a dyno (so long as your not on ethanol). You'll hit the knock wall on even the best 93 octane looooong before you reach mbt. You sound like you have a decent idea of what you're doing and have the right approach. Just keep doing it, and remember the process. Slow and steady wins the race.

If you need any help or want a second set of eyes, feel free to shoot me an email.

[Grip Ronin]

noo map A on romraider is safe mode. you should leave it be

[HSayaovong]

Originally Posted by jamesm

Take your time, make small changes that you can log the results of, and know what you're looking at when you do. Don't listen to people who tell you not to try. You'll never learn anything (beyond general tips and tricks) reading on a forum. Get out there and do it, just be smart about it and take it slow.

The first thing you need is accurate calibration. Scale the maf properly in closed and open loop so that you're hitting targets with ltft turned off. Don't rely on trims to hit fuel targets, as they won't do so consistently.

You can absolutely tune timing on this car without a dyno (so long as your not on ethanol). You'll hit the knock wall on even the best 93 octane looooong before you reach mbt. You sound like you have a decent idea of what you're doing and have the right approach. Just keep doing it, and remember the process. Slow and steady wins the race.

If you need any help or want a second set of eyes, feel free to shoot me an email.

Thanks, I might take you on that offer and hit you up someday for tuning advice,
Also thanks to everyone with their great idea and suggestions. All the response was exactly What i was looking for.
Any additional tips,tricks and technical know how is greatly appreciated.
Keep them coming.

[EAGLE5]

Originally Posted by HSayaovong

Even with "infinite octane" fuel wouldn't you get knock once you advance the timing so much so that this fuel is ignited to early before top dead center? Which would produce knock snd if you log for knocks and keep away from advancing to far how would you destroy your bottom end? (I'm not challenging your advice, I'm trying to understand my own understanding on the subject).

To my understanding without a proper aftermarket wideband o2 sensor most of my afr teaching is probably inaccurate anyways, that's the main reason why I should be monitoring for knock, correct?

If you take advance too far with race fuel or something that can handle without knocking what normal gas cannot, you can end up increasing the cylinder pressure high enough to bend a rod or do something else bad. You can also very easily start losing power.

Since the OFT tunes already have a lot of work put into timing, you're probably not going to get much by playing with timing. If anything, you'll probably muck it up and lose power. You might even break something. More advance is not necessarily better. Now if you made significant mods to the car, that would be a different story.

Oh, and you never said what fuel you're using. With 91 or 93, you probably will run into knock before driving up the cylinder pressure too high, at least at high rpm. At low RPM, I don't know.

[HSayaovong]

I'm on 93oct. But what I've noticed is that there must be some kinda of primary limiter or something of that nature that keeps you from starying to far from the ots tune.
You can't lean it to much or adjustments will be made in ltft and stft for the difference in what the ideal afr it thinks it needs. That must have something to do with the maf scaling that you guys were talking about..*any links to more info on how to adjust the MAF scaling on romraider?* step by step tutorial would be awesome.

Also, I'm not looking to go all out and change everything about the safe ots maps that shiv provides. I'm only looking to ride on the knives edge of the tunes since the ots are made with a great deal of provisions to ensure compatibility with most vvehicles, i want too kinda undo what shiv's margin of safety.

*would be great if @shiv chimed in with the exact steps he took to input the margins of safety so that people like me can slow creep up the tune for more powwa.

I also would like if any of you guys that have oft and have done your own tunes to share it..i think shiv would be fine with tune sharing, that's the point of open source tuning right?

[TopGearSolutions]

Originally Posted by HSayaovong

Even with "infinite octane" fuel wouldn't you get knock once you advance the timing so much so that this fuel is ignited to early before top dead center? Which would produce knock snd if you log for knocks and keep away from advancing to far how would you destroy your bottom end? (I'm not challenging your advice, I'm trying to understand my own understanding on the subject).

To my understanding without a proper aftermarket wideband o2 sensor most of my afr teaching is probably inaccurate anyways, that's the main reason why I should be monitoring for knock, correct?

As others have touched on, blindly adding timing may not do anything for power (we've already touched on the safety aspect).

The keyword is "timing" and there is a perfect amount of timing known as MBT, maximum brake torque. That is the optimal timing where if you increase timing any further you no longer make any more power.

On this car I think you actually knock before you hit MBT but I wouldn't risk it personally.

The only way to advance timing is to do it on a dyno. At that point the only time to increase timing is when A) you are not knocking and B) extracting more power. It's VERY hard to do this on a street where you are not in a controlled environment such as on a dyno. Can it be done on a street, sure, but not recommended.

I would strongly advise you not to blindly add timing. There is also a threshold where you add too much timing and simply lose power. Other times you can add timing and knock.
Most tuners would recommend, including myself, that when you achieve MBT on a dyno you typically want to reduce ignition by 1-2 degrees for safety. (depends on the platform).

This safety comes into place for exterior changes, heat soak, octane differences, increased humidity, extreme temps, up hill loads and the like. You always want to leave a margin for safety, especially on a street vehicle.

It's a excellent you want to learn but keep in mind these engines are not bullet proof.

[jamesm]

you will never reach MBT on an 86 before you hit knock on pump gas. it just doesn't happen.

[HSayaovong]

Originally Posted by jamesm

you will never reach MBT on an 86 before you hit knock on pump gas. it just doesn't happen.

That's good to hear, since I'm on 93oct and i log for knocks i should be fairly safe to play with my timing"in small increments of course". Without to much fear of blowing something up right? And also by leaning base timing B alone for fail safe.

Also @jamesm , you don't happen to know of any tutorials on how to adjust MAF scaling do you? From the sound of everyone's response it seem that the wild swings in my stft and ltft are due to the maf scaling right?

[jamesm]

Originally Posted by HSayaovong

That's good to hear, since I'm on 93oct and i log for knocks i should be fairly safe to play with my timing"in small increments of course". Without to much fear of blowing something up right? And also by leaning base timing B alone for fail safe.

Also @jamesm , you don't happen to know of any tutorials on how to adjust MAF scaling do you? From the sound of everyone's response it seem that the wild swings in my stft and ltft are due to the maf scaling right?

you will run into knock before you reach mbt. you still have to be monitoring for knock, though . just add small increments and log twice as much as you think you need to.

if you have any significant fuel trims being applied you would correct that with maf scaling before doing any WOT tuning. ideally you should be able to get them down to within 1-2% and turn off LTFT in open loop so that you can have a more consistent open loop AFR. i'm not sure if the table to turn off open loop trims (or should i say, the one that works) is exposed in romraider/tunerpro though.

[Tromatic]

Really interested in this thread. The OFT is going to make it possible for people to grenade their engine, and I want to make sure I'm not one of them!

[jamesm]

Originally Posted by Tromatic

Really interested in this thread. The OFT is going to make it possible for people to grenade their engine, and I want to make sure I'm not one of them!

It'll happen. Not to smart people who follow best practices, though. Unless of course they have some really shitty luck or fat fingers .

[Toyota John]

I am interested in the flash tuning process too. I have done a little tuning on my MR2 with a Apexi PFC and have taken the advanced EFI 101 class as well as read some books on tuning. But much of them deal with tuning live being able to see what cell you are on, making changes and watching the differences. With the flash system that we are using this procedure won't work. I am assuming that to tune with a flash system you would make a logged run on a dyno, look at the logged data, flash and repeat. Anyone want to share their procedure that works for them?