Will a "tune" void your warranty?

[exdeath]

Originally posted by: joutlaw

I think the best option for you if you are afraid of losing your warranty is to buy a spare ECU and get it flashed... I don't know if thats an option because some vehicles have ECU and transmission control modules.

Not always an option or worth the effort with newer cars, as the ECU is tied by serial # with the cluster, transponder, and other components of the car for the passive anti-theft system.

 

[PhoKingGuy]

Originally posted by: exdeath

Originally posted by: Zenmervolt
There's a lot of mis-information in this thread.

Legally, the manufacturer can only refuse to honor a warranty claim if they can prove that the failure was caused by the aftermarket part/tune/etc. Obviously a tune won't void the warranty for the entire car (e.g. things like the oil pump, the water pump, the power windows, the gauges, the ignition system, etc). A dealer may very well give you a hard time about it and you may have to fight with them a little if they find out that you have uploaded a software tune, but unless they can prove that the failure was caused by the software, the manufacturer is not legally allowed to deny warranty coverage.

While an "add-on" type of warranty may be more restrictive, they would still need to prove that the damage was cause by the aftermarket tune and could not deny coverage based on the mere fact that a tune had been uploaded. The extended warranty company will fight more, but you should still win unless the tune was the cause of the failure.

It is extremely unlikely that a tune would be the direct cause of a failure; especially the relatively mild sort of tuning that you're considering. Still, it's likely that a warranty company would give you a hassle over it even though you would prevail in court (again, assuming that the failure was not caused by the tune).

ZV

This.

http://en.wikipedia.org/wiki/Magnuson-Moss_Warranty_Act

If you burn a piston or something, they can link it to the mixture and timing changes caused by the tune. But they can't deny warranty replacement if your oil pump goes out and destroys your engine for reasons unrelated to the tune. The problem has to be proven to be directly caused by the aftermarket product in order to void the warranty. The presence of modifications alone is not sufficient to legally deny warranty coverage.

This maybe true, but a lot of companies are getting around his by monitoring driving habits via ECU. The EVO-X ecu records all instances of heavy throttle use, the VW ECU records everytime the car is red-lined continuously, etc. Though most of these are with cars marketed towards younger people, i've heard instances of dealers pinning the stupidest things on modded cars.

In general, you need to find a dealership that is mod-friendly, then it'll be a lot easier for you

 

[Wuzup101]

Originally posted by: PhoKingGuy

Originally posted by: exdeath

Originally posted by: Zenmervolt
There's a lot of mis-information in this thread.

Legally, the manufacturer can only refuse to honor a warranty claim if they can prove that the failure was caused by the aftermarket part/tune/etc. Obviously a tune won't void the warranty for the entire car (e.g. things like the oil pump, the water pump, the power windows, the gauges, the ignition system, etc). A dealer may very well give you a hard time about it and you may have to fight with them a little if they find out that you have uploaded a software tune, but unless they can prove that the failure was caused by the software, the manufacturer is not legally allowed to deny warranty coverage.

While an "add-on" type of warranty may be more restrictive, they would still need to prove that the damage was cause by the aftermarket tune and could not deny coverage based on the mere fact that a tune had been uploaded. The extended warranty company will fight more, but you should still win unless the tune was the cause of the failure.

It is extremely unlikely that a tune would be the direct cause of a failure; especially the relatively mild sort of tuning that you're considering. Still, it's likely that a warranty company would give you a hassle over it even though you would prevail in court (again, assuming that the failure was not caused by the tune).

ZV

This.

http://en.wikipedia.org/wiki/Magnuson-Moss_Warranty_Act

If you burn a piston or something, they can link it to the mixture and timing changes caused by the tune. But they can't deny warranty replacement if your oil pump goes out and destroys your engine for reasons unrelated to the tune. The problem has to be proven to be directly caused by the aftermarket product in order to void the warranty. The presence of modifications alone is not sufficient to legally deny warranty coverage.

