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Understanding Tuning

1749 Views 11 Replies 5 Participants Last post by  mrvex
Hello,

I've recently listened to the Smoking Tire Podcast with M-Engineering and found it very informative and has raised questions in my mind. I wanted to speak to a community about tuning and what actually happens if I were to send my 720s ECU for a tune. I stumbled across this forum in hopes to better understand what will happen and what the expected outcome will be.

1. Why should I tune my ECU? Is the stock tune not good? Is there something I am missing that I will only find once I unlock the ECU?
2. They spoke about adding in additional safety features. What extra protection will I get over my current 720s features? I feel this is a strong selling point and has me worried about my stock 720s. Or is this mainly if I were to track the car (haven't done to date).
3. With increased performance, will I not run into issues with my engine? I assume power is added through boost pressure?

I hope this is the correct place to post this question. First time posting and this old boy is not that great with technology, however want to learn more as I have an inquisitive mind.
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Happy to help! And thanks for listening! Matt is a great guy.

1) There is not an underlying "need" to tune your ECU. The OEM McLaren calibration is just fine and is plenty for most. However, when the vehicle's speed, power, and sound becomes relative to the driver they often times seek out modifications and a calibration. The end goal of a calibration is to typically increase power output but it can also change the immersiveness of the whole driving experience.

2) The safety features mentioned in the podcast are unique to M-Engineering calibrations. We touch base on the knock safety in this post which may give you a good idea of how they work in general. We also implement engine safeties for fuel pressure, overboost, fuel trims, lambda, clutch slip, and misfires. They work by monitoring engine data and implementing a temporary throttle closure if the data is outside of safe bounds. For instance a knock safety would come in handy if you got a poor tank of gas. The fuel pressure would come in handy if you have an issue with your fuel pump or simply run out of gas during heavy acceleration. A misfire safety would alert you to a possible ignition coil or plug needing maintenance. These safeties are compiled along with OEM code which allows them to always run in the background and take action whenever necessary. It is a passive feature of our calibrations.

3) Typically, engine life is not much of a factor, however with any modification there is always a risk, particularly if you're worried about a factory warranty. We do our best to mitigate chances of failure via engine safeties, calibration experience, and having a very data focused mindset. We are always available to look at data logs which you can take using M-Tuner. However, failures can happen, just like they do with OEM factory setups. We continuously update our calibration with added features and revisions over time. These updates are always free to the original owner of the calibration and are made easy with OBD flashing using the M-Tuner flashing utility and OBD Dongle. M-Tuner is the only at home, flashing device, capable of flashing over OBD. It simply requires a one-time bench unlock. This allows us to remote update calibrations for changes in modifications, diagnostics, or remote dyno tuning. We tune cars remotely daily, In fact, we dyno tuned a 600LT with Cannonball Garage today and we are remote tuning a heavily modified 650S with Motor Lab this evening at 11PM. MotorLab is based out of Moscow and build great cars.

From a broad overview, power is typically generated by increasing boost pressure, changing lambda targets, and modifying ignition timing. In most cases, particularly for pump gas, we end up removing timing from OEM as it is a tad too aggressive for most octane available in the US, especially 91 octane. There does exist means of addition through subtraction when it comes to ignition timing. If you're right on the knock threshold of a fuel and the engine senses detonation it will typically pull between 1.5* to 3.75* based on knock intensity ratio as outlined in the table below. The resolution of the ignition timing table allows you to make adjustments in .75* increments. So if you're right on the cusp of detonation and it pulls timing at 6400RPM or above it will pull 3* of timing. However, If you were to only retard the ignition timing target .75* and the knock ceases you ultimately add 2.25* of timing with more stable combustion. Since McLaren's on pump gas operate far from Maximum Brake Torque (MBT), 2.25* will result in a healthy 25-30whp. This is why we offer calibrations for 91/95RON, 93/98RON, 100/104RON, 104/109RON, E85 and more. It allows us to properly optimize the calibration for the octane without running it too aggressive.

