Tuning Technical Point #1 - What is MBT timing?

[802SHO]

@mattr66usa At what point are you going to actually disprove what I’m saying? Because so far, every response has either agreed with the underlying physics or narrowed the scope without refuting it. If there’s a specific technical error in my reasoning, point it out directly.

All else equal” is a classroom condition, not a real turbo engine.
On a boosted, speed-density EcoBoost, exhaust drive pressure, residuals, VE, combustion phasing, and turbine efficiency are always changing. Treating MBT conclusions as if those variables are static is unrealistic.

Agreeing on MBT theory does not define a platform limit.
Yes, MBT is about combustion phasing for maximum torque. That does not make observed VE or MBT plateaus hard engine limits. Those outcomes are configuration-specific and move when exhaust constraints change.

VE and MBT shift with drive pressure, not just airflow or cams.
Rising exhaust backpressure increases residuals and pumping losses, degrading effective cylinder filling and spark sensitivity. That’s a turbine/pressure-ratio issue, not an intake airflow ceiling.

Methanol changes combustion and must be tuned for…every time.
Meth alters burn behavior, charge temperature, knock margin, exhaust energy, and pressure ratio. There is no valid assumption that “the car will sort it out,” especially when MBT conclusions are being drawn.

Observed plateaus reflect common configurations, not engine potential.
Repeated results across similar stock-location turbine setups describe a shared choke point, not a fundamental engine limit. Change turbine flow and pressure ratio, and VE/MBT move accordingly.

 

[mattr66usa]

No. I’m not jumping threads or changing topics like Mario from Mario Bros.

We already agreed on the simplified MBT trend only when all else is equal. My original and still-unanswered point is this: on a drive-pressure-limited, speed-density turbo system, methanol changes combustion energy, residuals, and effective VE, which means MBT and borderline timing no longer map 1:1.

Because meth is fuel mass and combustion modifier, any amount of meth requires explicit calibration. Relying on knock control or “letting the car sort it out” is neither safe nor technically correct.

If you disagree, the burden isn’t to redirect me to another thread — it’s to explain how introducing additional fuel energy without recalibration is not reckless on this platform.

Damn I didn't think you would give up this easily after all the BS you have been professing to be an expert on. I call you to the mat and you run..... Hope everyone can see you for what you are.

 

[802SHO]

Damn I didn't think you would give up this easily after all the BS you have been professing to be an expert on. I call you to the mat and you run..... Hope everyone can see you for what you are.

I didn’t run from anything. I answered your MBT question directly, acknowledged the simplified trend you asked about, and explained why it does not constitute a platform limit or justify not tuning for methanol. I posted the original 100% Methanol and GH Tuning Don’t Mix thread. You abandoned that. Made some more threads. We are here and you jump again to another one. You are the one avoiding. You are the one still unable to explicitly point out where my “BS” is wrong. I’m not wrong bc you say so. Prove it.

At this point, the discussion stopped being technical and shifted to personal attacks. If you want to continue, the door is open: identify a specific technical error in my reasoning and explain why it’s wrong. Otherwise, there’s nothing left to debate.

 

[mattr66usa]

I didn’t run from anything. I answered your MBT question directly, acknowledged the simplified trend you asked about, and explained why it does not constitute a platform limit or justify not tuning for methanol. I posted the original 100% Methanol and GH Tuning Don’t Mix thread. You abandoned that. Made some more threads. We are here and you jump again to another one. You are the one avoiding. You are the one still unable to explicitly point out where my “BS” is wrong. I’m not wrong bc you say so. Prove it.

At this point, the discussion stopped being technical and shifted to personal attacks. If you want to continue, the door is open: identify a specific technical error in my reasoning and explain why it’s wrong. Otherwise, there’s nothing left to debate.

Nope, not at all.... I'm willing to put it all out there but you have to start with the basic understanding on how these are tuned and you don't possess that knowledge it seems. You can either prove otherwise or learn in the process and I don't care which it is honestly. The problem is you keep saying things that are abstract and have no real application and are saying things that negatively impact my reputation. We can either start at the bottom where you can prove my fundamentals leading up to the way I tune for methanol are flawed, or you can stop saying things that are completely unsubstantiated. Your choice. You have a fork in the road. Which path will you take?