This maybe true, but a lot of companies are getting around his by monitoring driving habits via ECU. The EVO-X ecu records all instances of heavy throttle use, the VW ECU records everytime the car is red-lined continuously, etc. Though most of these are with cars marketed towards younger people, i've heard instances of dealers pinning the stupidest things on modded cars.

In general, you need to find a dealership that is mod-friendly, then it'll be a lot easier for you

I've honestly NEVER head of that on the EVO-X. I did hear some chatter about the GTR ecu logging when launch control was used.... however... I never heard anyone on the evo forums mention anything about the ECU logging. For the record, I do have an X... and I don't have the shitty stock tune lol....

 

[PhoKingGuy]

Originally posted by: Wuzup101

Originally posted by: PhoKingGuy

Originally posted by: exdeath

Originally posted by: Zenmervolt
There's a lot of mis-information in this thread.

Legally, the manufacturer can only refuse to honor a warranty claim if they can prove that the failure was caused by the aftermarket part/tune/etc. Obviously a tune won't void the warranty for the entire car (e.g. things like the oil pump, the water pump, the power windows, the gauges, the ignition system, etc). A dealer may very well give you a hard time about it and you may have to fight with them a little if they find out that you have uploaded a software tune, but unless they can prove that the failure was caused by the software, the manufacturer is not legally allowed to deny warranty coverage.

While an "add-on" type of warranty may be more restrictive, they would still need to prove that the damage was cause by the aftermarket tune and could not deny coverage based on the mere fact that a tune had been uploaded. The extended warranty company will fight more, but you should still win unless the tune was the cause of the failure.

It is extremely unlikely that a tune would be the direct cause of a failure; especially the relatively mild sort of tuning that you're considering. Still, it's likely that a warranty company would give you a hassle over it even though you would prevail in court (again, assuming that the failure was not caused by the tune).

ZV

This.

http://en.wikipedia.org/wiki/Magnuson-Moss_Warranty_Act

If you burn a piston or something, they can link it to the mixture and timing changes caused by the tune. But they can't deny warranty replacement if your oil pump goes out and destroys your engine for reasons unrelated to the tune. The problem has to be proven to be directly caused by the aftermarket product in order to void the warranty. The presence of modifications alone is not sufficient to legally deny warranty coverage.

This maybe true, but a lot of companies are getting around his by monitoring driving habits via ECU. The EVO-X ecu records all instances of heavy throttle use, the VW ECU records everytime the car is red-lined continuously, etc. Though most of these are with cars marketed towards younger people, i've heard instances of dealers pinning the stupidest things on modded cars.

In general, you need to find a dealership that is mod-friendly, then it'll be a lot easier for you

I've honestly NEVER head of that on the EVO-X. I did hear some chatter about the GTR ecu logging when launch control was used.... however... I never heard anyone on the evo forums mention anything about the ECU logging. For the record, I do have an X... and I don't have the shitty stock tune lol....

I heard it from a friend of mine whose a master mechanic at VW. Mitsu is fairly draconian with evo warranty claims anyway. I remember a friend of mine getting his warranty canceled for putting an aftermarket clutch in after about 15k miles

 

[rdp6]

PhoKingGuy, have you had your GTI tuned? I had the APR Stage 1 (93 octane) test flash done at Mid Ohio this summer. Made the Passat an absolute animal. I'm waiting until we have a backup car before I have the Passat flashed.

 

[PhoKingGuy]

Originally posted by: rdp6
PhoKingGuy, have you had your GTI tuned? I had the APR Stage 1 (93 octane) test flash done at Mid Ohio this summer. Made the Passat an absolute animal. I'm waiting until we have a backup car before I have the Passat flashed.

Yup, APR stage 1 91 octane (all we get in socal 🙁) Its a complete animal now and they didn't say anything about it when I had my DSG serviced. I love it, plus my mileage didn't change at all.

 

[Jeff7181]

Originally posted by: Ronstang

Originally posted by: Jeff7181

Originally posted by: PhoKingGuy

Originally posted by: ChaosDivine
I know people who use SCT X3s on their Lincoln LSs. Greatly improves the throttle response on the 2nd gens and they just reflash it back to stock before taking it in for servicing.