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We are more than happy to help you out with any further questions. We really only touched the tip of the iceberg discussing our engine safeties and OBD flashing as far as our feature set goes. We also have map switching, Rolling Anti-Lag, Read Faults in ECU/PCCU, Clear Faults in all modules, HyperLogging, and many more motorsport focused features like adjustable Launch Control, Custom Traction Control, Burnout Mode, and more.

We try our best to rid the exotic aftermarket of the smoke and mirrors that have surrounded tuning for years. We are an open book, unless it is proprietary, so if you would like to get more into the nitty gritty of tuning we can also go down that path.

Thanks for posting!

M-Engineering
[email protected]
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Hi Bobsfurniture and others who are interested to tune,

I am going to back up what @M-Engineering is saying here, but I think there is a need for more technical info, as to be honest the forum needs it. Phh where to start, so lets get into it. As having a McLaren background and working for the company in the UK, I have seen a few things/lucky enough to learn more than the average having worked with some very experienced people who have been technical support for years on end.

There seems to be a lot of people worried about tuning their McLarens due to "reliability". From experience, I can tell you, these cars yes have their gremlins which most of the time small electrical issues, however, the engines are STRONG if maintained properly and some technical common sense being used, yes there have been some instances of cracked liners and thrown rods, but from the cases I have seen, have mainly been because of poor maintenance, abuse or poor tuning. I think its fair to say that there are some poor tuning techniques out there, which I have seen myself, and having dedicated about a year to learning how to tune this particular platform, great benefits can be found in tuning these cars if done properly.

While the stock mapping as already mentioned is good, there are some negatives within the tuning which could do with some refinement, such areas include the fueling, McLarens run far too rich with a minimum of .67 Lambda on full throttle under certain conditions (Component protection), running fueling so rich, can actually INCREASE EGTs to around 800c, so while this might cool down combustion temperatures the temperature of the exhaust gases is significantly increased putting extra heat into the turbos, manifolds (which is probably why some have cracked P13 upwards), oil, etc is obviously not a good thing, which is why tuners like me, and M-engineering fine tune this area which actually results in much lower EGTs at full load by about 50-60c. (730-740c).

The ECU strategy is mainly operated on requested load and EGT modelling, once a certain EGT is seen by the ECU, (850c) component protection will come in and you will be running .67 lambda. (9.98-10 AFR) or so, this is detrimental for power and of course EGTs, (exhaust gas temperatures). So as I said above, this is an area that is greatly improved to around .79/.80 Lambda with tuning, and from the amount of logging I have done, these cars after a few pulls will kick into component protection mode anyway, and mainly maintain this very rich operating condition. As the too rich lambda will generate the high EGTs and its a never ending cycle from there on in unless you allow the engine to cool for a significant amount of time, so tuners will opt to change this map to keep EGTs under control.

Another area that is optimized is the ignition timing, the profile as stock is as said, aggressive but well controlled knock strategy that will pull timing to protect the engine from any damage, so this isn't a problem, ignition timing is a key factor in making more power, but we have to be safe with it and use the right amount as it will be destructive on any engine.

Boost is another aspect of tuning which is cranked up a little, approx. 18-19 PSI (tuned) depending on the platform but we will use 12c/650 as an example. This is also an area that is closely monitored. The ecu has a MAP sensor limit which needs to be set correctly, once we set this limit, the boost will not exceed, and is there to protect the turbos running too much boost into the engine, if the fueling is good, then the engine can see higher boost levels/timing without any issues, the problem is when intake air temperatures get too high and boost is not limited by poor tuning (example map below), I have had a car come to me with boost vs IAT maps still requesting full load/boost to the engine at temperatures above 90c, which is totally asking for trouble and this is the point we are making here, if the tuning is done correctly, there is really nothing to worry about, I have just tuned my McLaren myself and I am really happy with the results. Its so much better, I am hitting the dyno on Friday and I will post in this thread the before and after dyno results.

Example of stupid and unsafe tuning of a Load vs IAT map.


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My advice to all McLaren owners would be to tune their cars, but, make sure it has been done by someone who knows that they are doing, just as an FYI, tuning these cars do not need to be done by a McLaren expert, they run the same ECU has some Audis and VWs. If someone knows how to tune those well, they can also tune McLaren's well.

