[QUOTE="russc"]Theres never a point at which the engine is running outside the FI systems parameters. You never HAVE to listen to the engine, because it's never predetonates. [/QUOTE]
BS. Intercooler heatsoaks, outside air temps get wicked high, you put too much timing in, run too much boost for conditions . . . any or all of those together will create preignition (I'm not exactly sure what predetonation is, is that the sound it makes before it detonates?). Even a fancy wideband controlled FI system running closed loop at a certified 12:1 AFR will not guarantee detonation free running at all times, you still need to listen.
Jeremy
Why squirt? - Resurrected!
[QUOTE="papajetta"]megasuirt does have capabilities to run full time closed loop, and use a wide band sensor as feedback,
so u can basically tell it to run 12:1 air/fuel ratio after a certain MAP reading , or RPM reading
this is the real advantage.[/QUOTE]
Ok, if it can, thats good. Although that is tough to find by their website..
RussC
so u can basically tell it to run 12:1 air/fuel ratio after a certain MAP reading , or RPM reading
this is the real advantage.[/QUOTE]
Ok, if it can, thats good. Although that is tough to find by their website..
RussC
[QUOTE="russc"]Theres never a point at which the engine is running outside the FI systems parameters. You never HAVE to listen to the engine, because it's never predetonates. [/QUOTE]
[QUOTE="Jeremy"]BS. Intercooler heatsoaks, outside air temps get wicked high, you put too much timing in, run too much boost for conditions . . . any or all of those together will create preignition (I'm not exactly sure what predetonation is, is that the sound it makes before it detonates?). Even a fancy wideband controlled FI system running closed loop at a certified 12:1 AFR will not guarantee detonation free running at all times, you still need to listen.
Jeremy[/QUOTE]
I guess I need to be more clear, as in "crystal" :p
If the system is properly designed, all those conditions are accounted for in the FI system. No matter how hot/cold the system is. That way there is no condition the FI can't adjust for. Thats how modern FI systems run. Thats the point. Modern FI systems, especially with forced induction, use temp readings at intake and manifold, pressure, fuel pressure, knock input, coolant temp, O2 ect to adjust timing and fuel delivery. If any of these parameters are way beyond certain limits, the system goes into shut down, limp mode, fuel cut, whatever. The E28 motronics does some this already. Thats why car manufactures test cars in every exteme enviroment so the system knows where all the limits are and runs closed loop, giving better fuel economy and power everywhere.
Now, I know that the E28 can't do all this as the FI computer is primative by todays standards. Most people just tune the car rich and that covers 90% of the conditions the car sees. But that robs power and milage.
Again, if Im going to all the trouble to put a new FI system in the car, I want it all, I want it to work like a modern system will all the bells and whistles. As I've always heard it, "it's nothing money wont solve". If MS can run closed loop, I'm way more interested in it and it's capabilities.
OH, detonation:
Detonation (also called "spark knock") is an erratic form of combustion that can cause head gasket failure as well as other engine damage. Detonation occurs when excessive heat and pressure in the combustion chamber cause the air/fuel mixture to autoignite. This produces multiple flame fronts within the combustion chamber instead of a single flame kernel. When these multiple flames collide, they do so with explosive force that produces a sudden rise in cylinder pressure accompanied by a sharp metallic pinging or knocking noise. The hammer-like shock waves created by detonation subject the head gasket, piston, rings, spark plug and rod bearings to severe overloading.
Ive heard it reffered to as predetonation, that might be my bad (@)
RussC
[Edit by russc on [TIME]1118385367[/TIME]]
[QUOTE="Jeremy"]BS. Intercooler heatsoaks, outside air temps get wicked high, you put too much timing in, run too much boost for conditions . . . any or all of those together will create preignition (I'm not exactly sure what predetonation is, is that the sound it makes before it detonates?). Even a fancy wideband controlled FI system running closed loop at a certified 12:1 AFR will not guarantee detonation free running at all times, you still need to listen.