This, with the VW 2.0T tunes you can simply deactivate the tune and return the car to stock before servicing. Its stealth so the dealer cant tell unless they examine the ECU source code, which they generally dont do.

They may if you come in for warranty work with burnt pistons or other deep engine problems. I think that's the point in asking if these type of mods voids warranties... he wants to know if it blows up is it still covered under warranty and the short answer is no.

I seriously doubt you are going to blow up an engine due to one of these prepackaged tunes. There is a lot of room for tuning and still remaining safe because the manufacturers' tunes are extremely conservative.

You underestimate how delicate an engine actually is. Making more power isn't what's going to hurt the engine... running improper air fuel ratios and timing will.

 

[CurseTheSky]

Originally posted by: Jeff7181

Originally posted by: Ronstang

Originally posted by: Jeff7181

Originally posted by: PhoKingGuy

Originally posted by: ChaosDivine
I know people who use SCT X3s on their Lincoln LSs. Greatly improves the throttle response on the 2nd gens and they just reflash it back to stock before taking it in for servicing.

This, with the VW 2.0T tunes you can simply deactivate the tune and return the car to stock before servicing. Its stealth so the dealer cant tell unless they examine the ECU source code, which they generally dont do.

They may if you come in for warranty work with burnt pistons or other deep engine problems. I think that's the point in asking if these type of mods voids warranties... he wants to know if it blows up is it still covered under warranty and the short answer is no.

I seriously doubt you are going to blow up an engine due to one of these prepackaged tunes. There is a lot of room for tuning and still remaining safe because the manufacturers' tunes are extremely conservative.

You underestimate how delicate an engine actually is. Making more power isn't what's going to hurt the engine... running improper air fuel ratios and timing will.

I think what he's alluding to is that the tunes that come with the Xcalibrator 3 and similar tools are still conservative compared to getting a dyno session + tune. They do lean the mixture out, but it shouldn't be enough to cause immediate damage; no one would buy these things if there were dozens of "my engine blew!" reports floating around the 'net. I did read that the tool gives users the ability to manually set spark advance, shift points, etc. That is something that I wouldn't play around with myself.

Whether or not it causes more wear and tear on the engine over a long period of time is the big question, and unfortunately there are far too many variables involved (and too few people with the time and patience to test it) to get conclusive results.

 

[Jeff7181]

Originally posted by: CurseTheSky

Originally posted by: Jeff7181

Originally posted by: Ronstang

Originally posted by: Jeff7181

Originally posted by: PhoKingGuy

Originally posted by: ChaosDivine
I know people who use SCT X3s on their Lincoln LSs. Greatly improves the throttle response on the 2nd gens and they just reflash it back to stock before taking it in for servicing.

This, with the VW 2.0T tunes you can simply deactivate the tune and return the car to stock before servicing. Its stealth so the dealer cant tell unless they examine the ECU source code, which they generally dont do.

They may if you come in for warranty work with burnt pistons or other deep engine problems. I think that's the point in asking if these type of mods voids warranties... he wants to know if it blows up is it still covered under warranty and the short answer is no.

I seriously doubt you are going to blow up an engine due to one of these prepackaged tunes. There is a lot of room for tuning and still remaining safe because the manufacturers' tunes are extremely conservative.

You underestimate how delicate an engine actually is. Making more power isn't what's going to hurt the engine... running improper air fuel ratios and timing will.

I think what he's alluding to is that the tunes that come with the Xcalibrator 3 and similar tools are still conservative compared to getting a dyno session + tune. They do lean the mixture out, but it shouldn't be enough to cause immediate damage; no one would buy these things if there were dozens of "my engine blew!" reports floating around the 'net. I did read that the tool gives users the ability to manually set spark advance, shift points, etc. That is something that I wouldn't play around with myself.

Whether or not it causes more wear and tear on the engine over a long period of time is the big question, and unfortunately there are far too many variables involved (and too few people with the time and patience to test it) to get conclusive results.

Some people aren't that smart. It's quite possible to damage an engine messing around with this stuff and saying "omg it feels faster!" and leaving it at an unsafe setting.