To summaries the tuning process it consists of: Raising map limits, fueling, Boost, ignition timing, torque changes, there are various maps within these areas, but this is mainly all that is changed, tuning is like making a 5* meal, with the right amount of ingredients, its fantastic.

The engines can take the tuning if its done properly. Its really nothing to be scared about also regarding the warranty issue, the way this is checked to see if the car is tuned is by using the calibration area (map segment of the data's checksum vs McLarens) once the data within the ecu is changed, the checksum also have to change, McLaren stock calibrations all use the SAME checksum, so its easy for them to check if the data is stock or not, but if you take the car for any warranty work I don't think warranty voiding is an issue if you revert to stock via BENCH flashing and you keep the RPM limit standard, you will be fine and it will in the main go undetected, because if you exceed the RPM limit stock, that will show in diagnostics and its obvious, its pointless changing the RPM limit of these engines anyway as there is little power after 7500 with stock turbos, bigger turbos its obvs another story.

In terms of safeties, the ecu from factory have these anyway (Knock, Fuel trims and some others) but m-engineering have been smart and added more just incase for the sake of people who do not understand what is going on.

Open to any questions so please ask, I hope you found this interesting,

Mike
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Couldn't agree more with your statement below @mrvex. When we retune cars and see this table setup this way it is almost always a dead giveaway that the previous tuner was using a server file and has very little understanding of what they actually put on the car. It seems the "go-to" method of most tuners is to just raise all of the limits out of the way rather than calibrating the various load, torque, pressure, etc... limits to the proper setpoints.

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Couldn't agree more with your statement below @mrvex. When we retune cars and see this table setup this way it is almost always a dead giveaway that the previous tuner was using a server file and has very little understanding of what they actually put on the car. It seems the "go-to" method of most tuners is to just raise all of the limits out of the way rather than calibrating the various load, torque, pressure, etc... limits to the proper setpoints.

View attachment 227688
I would also blame this on the reason why some liners have cracked and rods thrown I literally know of 2 other tuners on the planet who write their own files apart from me, DME, and you guys.

I have also seen the turbo efficiency table totally changed with stock turbos. LOL
Hi Both,

thank you ever so much for taking the time to give me such a detailed response. I read both and had to go away to do a bit of reading. I hope it’s okay to ask for a bit more information regarding your answers. As there is a lot I want to understand, wish I became an engineer, but 52 year old me just doesn’t have the time or patience anymore.

First off Mike, awesome to hear about your experience! Thank you for sharing. Must have been a dream to work everyday in the home of these supercars. Based on your reply sounds like you were quite involved in the engines?

I went through my owners manual and service schedules, but couldn’t find anywhere a mention of a EGT sensor. How is EGT measured?
My first set of questions are around your points of the car running such extreme lambda. Why are they doing that? What is this component protection and what needs protecting?

I would like to touch on the other points that you both raised after the EGT/protection topics. Still researching, but it’s better to hear from the experts


Hi Bobsfurniture and others who are interested to tune,

I am going to back up what @M-Engineering is saying here, but I think there is a need for more technical info, as to be honest the forum needs it. Phh where to start, so lets get into it. As having a McLaren background and working for the company in the UK, I have seen a few things/lucky enough to learn more than the average having worked with some very experienced people who have been technical support for years on end.

There seems to be a lot of people worried about tuning their McLarens due to "reliability". From experience, I can tell you, these cars yes have their gremlins which most of the time small electrical issues, however, the engines are STRONG if maintained properly and some technical common sense being used, yes there have been some instances of cracked liners and thrown rods, but from the cases I have seen, have mainly been because of poor maintenance, abuse or poor tuning. I think its fair to say that there are some poor tuning techniques out there, which I have seen myself, and having dedicated about a year to learning how to tune this particular platform, great benefits can be found in tuning these cars if done properly.