Jeremy[/QUOTE]
I guess I need to be more clear, as in "crystal" :p
If the system is properly designed, all those conditions are accounted for in the FI system. No matter how hot/cold the system is. That way there is no condition the FI can't adjust for. Thats how modern FI systems run. Thats the point. Modern FI systems, especially with forced induction, use temp readings at intake and manifold, pressure, fuel pressure, knock input, coolant temp, O2 ect to adjust timing and fuel delivery. If any of these parameters are way beyond certain limits, the system goes into shut down, limp mode, fuel cut, whatever. The E28 motronics does some this already. Thats why car manufactures test cars in every exteme enviroment so the system knows where all the limits are and runs closed loop, giving better fuel economy and power everywhere.
Now, I know that the E28 can't do all this as the FI computer is primative by todays standards. Most people just tune the car rich and that covers 90% of the conditions the car sees. But that robs power and milage.
Again, if Im going to all the trouble to put a new FI system in the car, I want it all, I want it to work like a modern system will all the bells and whistles. As I've always heard it, "it's nothing money wont solve". If MS can run closed loop, I'm way more interested in it and it's capabilities.
OH, detonation:
Detonation (also called "spark knock") is an erratic form of combustion that can cause head gasket failure as well as other engine damage. Detonation occurs when excessive heat and pressure in the combustion chamber cause the air/fuel mixture to autoignite. This produces multiple flame fronts within the combustion chamber instead of a single flame kernel. When these multiple flames collide, they do so with explosive force that produces a sudden rise in cylinder pressure accompanied by a sharp metallic pinging or knocking noise. The hammer-like shock waves created by detonation subject the head gasket, piston, rings, spark plug and rod bearings to severe overloading.
Ive heard it reffered to as predetonation, that might be my bad (@)
RussC
[Edit by russc on [TIME]1118385367[/TIME]]
I am totally with Russ in the above statement. Thats why I run CLOSED LOOP at all times with the TEC3 with wide band O2. I have the WB O2 set to 20% adjustment of A/F to keep the A/F where I want it. Once the TEC3 is properly tuned, 10% is all that will be needed. BTW, the WB O2 input can go up to 50% adjustment.
The moronic is a TRS-80, Megasquirt - 486 :p and the TEC3 is a pentium M. Why is that so hard to understand?
[Edit by Duke M535Ti on [TIME]1118386025[/TIME]]
The moronic is a TRS-80, Megasquirt - 486 :p and the TEC3 is a pentium M. Why is that so hard to understand?
[Edit by Duke M535Ti on [TIME]1118386025[/TIME]]
for megasuirt u have to download megasquirt 'n' spark software
that has the additional features for full time closed loop operation, also adds 12x12 ve tables, 12x12 spark tables, 8x8 AFR target tables, boost control, knock sensing, injector staging, .....
i think for the price u just cant beat it,
and makes motronic 1.1 and 1.3 look suitable for a lawn mower.
i mean: no knock sensing, ? what the hell were they thinking ? 40g's for a car ( back then ) and they cant even add a stupid knock sensor?
that has the additional features for full time closed loop operation, also adds 12x12 ve tables, 12x12 spark tables, 8x8 AFR target tables, boost control, knock sensing, injector staging, .....
i think for the price u just cant beat it,
and makes motronic 1.1 and 1.3 look suitable for a lawn mower.
i mean: no knock sensing, ? what the hell were they thinking ? 40g's for a car ( back then ) and they cant even add a stupid knock sensor?
I suspect they didn't add a knock sensor because knock sensors even to this day are highly problematic devices. I have an 88 vintage german vehicle with a knock sensor and its a PITA. I'm thrilled BMW didn't use them.
Read the Jacobs ignition book sometime. Once you train a human to listen for knock, they found that a human can manage ignitition advance better than any of the computer systems they tested.
Read the Jacobs ignition book sometime. Once you train a human to listen for knock, they found that a human can manage ignitition advance better than any of the computer systems they tested.
[QUOTE="FirstFives Dictator"]I guess what I'm saying is I don't care about closed loop except under steady state to keep a cat working.
There are times when I don't want it. Still think the processor between my ears will make better tuning decisions than a 8 bit processor. The MS fuel calculations are the same that many OEM's use, so it's repeatable. You tune it correctly and it stays tuned.