 

[exdeath]

Originally posted by: PhoKingGuy

Originally posted by: exdeath

Originally posted by: Zenmervolt
There's a lot of mis-information in this thread.

Legally, the manufacturer can only refuse to honor a warranty claim if they can prove that the failure was caused by the aftermarket part/tune/etc. Obviously a tune won't void the warranty for the entire car (e.g. things like the oil pump, the water pump, the power windows, the gauges, the ignition system, etc). A dealer may very well give you a hard time about it and you may have to fight with them a little if they find out that you have uploaded a software tune, but unless they can prove that the failure was caused by the software, the manufacturer is not legally allowed to deny warranty coverage.

While an "add-on" type of warranty may be more restrictive, they would still need to prove that the damage was cause by the aftermarket tune and could not deny coverage based on the mere fact that a tune had been uploaded. The extended warranty company will fight more, but you should still win unless the tune was the cause of the failure.

It is extremely unlikely that a tune would be the direct cause of a failure; especially the relatively mild sort of tuning that you're considering. Still, it's likely that a warranty company would give you a hassle over it even though you would prevail in court (again, assuming that the failure was not caused by the tune).

ZV

This.

http://en.wikipedia.org/wiki/Magnuson-Moss_Warranty_Act

If you burn a piston or something, they can link it to the mixture and timing changes caused by the tune. But they can't deny warranty replacement if your oil pump goes out and destroys your engine for reasons unrelated to the tune. The problem has to be proven to be directly caused by the aftermarket product in order to void the warranty. The presence of modifications alone is not sufficient to legally deny warranty coverage.

This maybe true, but a lot of companies are getting around his by monitoring driving habits via ECU. The EVO-X ecu records all instances of heavy throttle use, the VW ECU records everytime the car is red-lined continuously, etc. Though most of these are with cars marketed towards younger people, i've heard instances of dealers pinning the stupidest things on modded cars.

In general, you need to find a dealership that is mod-friendly, then it'll be a lot easier for you

Those cars have factory rev limiters. If the car allows you to go that high in stock trim, they cannot refuse service for driving the car they way it was meant to be driven. A sports car should be built to handle the rigors of that kind of driving. Nissan learned that the hard way.

 

[exdeath]

Originally posted by: Jeff7181

Originally posted by: CurseTheSky
Whether or not it causes more wear and tear on the engine over a long period of time is the big question, and unfortunately there are far too many variables involved (and too few people with the time and patience to test it) to get conclusive results.

Some people aren't that smart. It's quite possible to damage an engine messing around with this stuff and saying "omg it feels faster!" and leaving it at an unsafe setting.

Or people tuning their cars faster then cheaping out and saving money with 87 octane or not leaving anything on the table for summer time.

 

[exdeath]

Originally posted by: CurseTheSky
Whether or not it causes more wear and tear on the engine over a long period of time is the big question, and unfortunately there are far too many variables involved (and too few people with the time and patience to test it) to get conclusive results.

You could argue that there is less wear and tear. Many factory tunes are extremely conservative and rich. Some Toyotas in particular have a 8-9:1 AFR wide open. Taking some fuel out not only improves fuel economy and increases power, but results in less bore wash (excessive fuel rinsing the oil film off the cylinder walls), longer catalyst life, improved emissions, etc.

It's a result of making one car for every part of the world and tuning for worse case scenarios that 99% of people won't experience.

 

[Zenmervolt]

Originally posted by: PhoKingGuy
I heard it from a friend of mine whose a master mechanic at VW. Mitsu is fairly draconian with evo warranty claims anyway. I remember a friend of mine getting his warranty canceled for putting an aftermarket clutch in after about 15k miles

There are two options:

1) Your friend is lying. It is simply not legal in any way, shape, or form to void an entire warranty for merely installing an aftermarket clutch. The clutch is a wear item anyway that is typically not covered under the usual vehicle warranty (much as brake pads are not covered).