While the stock mapping as already mentioned is good, there are some negatives within the tuning which could do with some refinement, such areas include the fueling, McLarens run far too rich with a minimum of .67 Lambda on full throttle under certain conditions (Component protection), running fueling so rich, can actually INCREASE EGTs to around 800c, so while this might cool down combustion temperatures the temperature of the exhaust gases is significantly increased putting extra heat into the turbos, manifolds (which is probably why some have cracked P13 upwards), oil, etc is obviously not a good thing, which is why tuners like me, and M-engineering fine tune this area which actually results in much lower EGTs at full load by about 50-60c. (730-740c).

The ECU strategy is mainly operated on requested load and EGT modelling, once a certain EGT is seen by the ECU, (850c) component protection will come in and you will be running .67 lambda. (9.98-10 AFR) or so, this is detrimental for power and of course EGTs, (exhaust gas temperatures). So as I said above, this is an area that is greatly improved to around .79/.80 Lambda with tuning, and from the amount of logging I have done, these cars after a few pulls will kick into component protection mode anyway, and mainly maintain this very rich operating condition. As the too rich lambda will generate the high EGTs and its a never ending cycle from there on in unless you allow the engine to cool for a significant amount of time, so tuners will opt to change this map to keep EGTs under control.

Another area that is optimized is the ignition timing, the profile as stock is as said, aggressive but well controlled knock strategy that will pull timing to protect the engine from any damage, so this isn't a problem, ignition timing is a key factor in making more power, but we have to be safe with it and use the right amount as it will be destructive on any engine.

Boost is another aspect of tuning which is cranked up a little, approx. 18-19 PSI (tuned) depending on the platform but we will use 12c/650 as an example. This is also an area that is closely monitored. The ecu has a MAP sensor limit which needs to be set correctly, once we set this limit, the boost will not exceed, and is there to protect the turbos running too much boost into the engine, if the fueling is good, then the engine can see higher boost levels/timing without any issues, the problem is when intake air temperatures get too high and boost is not limited by poor tuning (example map below), I have had a car come to me with boost vs IAT maps still requesting full load/boost to the engine at temperatures above 90c, which is totally asking for trouble and this is the point we are making here, if the tuning is done correctly, there is really nothing to worry about, I have just tuned my McLaren myself and I am really happy with the results. Its so much better, I am hitting the dyno on Friday and I will post in this thread the before and after dyno results.

Example of stupid and unsafe tuning of a Load vs IAT map.


View attachment 227675



My advice to all McLaren owners would be to tune their cars, but, make sure it has been done by someone who knows that they are doing, just as an FYI, tuning these cars do not need to be done by a McLaren expert, they run the same ECU has some Audis and VWs. If someone knows how to tune those well, they can also tune McLaren's well.

To summaries the tuning process it consists of: Raising map limits, fueling, Boost, ignition timing, torque changes, there are various maps within these areas, but this is mainly all that is changed, tuning is like making a 5* meal, with the right amount of ingredients, its fantastic.

The engines can take the tuning if its done properly. Its really nothing to be scared about also regarding the warranty issue, the way this is checked to see if the car is tuned is by using the calibration area (map segment of the data's checksum vs McLarens) once the data within the ecu is changed, the checksum also have to change, McLaren stock calibrations all use the SAME checksum, so its easy for them to check if the data is stock or not, but if you take the car for any warranty work I don't think warranty voiding is an issue if you revert to stock via BENCH flashing and you keep the RPM limit standard, you will be fine and it will in the main go undetected, because if you exceed the RPM limit stock, that will show in diagnostics and its obvious, its pointless changing the RPM limit of these engines anyway as there is little power after 7500 with stock turbos, bigger turbos its obvs another story.

In terms of safeties, the ecu from factory have these anyway (Knock, Fuel trims and some others) but m-engineering have been smart and added more just incase for the sake of people who do not understand what is going on.

Open to any questions so please ask, I hope you found this interesting,

Mike
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Yes it had it perks and it was fun and a lot of horse play, but the monetary side of things wasn't great so decided to move on to something unfortunately more officey which pays better.

Yeah I think you will find this one interesting McLarens dont actually use EGT sensors, they use simulated temperatures based on Lambda, as different lambda values have different temperatures, so based on what lambda is being seen by the ecu, the ecu has a logic built into it that engineers researched using an actual EGT to measure different lambda temperatures. Very good idea actually, it works as it should.