I'm not debating quality of MS product as much as a tuning strategy. Closed loop under boost or WOT is not necessary, IMO.[/QUOTE]
[QUOTE="russc"]My only point would be that a properly running system can run closed loop better than a open loop system. Thats because every varible has been taken into consideration, ALL operating conditions. Theres never a point at which the engine is running outside the FI systems parameters. You never HAVE to listen to the engine, because it's never predetonates. That in itself is a better system, as is in all modern forced induction cars like Mitsu Evo's, Subi's STI's, Benz's SC system, Dodges SRTs ect etc....
While some modern NA cars may still run open loop, in forces induction, while closed loop may not be necassary, closed loop is better.
RussC[/QUOTE]
Let me clarify this in saying open-loop at WOT not necessarily just under boost .
There are times when I don't want it. Still think the processor between my ears will make better tuning decisions than a 8 bit processor. The MS fuel calculations are the same that many OEM's use, so it's repeatable. You tune it correctly and it stays tuned.
I'm not debating quality of MS product as much as a tuning strategy. Closed loop under boost or WOT is not necessary, IMO.[/QUOTE]
[QUOTE="russc"]My only point would be that a properly running system can run closed loop better than a open loop system. Thats because every varible has been taken into consideration, ALL operating conditions. Theres never a point at which the engine is running outside the FI systems parameters. You never HAVE to listen to the engine, because it's never predetonates. That in itself is a better system, as is in all modern forced induction cars like Mitsu Evo's, Subi's STI's, Benz's SC system, Dodges SRTs ect etc....
While some modern NA cars may still run open loop, in forces induction, while closed loop may not be necassary, closed loop is better.
RussC[/QUOTE]
Let me clarify this in saying open-loop at WOT not necessarily just under boost .
[QUOTE="Matt"]I suspect they didn't add a knock sensor because knock sensors even to this day are highly problematic devices. I have an 88 vintage german vehicle with a knock sensor and its a PITA. I'm thrilled BMW didn't use them.
Read the Jacobs ignition book sometime. Once you train a human to listen for knock, they found that a human can manage ignitition advance better than any of the computer systems they tested.[/QUOTE]
Right, I have had converstions with the inventor of the J&S knock controller, he said the unit is useless at high rpm because the engine makes so much noise it's impossible to design the system to listen for it. In my car works really well to ~4500rpm, then falls down quite noticably.
RussC
Read the Jacobs ignition book sometime. Once you train a human to listen for knock, they found that a human can manage ignitition advance better than any of the computer systems they tested.[/QUOTE]
Right, I have had converstions with the inventor of the J&S knock controller, he said the unit is useless at high rpm because the engine makes so much noise it's impossible to design the system to listen for it. In my car works really well to ~4500rpm, then falls down quite noticably.
RussC
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FirstFives Dictator
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[QUOTE="Duke M535Ti"]The moronic is a TRS-80, Megasquirt - 486 :p and the TEC3 is a pentium M. Why is that so hard to understand?
[Edit by Duke M535Ti on [TIME]1118386025[/TIME]][/QUOTE]
I'm not sure about that. I'm trying to find specs on exactly what's under the hood of Tec3 and not finding it on their site.
Clearly Motronic with 80C31 varients is pretty old fashioned.
Regardless I suspect outcome of a particular application will depend on horsepower of user/installer as much as anything; so the differences are probably moot.
I'm comfortable that my MS has enough under the hood to make my car work well.
For a high mileage b34 motor, I think my e12 scoots along quite well with Megasquirt.
And I can tune it in about 2 hours or so.
[Edit by Duke M535Ti on [TIME]1118386025[/TIME]][/QUOTE]
I'm not sure about that. I'm trying to find specs on exactly what's under the hood of Tec3 and not finding it on their site.
Clearly Motronic with 80C31 varients is pretty old fashioned.
Regardless I suspect outcome of a particular application will depend on horsepower of user/installer as much as anything; so the differences are probably moot.
I'm comfortable that my MS has enough under the hood to make my car work well.
For a high mileage b34 motor, I think my e12 scoots along quite well with Megasquirt.
And I can tune it in about 2 hours or so.
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Jordan528e
- Posts: 109
- Joined: Feb 12, 2006 12:00 PM
Open Loop means that the Cars computer does not look at the O2 sensor, to determine the amount of fuel.