2) Mitsubishi voided your friend's warranty because he was racing the car on a track and cited the aftermarket clutch as evidence of this non-standard use. If the warranty was actually voided, then this is the likely scenario. Pretty much every single automotive warranty will be voided if one races the car, even in something like autocross. You take a car out for a track day and you've voided the warranty. Anyone with half a brain should know this.

There are only two reasons to install an aftermarket clutch: to handle more power from engine mods or because the previous clutch has worn out. Now, if the engine was making enough additional power that the stock clutch couldn't handle it, then there were significant additional modifications besides the clutch and if the original clutch wore out after only 15,000 miles it's very clear that the car was being abused rather heavily. Either way, I guarantee that it wasn't the aftermarket clutch alone in isolation that caused your friend's warranty claim to be denied.

ZV

 

[Jeff7181]

Originally posted by: exdeath

Originally posted by: CurseTheSky
Whether or not it causes more wear and tear on the engine over a long period of time is the big question, and unfortunately there are far too many variables involved (and too few people with the time and patience to test it) to get conclusive results.

You could argue that there is less wear and tear. Many factory tunes are extremely conservative and rich. Some Toyotas in particular have a 8-9:1 AFR wide open. Taking some fuel out not only improves fuel economy and increases power, but results in less bore wash (excessive fuel rinsing the oil film off the cylinder walls), longer catalyst life, improved emissions, etc.

It's a result of making one car for every part of the world and tuning for worse case scenarios that 99% of people won't experience.

Ummm, at WOT don't they run in open loop on a predefined fuel map ignoring sensor feedback? How much time do you spend at WOT? So... why bother optimizing a fuel map for an individual vehicle condition that the vehicle won't see 99% of the time? Makes a little more sense to provide one map for that 1% condition that's safe for all vehicles.

 

[exdeath]

Originally posted by: Jeff7181

Originally posted by: exdeath

Originally posted by: CurseTheSky
Whether or not it causes more wear and tear on the engine over a long period of time is the big question, and unfortunately there are far too many variables involved (and too few people with the time and patience to test it) to get conclusive results.

You could argue that there is less wear and tear. Many factory tunes are extremely conservative and rich. Some Toyotas in particular have a 8-9:1 AFR wide open. Taking some fuel out not only improves fuel economy and increases power, but results in less bore wash (excessive fuel rinsing the oil film off the cylinder walls), longer catalyst life, improved emissions, etc.

It's a result of making one car for every part of the world and tuning for worse case scenarios that 99% of people won't experience.

Ummm, at WOT don't they run in open loop on a predefined fuel map ignoring sensor feedback? How much time do you spend at WOT? So... why bother optimizing a fuel map for an individual vehicle condition that the vehicle won't see 99% of the time? Makes a little more sense to provide one map for that 1% condition that's safe for all vehicles.

The fuel maps are still used in closed loop. The fuel map sets a desired ratio or base injector pulse, and the O2 feedback is used to achieve that set ratio and to calculate global trim necessary to reach it. In a properly tuned and perfect system, the fuel trim would be 0% while the O2 reads the the same value as specified in the table (actual lambda = desired lambda as per fuel map). The difference in open loop is the O2 is ignored, and the pre-learned global trim is simply unconditionally added to the fuel map; there is no real time correction if it happens to be off from the desired ratio as specified in the base fuel map.

The only map that comes into play during WOT only is the accelerator pump shot on on throttle tip in, which is entirely different; it is a momentary spike and does not contribute to the sustained AFR during the full course of sustained acceleration.

It's the default values in the base fuel map that matter. They are extremely conservative and overly safe from the factory more often than not. I'd argue that 8-9:1 AFR is too much, even trying to play it safe, and would cause excessive bore wash and plug fouling. But the car has to be made to protect the manufacturer from being sued by that one guy who puts mud in his gas tank and hauls a trailer up hill in 130 deg weather who can tell everyone how bullet proof Toyotas are instead of melting a piston. The rest of us are safe getting +15 HP and +2 MPG with a tuner or SAFC.

In a car with only 100 HP that barely gets out of it's own way, you make use of the upper reaches of those tables more often than you realize, esp the high load low RPM sections where the factory maps are pig rich.