 

[kryptto]

I have tried to step in and allow both of you to save face, but stop the madness: meth is not “cooling only”

i’ve followed both threads. this needs to end because the “cooling only / no tuning needed” meth narrative is just wrong at a basic engine level.

this isn’t opinion. it’s physics and there is real science behind this I have been researching since this all started.

strike 1: meth is fuel, not magic water

fact: 100% meth is a fuel. stoich is ~6.4:1 vs gasoline 14.7:1

if you spray meaningful meth (10–20% fuel mass) and don’t pull gasoline, the engine runs way rich

that’s not “safe rich”, that’s cylinder wash / oil dilution / ring wear rich

widebands can correct some, but they’re not meant to compensate for a major unmetered fuel source


running stupid rich to avoid liability isn’t safety, it’s slow damage.

strike 2: no meth timing = no real gains

the point of meth is octane

the point of octane is reaching mbt timing

letting auto-octane logic “creep up” means you never actually hit mbt, especially on short pulls

you get the cooling safety net, not the power you paid for


that’s a deliberately neutered setup.

bottom line

small nozzle, mild meth? fine, pcm can handle it.
big nozzle, real meth flow? it must be tuned for.

calling meth “just cooling” is misleading.
it is fuel.
fuel requires tuning.

everything else is liability management dressed up as tech advice.

now some factful posts and sites since there needs to be less personal opinion and more direct referenced information

22 pages long and a great read: https://energy.mit.edu/wp-content/uploads/2008/01/MIT-LFEE-08-001-RP.pdf

this is written in plane ole English: https://grassrootsmotorsports.com/articles/watermethanol-injection-kit-tuning-aid-you-need/

so when I started working with my HP tuner I started paying for these courses I recomment Matt you pay for some lessons because I am sure they will tell you meth is a cooling only non fuel: https://www.hpacademy.com/previous-webinars/069-watermeth-injection-tuning-motec-m150/

I know I know diesel but regardless it still applies and would be great for @SM105K since he asked about it earlier. https://www.mdpi.com/2077-1312/13/5/949

and lastly a more technical read but very informative, after seeing the charts how could you or anyone say just cooling over tuning and making the changes for the PCM to adapt properly....

https://www.researchgate.net/public..._Turbocharged_GDI_Engine_Comparative_Analysis

Matt dude just admit to yourself u do this machination for your own preservation. less time adjusting for each daily driver car you tune for and for your liability in making the wrong adjustments.

we are not talking about the deviation of someone adding gas that has 92 and not 93 octane as an overly simple example. btw for both of you other than cheerleaders most of the main audience in these threads have tuned the fck out.

802 for your argument and I believe your position it would be best to cool off I get why you are angry misinformation like this makes it hard to stay on track and people start believing the non factual argument.

Matt dude, don't know ya but please this is grief posting at this point. the more you post the more you put yourself out for scrutiny and discredits your cache here amoung the tone and mean tons of referals members make to your business. but for all you say 802 sounding crazy, it's because his point is correct and I can see how it's making him crazy in. each post.

seriously enough everyone this is madness

 

[mattr66usa]

I have tried to step in and allow both of you to save face, but stop the madness: meth is not “cooling only”

i’ve followed both threads. this needs to end because the “cooling only / no tuning needed” meth narrative is just wrong at a basic engine level.

this isn’t opinion. it’s physics and there is real science behind this I have been researching since this all started.

strike 1: meth is fuel, not magic water

fact: 100% meth is a fuel. stoich is ~6.4:1 vs gasoline 14.7:1

if you spray meaningful meth (10–20% fuel mass) and don’t pull gasoline, the engine runs way rich

that’s not “safe rich”, that’s cylinder wash / oil dilution / ring wear rich

widebands can correct some, but they’re not meant to compensate for a major unmetered fuel source


running stupid rich to avoid liability isn’t safety, it’s slow damage.

strike 2: no meth timing = no real gains

the point of meth is octane

the point of octane is reaching mbt timing

letting auto-octane logic “creep up” means you never actually hit mbt, especially on short pulls

you get the cooling safety net, not the power you paid for


that’s a deliberately neutered setup.

bottom line

small nozzle, mild meth? fine, pcm can handle it.
big nozzle, real meth flow? it must be tuned for.

calling meth “just cooling” is misleading.
it is fuel.
fuel requires tuning.

everything else is liability management dressed up as tech advice.

now some factful posts and sites since there needs to be less personal opinion and more direct referenced information

22 pages long and a great read: https://energy.mit.edu/wp-content/uploads/2008/01/MIT-LFEE-08-001-RP.pdf

this is written in plane ole English: https://grassrootsmotorsports.com/articles/watermethanol-injection-kit-tuning-aid-you-need/

so when I started working with my HP tuner I started paying for these courses I recomment Matt you pay for some lessons because I am sure they will tell you meth is a cooling only non fuel: https://www.hpacademy.com/previous-webinars/069-watermeth-injection-tuning-motec-m150/

I know I know diesel but regardless it still applies and would be great for @SM105K since he asked about it earlier. https://www.mdpi.com/2077-1312/13/5/949

and lastly a more technical read but very informative, after seeing the charts how could you or anyone say just cooling over tuning and making the changes for the PCM to adapt properly....

https://www.researchgate.net/public..._Turbocharged_GDI_Engine_Comparative_Analysis

Matt dude just admit to yourself u do this machination for your own preservation. less time adjusting for each daily driver car you tune for and for your liability in making the wrong adjustments.

we are not talking about the deviation of someone adding gas that has 92 and not 93 octane as an overly simple example. btw for both of you other than cheerleaders most of the main audience in these threads have tuned the fck out.