Closed Loop is when the Computer Uses feedback from the O2 sensor to determine the amount of fuel to inject.
You Can tune megasquirt with a wideband o2 on the road, or on a dyno, with a computer hooked up to it.
WOT = Wide Open Throttle (thats when Motronic goes Open Loop).
Closed Loop is when the Computer Uses feedback from the O2 sensor to determine the amount of fuel to inject.
You Can tune megasquirt with a wideband o2 on the road, or on a dyno, with a computer hooked up to it.
WOT = Wide Open Throttle (thats when Motronic goes Open Loop).
[QUOTE="90e34535i"]Open Loop means that the Cars computer does not look at the O2 sensor, to determine the amount of fuel.
Closed Loop is when the Computer Uses feedback from the O2 sensor to determine the amount of fuel to inject.
You Can tune megasquirt with a wideband o2 on the road, or on a dyno, with a computer hooked up to it.
WOT = Wide Open Throttle (thats when Motronic goes Open Loop).[/QUOTE]
While your correct, it's not the full answer. Closed loop would infer all inputs are used for fuel and timing, not just O2. Just being precise, as I was chastisted(BS'd) earlier for not being complete in my answer
On Motronic 1.0 Adaptive('85-'88), it actually goes open loop a alot earlier than WOT, it's starts into acceleration enrichment as soon as the AFM gets to ~>50% open, at that point it goes open loop(ingnores O2).
RussC
Closed Loop is when the Computer Uses feedback from the O2 sensor to determine the amount of fuel to inject.
You Can tune megasquirt with a wideband o2 on the road, or on a dyno, with a computer hooked up to it.
WOT = Wide Open Throttle (thats when Motronic goes Open Loop).[/QUOTE]
While your correct, it's not the full answer. Closed loop would infer all inputs are used for fuel and timing, not just O2. Just being precise, as I was chastisted(BS'd) earlier for not being complete in my answer
On Motronic 1.0 Adaptive('85-'88), it actually goes open loop a alot earlier than WOT, it's starts into acceleration enrichment as soon as the AFM gets to ~>50% open, at that point it goes open loop(ingnores O2).
RussC
[QUOTE="Duke M535Ti"]The moronic is a TRS-80, Megasquirt - 486 :p and the TEC3 is a pentium M. Why is that so hard to understand?
[Edit by Duke M535Ti on [TIME]1118386025[/TIME]][/QUOTE]
[QUOTE="FirstFives Dictator"]
Clearly Motronic with 80C31 varients is pretty old fashioned. [/QUOTE]
The 80C31 is a 8051 variant. Actually, the 8051 micro controller is very good CPU. Especially the modern updates from Phillips, the 80C52's. The 80C52 have all the RAM, ROM, ADC, PWM and other I/O that would help the Motronics alot. And with all the speed increases, would make a good processor for a modern FI system. It's jus that in 1980s, that was state of the art, now it seems primitive by comparison.
RussC
[Edit by Duke M535Ti on [TIME]1118386025[/TIME]][/QUOTE]
[QUOTE="FirstFives Dictator"]
Clearly Motronic with 80C31 varients is pretty old fashioned. [/QUOTE]
The 80C31 is a 8051 variant. Actually, the 8051 micro controller is very good CPU. Especially the modern updates from Phillips, the 80C52's. The 80C52 have all the RAM, ROM, ADC, PWM and other I/O that would help the Motronics alot. And with all the speed increases, would make a good processor for a modern FI system. It's jus that in 1980s, that was state of the art, now it seems primitive by comparison.
RussC
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Velocewest
- Posts: 1558
- Joined: Feb 12, 2006 12:00 PM
- Location: UK
What a classic "Mine's bigger!" thread. %)
The original question was, in a nutshell, "will modern FI work better than Motronic?" The answer is, "Maybe, depends on how you will drive the car."
And as to the argument that Tec3 is better than MegaSquirt? Well, for roughly 3 times the price (maybe more), I'd be seriously F'ing pissed if it wasn't.
And I have a feeling I would be pissed, because I'd be paying 3 times MS price for the capability to improve the last 5% of my car's potential. If you're Duke or Ken H, who have clearly lost their minds in a most delightful way :p I'm sure that makes sense. It doesn't for most of us, who don't have bottomless development budgets. We'll be fine with MS, and over time, the open-source nature of MS will let us continue to improve for chump change.