 

[Jeff7181]

Originally posted by: exdeath

Originally posted by: Jeff7181

Originally posted by: exdeath

Originally posted by: CurseTheSky
Whether or not it causes more wear and tear on the engine over a long period of time is the big question, and unfortunately there are far too many variables involved (and too few people with the time and patience to test it) to get conclusive results.

You could argue that there is less wear and tear. Many factory tunes are extremely conservative and rich. Some Toyotas in particular have a 8-9:1 AFR wide open. Taking some fuel out not only improves fuel economy and increases power, but results in less bore wash (excessive fuel rinsing the oil film off the cylinder walls), longer catalyst life, improved emissions, etc.

It's a result of making one car for every part of the world and tuning for worse case scenarios that 99% of people won't experience.

Ummm, at WOT don't they run in open loop on a predefined fuel map ignoring sensor feedback? How much time do you spend at WOT? So... why bother optimizing a fuel map for an individual vehicle condition that the vehicle won't see 99% of the time? Makes a little more sense to provide one map for that 1% condition that's safe for all vehicles.

The fuel maps are still used in closed loop. The fuel map sets a desired ratio or base injector pulse, and the O2 feedback is used to achieve that set ratio and to calculate global trim necessary to reach it. In a properly tuned and perfect system, the fuel trim would be 0% while the O2 reads the the same value as specified in the table (actual lambda = desired lambda as per fuel map). The difference in open loop is the O2 is ignored, and the pre-learned global trim is simply unconditionally added to the fuel map; there is no real time correction if it happens to be off from the desired ratio as specified in the base fuel map.

The only map that comes into play during WOT only is the accelerator pump shot on on throttle tip in, which is entirely different; it is a momentary spike and does not contribute to the sustained AFR during the full course of sustained acceleration.

It's the default values in the base fuel map that matter. They are extremely conservative and overly safe from the factory more often than not. I'd argue that 8-9:1 AFR is too much, even trying to play it safe, and would cause excessive bore wash and plug fouling. But the car has to be made to protect the manufacturer from being sued by that one guy who puts mud in his gas tank and hauls a trailer up hill in 130 deg weather who can tell everyone how bullet proof Toyotas are instead of melting a piston. The rest of us are safe getting +15 HP and +2 MPG with a tuner or SAFC.

In a car with only 100 HP that barely gets out of it's own way, you make use of the upper reaches of those tables more often than you realize.

I think I see what you're trying to say. The fuel map is a target air/fuel ratio. In closed loop the ECU is using sensor inputs to adjust air/fuel ratio to meet that goal. In open loop it doesn't care about air/fuel ratio and just dumps in a predetermined amount of fuel per throttle position and engine speed (and maybe engine temp?).

So you're saying that target air/fuel ratio based on the base fuel map for certain conditions, like 80-90% throttle is too rich and actually causing a loss of power and excessive fuel so that every engine they produce won't grenade if shitty fuel is used.

I can't help thinking modern engines don't work this way. I swear 8-9 years ago in college ECU's were capable of determining that what the fuel map says is the optimum air/fuel ratio is not always valid under every condition and can modify it from that based on sensor inputs. For example, when cruising down the highway the fuel map might say 15:1 is an appropriate air:fuel ratio... but the computer may look at sensor inputs and adjust it to 16:1 or 17:1. Or at 75% throttle the fuel map may say 10:1 is appropriate but the computer may determine that 12:1 works just fine.

I guess it all depends on the logic the computer is programmed with, but as I said, I'm pretty sure computers had this type of logic 10 years ago.

 

[exdeath]

Originally posted by: Jeff7181

Originally posted by: exdeath

Originally posted by: Jeff7181

Originally posted by: exdeath

Originally posted by: CurseTheSky
Whether or not it causes more wear and tear on the engine over a long period of time is the big question, and unfortunately there are far too many variables involved (and too few people with the time and patience to test it) to get conclusive results.

You could argue that there is less wear and tear. Many factory tunes are extremely conservative and rich. Some Toyotas in particular have a 8-9:1 AFR wide open. Taking some fuel out not only improves fuel economy and increases power, but results in less bore wash (excessive fuel rinsing the oil film off the cylinder walls), longer catalyst life, improved emissions, etc.