802 for your argument and I believe your position it would be best to cool off I get why you are angry misinformation like this makes it hard to stay on track and people start believing the non factual argument.

Matt dude, don't know ya but please this is grief posting at this point. the more you post the more you put yourself out for scrutiny and discredits your cache here amoung the tone and mean tons of referals members make to your business. but for all you say 802 sounding crazy, it's because his point is correct and I can see how it's making him crazy in. each post.

seriously enough everyone this is madness

The fact remains is that this narrative that meth is for cooling only has never been said by me. If that is an interperetation for something i've conveyed to customers, it was a misunderstanding. So show me where I have said that meth is for cooling only. And don't confuse AFR with lambda read by an O2 sensor like you just did above. You have to convert that. At the end of the Day, lambda at the exhaust is lambda.

 

[kryptto]

so great say that everything posted about properly requiring tuning to any system using meth in any qty puts this to bed.

 

[kryptto]

The fact remains is that this narrative that meth is for cooling only has never been said by me. If that is an interperetation for something i've conveyed to customers, it was a misunderstanding. So show me where I have said that meth is for cooling only. And don't confuse AFR with lambda read by an O2 sensor like you just did above. You have to convert that. At the end of the Day, lambda at the exhaust is lambda.

you have any fact based research posted here to settle this, if not Matt this is just old and wrong.

 

[mattr66usa]

There’s also an important ethical distinction here.

It’s one thing for an individual to experiment on their own car and accept the consequences while the system adapts imperfectly. It’s another thing entirely to sell that approach to paying customers.

Customers are paying for expertise and intent, not for “let the car sort it out” behavior. Forwarding an untuned fuel and combustion modifier to customers is not a difference in philosophy — it’s a failure to calibrate responsibly.

For the last time the tune accommodates it. And unless you can articulate your points other than they way you think it works, you have no leg to stand on. Unless you can prove to me you understand the fundamentals of this platform, you have no leg to stand on when criticizing my method for tuning them.

 

[mattr66usa]

you have any fact based research posted here to settle this, if not Matt this is just old and wrong.

I fully intend to make it crystal clear in the technical posts because there are some fundamentals that get missed and need to be outlined first. Just humor me and it will be clear to all. By the time we get to topic 4 it will start making sense to everyone.

 

[802SHO]

Nope, not at all.... I'm willing to put it all out there but you have to start with the basic understanding on how these are tuned and you don't possess that knowledge it seems. You can either prove otherwise or learn in the process and I don't care which it is honestly. The problem is you keep saying things that are abstract and have no real application and are saying things that negatively impact my reputation. We can either start at the bottom where you can prove my fundamentals leading up to the way I tune for methanol are flawed, or you can stop saying things that are completely unsubstantiated. Your choice. You have a fork in the road. Which path will you take?

Matt, this isn’t abstract, and it isn’t reputation damage — it’s about professional responsibility.

The H&R spring analogy applies because customers don’t buy parts in isolation, they buy outcomes. When someone installs springs, alignment and damping are part of doing the job correctly. No shop says “the car will figure it out” and walks away — because that would be negligent even if the car seems fine.

Methanol is the same category of modification. It is not cosmetic. It alters combustion speed, effective fuel mass, charge cooling, residual fraction, and modeled load. Whether the engine “handles it” via adaptive logic is not the question. The question is whether the calibration accounts for it intentionally.

This is where integrity matters — doing the right thing when the customer doesn’t know what to ask.

I am not disputing your understanding of MBT as a concept. We agree on MBT theory. Where we diverge is turning MBT and VE observations on a drive-pressure-limited system into hard limits, and then using that to justify not explicitly tuning for methanol under the assumption the PCM will “sort it out.”

That is the specific technical disagreement.
You asked for fundamentals, so here they are clearly stated:

1)Methanol is not “just cooling.” It is additional fuel mass with a different burn characteristic.

2)Any amount of methanol changes combustion dynamics and therefore shifts optimal calibration targets.

Adaptive correction is not the same as intentional tuning.

1. Allowing customers to add methanol without explicit calibration changes is not equivalent to refusing to support methanol — it is implicitly endorsing an untuned configuration.
2. That distinction matters ethically, not emotionally.
3. You say I’m abstract, yet you have not identified a single point above that is technically incorrect — only that you believe it is unnecessary.