The original question was, in a nutshell, "will modern FI work better than Motronic?" The answer is, "Maybe, depends on how you will drive the car."
And as to the argument that Tec3 is better than MegaSquirt? Well, for roughly 3 times the price (maybe more), I'd be seriously F'ing pissed if it wasn't.
And I have a feeling I would be pissed, because I'd be paying 3 times MS price for the capability to improve the last 5% of my car's potential. If you're Duke or Ken H, who have clearly lost their minds in a most delightful way :p I'm sure that makes sense. It doesn't for most of us, who don't have bottomless development budgets. We'll be fine with MS, and over time, the open-source nature of MS will let us continue to improve for chump change.
[QUOTE="Velocewest"]What a classic "Mine's bigger!" thread. %)
The original question was, in a nutshell, "will modern FI work better than Motronic?" The answer is, "Maybe, depends on how you will drive the car."
And as to the argument that Tec3 is better than MegaSquirt? Well, for roughly 3 times the price (maybe more), I'd be seriously F'ing pissed if it wasn't.
And I have a feeling I would be pissed, because I'd be paying 3 times MS price for the capability to improve the last 5% of my car's potential. If you're Duke or Ken H, who have clearly lost their minds in a most delightful way :p I'm sure that makes sense. It doesn't for most of us, who don't have bottomless development budgets. We'll be fine with MS, and over time, the open-source nature of MS will let us continue to improve for chump change. [/QUOTE]
I agree. I wouldn't ever dump Motronic unless I out grew it ability to accomodate my boost level.
Todd
The original question was, in a nutshell, "will modern FI work better than Motronic?" The answer is, "Maybe, depends on how you will drive the car."
And as to the argument that Tec3 is better than MegaSquirt? Well, for roughly 3 times the price (maybe more), I'd be seriously F'ing pissed if it wasn't.
And I have a feeling I would be pissed, because I'd be paying 3 times MS price for the capability to improve the last 5% of my car's potential. If you're Duke or Ken H, who have clearly lost their minds in a most delightful way :p I'm sure that makes sense. It doesn't for most of us, who don't have bottomless development budgets. We'll be fine with MS, and over time, the open-source nature of MS will let us continue to improve for chump change.
[/QUOTE]I agree. I wouldn't ever dump Motronic unless I out grew it ability to accomodate my boost level.
Todd
[QUOTE="Velocewest"]What a classic "Mine's bigger!" thread. %)
The original question was, in a nutshell, "will modern FI work better than Motronic?" The answer is, "Maybe, depends on how you will drive the car."
And as to the argument that Tec3 is better than MegaSquirt? Well, for roughly 3 times the price (maybe more), I'd be seriously F'ing pissed if it wasn't.
And I have a feeling I would be pissed, because I'd be paying 3 times MS price for the capability to improve the last 5% of my car's potential. If you're Duke or Ken H, who have clearly lost their minds in a most delightful way :p I'm sure that makes sense. It doesn't for most of us, who don't have bottomless development budgets. We'll be fine with MS, and over time, the open-source nature of MS will let us continue to improve for chump change. [/QUOTE]
[QUOTE="TCD"]I agree. I wouldn't ever dump Motronic unless I out grew it ability to accomodate my boost level.
Todd[/QUOTE]
Dumping the AFM is another good reason to dump Motronic.
The original question was, in a nutshell, "will modern FI work better than Motronic?" The answer is, "Maybe, depends on how you will drive the car."
And as to the argument that Tec3 is better than MegaSquirt? Well, for roughly 3 times the price (maybe more), I'd be seriously F'ing pissed if it wasn't.
And I have a feeling I would be pissed, because I'd be paying 3 times MS price for the capability to improve the last 5% of my car's potential. If you're Duke or Ken H, who have clearly lost their minds in a most delightful way :p I'm sure that makes sense. It doesn't for most of us, who don't have bottomless development budgets. We'll be fine with MS, and over time, the open-source nature of MS will let us continue to improve for chump change.