It's a result of making one car for every part of the world and tuning for worse case scenarios that 99% of people won't experience.

Ummm, at WOT don't they run in open loop on a predefined fuel map ignoring sensor feedback? How much time do you spend at WOT? So... why bother optimizing a fuel map for an individual vehicle condition that the vehicle won't see 99% of the time? Makes a little more sense to provide one map for that 1% condition that's safe for all vehicles.

The fuel maps are still used in closed loop. The fuel map sets a desired ratio or base injector pulse, and the O2 feedback is used to achieve that set ratio and to calculate global trim necessary to reach it. In a properly tuned and perfect system, the fuel trim would be 0% while the O2 reads the the same value as specified in the table (actual lambda = desired lambda as per fuel map). The difference in open loop is the O2 is ignored, and the pre-learned global trim is simply unconditionally added to the fuel map; there is no real time correction if it happens to be off from the desired ratio as specified in the base fuel map.

The only map that comes into play during WOT only is the accelerator pump shot on on throttle tip in, which is entirely different; it is a momentary spike and does not contribute to the sustained AFR during the full course of sustained acceleration.

It's the default values in the base fuel map that matter. They are extremely conservative and overly safe from the factory more often than not. I'd argue that 8-9:1 AFR is too much, even trying to play it safe, and would cause excessive bore wash and plug fouling. But the car has to be made to protect the manufacturer from being sued by that one guy who puts mud in his gas tank and hauls a trailer up hill in 130 deg weather who can tell everyone how bullet proof Toyotas are instead of melting a piston. The rest of us are safe getting +15 HP and +2 MPG with a tuner or SAFC.

In a car with only 100 HP that barely gets out of it's own way, you make use of the upper reaches of those tables more often than you realize.

I think I see what you're trying to say. The fuel map is a target air/fuel ratio. In closed loop the ECU is using sensor inputs to adjust air/fuel ratio to meet that goal. In open loop it doesn't care about air/fuel ratio and just dumps in a predetermined amount of fuel per throttle position and engine speed (and maybe engine temp?).

So you're saying that target air/fuel ratio based on the base fuel map for certain conditions, like 80-90% throttle is too rich and actually causing a loss of power and excessive fuel so that every engine they produce won't grenade if shitty fuel is used.

I can't help thinking modern engines don't work this way. I swear 8-9 years ago in college ECU's were capable of determining that what the fuel map says is the optimum air/fuel ratio is not always valid under every condition and can modify it from that based on sensor inputs. For example, when cruising down the highway the fuel map might say 15:1 is an appropriate air:fuel ratio... but the computer may look at sensor inputs and adjust it to 16:1 or 17:1. Or at 75% throttle the fuel map may say 10:1 is appropriate but the computer may determine that 12:1 works just fine.

I guess it all depends on the logic the computer is programmed with, but as I said, I'm pretty sure computers had this type of logic 10 years ago.

There are global multipliers and scaling tables for things like coolant temp, battery voltage, etc, that are always modifying the ratio from whats in the base map based on external conditions like weather and wear and tear, that's why it's called a base map. But for the most part the computer is designed to do what it is told to do (follow the fuel map programmed into it) and uses feedback for that purpose. It won't just decide on it's own to ignore your fuel map and do what it thinks it's better. Computers don't think.

The process is generally: compute load and RPM, lookup base map fueling, combined with modifier or offsets for things like coolant temp to come up with a final number, to which a correction trim which defaults to 0 is added. All the O2 sensor adjusts in the fueling equation is the trim correction, which is just that, trim. The majority of the number comes from the base map, even in closed loop. You can tell it to run 18:1 at 80% load at 1500 RPM in the base map and it will happily oblige. It might be running at 17:1 if it's in cold warmup mode or something, set your cold start enrichment to 0, problem solved. It's going to do it's best to attain what you tell it to.