Component protection is what is says on the tin really. Its used to cool down the engine components when things get a bit toasty by throwing fuel in, its not great for the cats though. This also what causes the flames out the back of the car when its been running on track. Its a total waste of fuel to run it that rich and yes other things get even hotter such as the exhaust/ cats and turbos.
Yes it had it perks and it was fun and a lot of horse play, but the monetary side of things wasn't great so decided to move on to something unfortunately more officey which pays better.

Yeah I think you will find this one interesting McLarens dont actually use EGT sensors, they use simulated temperatures based on Lambda, as different lambda values have different temperatures, so based on what lambda is being seen by the ecu, the ecu has a logic built into it that engineers researched using an actual EGT to measure different lambda temperatures. Very good idea actually, it works as it should.

Component protection is what is says on the tin really. Its used to cool down the engine components when things get a bit toasty by throwing fuel in, its not great for the cats though. This also what causes the flames out the back of the car when its been running on track. Its a total waste of fuel to run it that rich and yes other things get even hotter such as the exhaust/ cats and turbos.
Many thanks to all participants. I am a rookie driving a Maclaren 650s spyder Can-Am built in 2016. There are so many opinions about ECU tuning. To me it's very interesting that the engine runs too rich at full throttle. But many experts give warnings of reducing the mixture. Thus I don't what to believe.
The concept of M engineering with the several octane levels switchable by the cruise controller is convincing. In addition here in Germany high octane fuel (ROZ 100-102) is available everywhere. My second question is whether the modifications by M engineering are also suitable and making much gain for my European model which seems to be already optimized for ROZ 98 octane as I read.
Thank you very much in advance.
Best Regards,
Michael from Germany
Hey,

Yes it is way too rich and this is a fact to the level that the car is not that fuel efficient. Take a look at your exhaust after having a hard drive and you will see what I mean. Black. In the world of tuning and engine, every tuner knows the optimal AFR for the engine. For example, most naturally aspirated cars run max power at 12.9-13.0 AFR, McLarens on the other hand around 11.7, most other turbocharged engines also depending on ignition timing mainly and of course a few other things.

McLarens have aggressive timing from factory but the extremely rich mixture at WOT can support that timing but suffers in terms of optimal power because of the slower burn and the unburnt fuel ends up out the back and sticks to the exhaust tips. When tuned, all of the fuel is burnt and the mix burns faster too.

Your car is running what is used by mclaren is “rest of world configuration” meaning its maxed out and optimised for 97 RON. ROW cars consist of middle east, asia and europe. What is known as FED spec is for american cars only and the mapping is slightly different for emissions purposes, but there isnt much difference in power

I hope that clears some things up :)

Any questions pls ask
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Hey,

Yes it is way too rich and this is a fact to the level that the car is not that fuel efficient. Take a look at your exhaust after having a hard drive and you will see what I mean. Black. In the world of tuning and engine, every tuner knows the optimal AFR for the engine. For example, most naturally aspirated cars run max power at 12.9-13.0 AFR, McLarens on the other hand around 11.7, most other turbocharged engines also depending on ignition timing mainly and of course a few other things.

McLarens have aggressive timing from factory but the extremely rich mixture at WOT can support that timing but suffers in terms of optimal power because of the slower burn and the unburnt fuel ends up out the back and sticks to the exhaust tips. When tuned, all of the fuel is burnt and the mix burns faster too.

Your car is running what is used by mclaren is “rest of world configuration” meaning its maxed out and optimised for 97 RON. ROW cars consist of middle east, asia and europe. What is known as FED spec is for american cars only and the mapping is slightly different for emissions purposes, but there isnt much difference in power

I hope that clears some things up :)

Any questions pls ask
Hey,
thank you very much for your fast reply.
Yes, indeed, that helps. But I don't know whether I caught quite all of that.
As my car with "the rest of the world configuration" is optimised for ROZ 97 the gain with a ROZ 100 mapping e.g. from M engineering won't be significant at the top. Am I right?
Thank you
BR Michael
Yeah, most dont understand really, lol thats why tuning is only for the minority. When the car is tuned it will be optimised for whatever you ask for in basic terms.
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