[/QUOTE][QUOTE="TCD"]I agree. I wouldn't ever dump Motronic unless I out grew it ability to accomodate my boost level.
Todd[/QUOTE]
Dumping the AFM is another good reason to dump Motronic.
[QUOTE="Ken H."]TCD, check yr email: tcd@turbochargingdynamics.com.
As for going off the deep end with a TEC-3r vs. MS. The issue was about capabilities; the TEC units being more of a plug-and-play setup. Not that that's what it's turning into, but that's where it was when I made the decision. Additionally, the Electromotive stuff seems to be more compatible with FI applications and eliminates the Motronic entirely. Duke has it right with his analogy to a TRS-80 vs. a -486 vs. a Pentium. There are some systems which (may) offer another level of flexibility. To name two, HalTech and MoTeC. Just siddown when you go into MoTeC's website. ~0 [/QUOTE]
To unlock to nifty extras in MoTec is going to cost MoMoney. The ultimate is not cheap.
As for going off the deep end with a TEC-3r vs. MS. The issue was about capabilities; the TEC units being more of a plug-and-play setup. Not that that's what it's turning into, but that's where it was when I made the decision. Additionally, the Electromotive stuff seems to be more compatible with FI applications and eliminates the Motronic entirely. Duke has it right with his analogy to a TRS-80 vs. a -486 vs. a Pentium. There are some systems which (may) offer another level of flexibility. To name two, HalTech and MoTeC. Just siddown when you go into MoTeC's website. ~0 [/QUOTE]
To unlock to nifty extras in MoTec is going to cost MoMoney. The ultimate is not cheap.
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FirstFives Dictator
- Posts: 849
- Joined: Feb 12, 2006 12:00 PM
- Location: Virginia Beach, VA
- Contact:
[QUOTE="Ken H."]TCD, check yr email: tcd@turbochargingdynamics.com.
As for going off the deep end with a TEC-3r vs. MS. The issue was about capabilities; the TEC units being more of a plug-and-play setup. Not that that's what it's turning into, but that's where it was when I made the decision. Additionally, the Electromotive stuff seems to be more compatible with FI applications and eliminates the Motronic entirely. Duke has it right with his analogy to a TRS-80 vs. a -486 vs. a Pentium. There are some systems which (may) offer another level of flexibility. To name two, HalTech and MoTeC. Just siddown when you go into MoTeC's website. ~0 [/QUOTE]
One thing that has not beed talked about: The Tec-3r is probably much less application-sensitive. I've modified every one I've built or installed to make sure it 'drops in' nicely into it's application. Badly engineered installations are part of why some folks have MS problems; other part is that fact that they built MS boxes themselves; most folks don't know how to solder well and don't have this:
http://www.howardelectronics.com/jbc/ad2700.html
which is about $500.00 worth of soldering station. Yes,I take reliable soldering seriously.
By knowing how each MS is going to be applied I can make sure there's no interface issues. I didn't want a call from TCD, stranded somewhere between SC and OH.
As for going off the deep end with a TEC-3r vs. MS. The issue was about capabilities; the TEC units being more of a plug-and-play setup. Not that that's what it's turning into, but that's where it was when I made the decision. Additionally, the Electromotive stuff seems to be more compatible with FI applications and eliminates the Motronic entirely. Duke has it right with his analogy to a TRS-80 vs. a -486 vs. a Pentium. There are some systems which (may) offer another level of flexibility. To name two, HalTech and MoTeC. Just siddown when you go into MoTeC's website. ~0 [/QUOTE]
One thing that has not beed talked about: The Tec-3r is probably much less application-sensitive. I've modified every one I've built or installed to make sure it 'drops in' nicely into it's application. Badly engineered installations are part of why some folks have MS problems; other part is that fact that they built MS boxes themselves; most folks don't know how to solder well and don't have this:
http://www.howardelectronics.com/jbc/ad2700.html
which is about $500.00 worth of soldering station. Yes,I take reliable soldering seriously.
By knowing how each MS is going to be applied I can make sure there's no interface issues. I didn't want a call from TCD, stranded somewhere between SC and OH.
[QUOTE="wjones"]Dumping the AFM is another good reason to dump Motronic.[/QUOTE]
Got proof? I have yet to see a single piece of real evidence that says the AFM is this big huge restriction that everyone likes to think it is.