So here is the fork, stated plainly and technically:

Either explain why intentionally not tuning for a known combustion modifier is acceptable practice for paying customers, or acknowledge that “the car will adapt” is a compromise, not best practice.

 

[802SHO]

Matt, saying “the tune accommodates it” isn’t a technical explanation unless you define what is being changed and why.

Here are the fundamentals, stated plainly and concretely for this platform:

1)This is a speed-density EcoBoost. Load and inferred airflow are modeled from MAP, IAT, and VE, not directly measured mass airflow.

2)Methanol introduces additional fuel mass and alters combustion characteristics. That necessarily changes effective aircharge, burn rate, and torque response.

3)Adaptive logic and knock control can react to error, but they do not constitute intentional calibration for a known fuel and combustion modifier.

4)If meth is “accommodated,” that means specific calibration elements are adjusted to reflect its presence (fueling targets, spark strategy, torque modeling, safeguards). Otherwise, the system is simply correcting around an unmodeled change.

That’s not “how I think it works” — that’s how this platform works.
So here’s the specific question, staying strictly on fundamentals:

When you say the tune accommodates methanol, what intentional calibration changes account for the added fuel mass and altered combustion behavior, as opposed to relying on adaptive correction?

If you can explain that mechanism, we’re aligned. If not, then “the tune accommodates it” is an assertion, not a demonstrated method.

 

[802SHO]

I’ve never asserted myself as an “expert” but it’s pretty clear who isn’t

 

[mattr66usa]

I’ve never asserted myself as an “expert” but it’s pretty clear who isn’t

You keep saying that I don't tune for meth, but you can't tell me how I should tune for meth. I'm telling you how I accommodate for meth but you can't understand how this works. You won't get out of the abstract because you can't comprehend the technicals.

 

[mattr66usa]

Matt, saying “the tune accommodates it” isn’t a technical explanation unless you define what is being changed and why.

Here are the fundamentals, stated plainly and concretely for this platform:

1)This is a speed-density EcoBoost. Load and inferred airflow are modeled from MAP, IAT, and VE, not directly measured mass airflow.

2)Methanol introduces additional fuel mass and alters combustion characteristics. That necessarily changes effective aircharge, burn rate, and torque response.

3)Adaptive logic and knock control can react to error, but they do not constitute intentional calibration for a known fuel and combustion modifier.

4)If meth is “accommodated,” that means specific calibration elements are adjusted to reflect its presence (fueling targets, spark strategy, torque modeling, safeguards). Otherwise, the system is simply correcting around an unmodeled change.

That’s not “how I think it works” — that’s how this platform works.
So here’s the specific question, staying strictly on fundamentals:

When you say the tune accommodates methanol, what intentional calibration changes account for the added fuel mass and altered combustion behavior, as opposed to relying on adaptive correction?

If you can explain that mechanism, we’re aligned. If not, then “the tune accommodates it” is an assertion, not a demonstrated method.

Again you don't comprehend and are scared to learn the truth.

 

[802SHO]

Again you don't comprehend and are scared to learn the truth.

Bro you are out of data. Point blank. Checkmate

 

[802SHO]

Again you don't comprehend and are scared to learn the truth.

If you believe I’m wrong, identify a specific technical error in my reasoning and explain why it’s incorrect.

Saying “the tune accommodates it” without defining what is changed and how is not a technical answer. Until that happens, there’s nothing further to debate.

 

[mattr66usa]

I have explained it multiple times and I'll show datalogs once you prove you understand even the basics which you have yet to do.... Get in the technical thread 2 so you can prove you don't know even the basics. I'm one for one so far, so I don't know what this checkmate is all about....

 

[mattr66usa]

If you believe I’m wrong, identify a specific technical error in my reasoning and explain why it’s incorrect.

Saying “the tune accommodates it” without defining what is changed and how is not a technical answer. Until that happens, there’s nothing further to debate.

Do you have proof my tune does not? Show me a datalog.

 

[802SHO]

I have explained it multiple times and I'll show datalogs once you prove you understand even the basics which you have yet to do.... Get in the technical thread 2 so you can prove you don't know even the basics. I'm one for one so far, so I don't know what this checkmate is all about....

Matt, you’re asking for datalogs while also saying you won’t share datalogs or technical details unless I “prove I understand the basics.” That isn’t how a technical discussion works.

I’m not claiming I have logs that prove your tune does or doesn’t do anything. I’m claiming you still haven’t provided a technical explanation of what “the tune accommodates it” means in practice, specifically what is being changed and why, when methanol is introduced.

If you want to prove me wrong, identify one specific technical statement I’ve made that is incorrect, and explain why it’s incorrect. Otherwise this has turned into “trust me bro” plus personal attacks, and the conversation ends here.