There is really not a "optimum" AFR as far as the computer is concerned. 11:1 might be optimal but you personally might want to make it 12:1 or 10:1 for some mechanical reason the computer isn't aware of. Optimal is whatever you tell it in the base map, it doesn't know nor care. Computers don't think. And even then, what is optimal? Performance? Fuel economy? Catalyst efficiency? Engine temperature and longevity? The computer doesn't decide what is most important, we do, and balancing all those subjective factors and coming up with a base map is what tuning is all about. If you told it to run 10:1 and the computer is running 12:1 it's because we told it to also globally subtract 20% fuel in response to some other signal.

Computers haven't changed much in their fundamental purpose. Just more accurate, more channels, more things to do. eg: Sequential injection instead of batch firing = more injectors to control, COP ignition = built in ignition controller with 4-8 ignition signals from the ECU terminal instead of a single IGT going to a module, higher resolution sensors, faster capture and response times, throttle by wire, single computer fast enough to also handle auto trans without an external trans ECU, high speed data logging and onboard diagnostics, higher memory capacities, higher res tables with less interpolation, anti theft, etc. And even then the most modern engine computers are still a joke (20 Mhz cpus with 4MB RAM is considered extremely powerful in automotive terms). http://en.wikipedia.org/wiki/Intel_8061

 

[Jeff7181]

Of course computers can't think, but they can be programmed with logic and decision making abilities based on conditions and feedback. If what you say is right, and they still aren't designed in such a way, that's a huge failing in my opinion. Seems to me they could add a couple sensors and give the computer more advanced logic to keep the engine running at higher efficiency. By the way... "optimal" is providing the power the driver asks for with their right foot with the minimum amount of fuel without damaging the engine and maintaining emissions standards. It shouldn't be that difficult to monitor this stuff in real time and let the computer adjust for it since we can tune engines on a dyno.

 

[elbobbo]

To be honest, the best way to check these is to hit up your local dealer service dept.

Alot of these guys will honor warranties despite mods because they want the shop to be allotted the essential man-hours and service #s.

Every car I have owned has been modified. Alot of your tuner market cars often install parts for you at the dealership, because many of their mechanics are tuners themselves. You need to shop around.

A local Subaru dealership replaced the transmission on a friends WRX under warranty. The car has a full TBE, upgraded turbo/intercooler, variable boost, new ECU, aftermarket clutch and lightweight flywheel. Every item on that list would void your warranty, but they were cool about it and swapped in not only one, but two transmissions within a 2 year period.

 

[exdeath]

Originally posted by: Jeff7181
Of course computers can't think, but they can be programmed with logic and decision making abilities based on conditions and feedback. If what you say is right, and they still aren't designed in such a way, that's a huge failing in my opinion. Seems to me they could add a couple sensors and give the computer more advanced logic to keep the engine running at higher efficiency. By the way... "optimal" is providing the power the driver asks for with their right foot with the minimum amount of fuel without damaging the engine and maintaining emissions standards. It shouldn't be that difficult to monitor this stuff in real time and let the computer adjust for it since we can tune engines on a dyno.

With some overhead for manufacturing tolerances, environmental and fuel quality differences world wide, meeting the most stringent emissions requirements for a global platform that don't apply in other regions, etc.

We can FINE tune engines on a dyno because it is under the subjective scrutiny of a human overseeing the tuning process on a car by car basis. Auto manufacturers do not have this luxury and are not going to bin and grade and sell cars with multiple horsepower ratings the way Intel sells CPUs. Actually, factory tunes are the result of hundreds of dyno hours and research for a tune suitable to unsupervised running in millions of of the same engine. There is no need for an onboard AI.

No two cars are alike, even sequential VINs right from the factory. Hence a baseline lowest common denominator tune with some padding for safety, variance, and margin of error designed to run for a million miles on a mass produced assembly line. Cars don't leave the factory within 2 degrees of pinging on 91 octane in Washington so they can be driven on 87 octane in Arizona and result in bad PR and warranty issues.

The computers in EFI systems are damn near perfect; they do exactly what we tell them to do, and that is all they need to do. There is no need for AI which would still not replace an experienced human tuner on a case by case dyno session.