People who go to an MAF setup have reported increased throttle response. OK, that just means that an MAF reacts faster to changes in the incoming air volume faster than the AFM can. Given that the AFM is a spring based system, that's a perfectly understandable limitation.
The only other "evidence" I've seen was Duke's MAF vs AFM dyno curves. However, if memory serves, the A/F ratio was messed up on the AFM pull, so that doesn't count.
A lot of people seem to have an "it's old, so it must suck" philosophy. In some cases I suppose this is true, but the AFM really isn't all that bad.
[QUOTE="russc"]On Motronic 1.0 Adaptive('85-'88), it actually goes open loop a alot earlier than WOT, it's starts into acceleration enrichment as soon as the AFM gets to ~>50% open, at that point it goes open loop(ingnores O2).[/QUOTE]
Where does this information come from? My experience with a wideband O2 sensor directly condradicts that. A/F ratio stays at 14.7:1 until the throttle gets opened all the way, even under 6-8psi of boost.
Jeremy
[Edit by Jeremy on [TIME]1118839407[/TIME]]
Got proof? I have yet to see a single piece of real evidence that says the AFM is this big huge restriction that everyone likes to think it is.
People who go to an MAF setup have reported increased throttle response. OK, that just means that an MAF reacts faster to changes in the incoming air volume faster than the AFM can. Given that the AFM is a spring based system, that's a perfectly understandable limitation.
The only other "evidence" I've seen was Duke's MAF vs AFM dyno curves. However, if memory serves, the A/F ratio was messed up on the AFM pull, so that doesn't count.
A lot of people seem to have an "it's old, so it must suck" philosophy. In some cases I suppose this is true, but the AFM really isn't all that bad.
[QUOTE="russc"]On Motronic 1.0 Adaptive('85-'88), it actually goes open loop a alot earlier than WOT, it's starts into acceleration enrichment as soon as the AFM gets to ~>50% open, at that point it goes open loop(ingnores O2).[/QUOTE]
Where does this information come from? My experience with a wideband O2 sensor directly condradicts that. A/F ratio stays at 14.7:1 until the throttle gets opened all the way, even under 6-8psi of boost.
Jeremy
[Edit by Jeremy on [TIME]1118839407[/TIME]]
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FirstFives Dictator
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[QUOTE="wjones"]Dumping the AFM is another good reason to dump Motronic.[/QUOTE]
[QUOTE="Jeremy"]Got proof? I have yet to see a single piece of real evidence that says the AFM is this big huge restriction that everyone likes to think it is.
People who go to an MAF setup have reported increased throttle response. OK, that just means that an MAF reacts faster to changes in the incoming air velocity faster than the AFM can. Given that the AFM is a spring based system, that's perfectly understandable.
The only other "evidence" I've seen was Duke's MAF vs AFM dyno curves. However, if memory serves, the A/F ratio was messed up on the AFM pull, so that doesn't count.
A lot of people seem to have an "it's old, so it must suck" philosophy. In some cases I suppose this is true, but the AFM really isn't all that bad.
Jeremy[/QUOTE]
Honest answer: there's no free lunch. I lost a little low-end torque when going from AFM to carbon fiber tube (both with MS controlling it) but top end was better.
I drive an e12. I can't have an "it's old, so it must suck" attitude.
[QUOTE="Jeremy"]Got proof? I have yet to see a single piece of real evidence that says the AFM is this big huge restriction that everyone likes to think it is.
People who go to an MAF setup have reported increased throttle response. OK, that just means that an MAF reacts faster to changes in the incoming air velocity faster than the AFM can. Given that the AFM is a spring based system, that's perfectly understandable.
The only other "evidence" I've seen was Duke's MAF vs AFM dyno curves. However, if memory serves, the A/F ratio was messed up on the AFM pull, so that doesn't count.
A lot of people seem to have an "it's old, so it must suck" philosophy. In some cases I suppose this is true, but the AFM really isn't all that bad.
Jeremy[/QUOTE]
Honest answer: there's no free lunch. I lost a little low-end torque when going from AFM to carbon fiber tube (both with MS controlling it) but top end was better.
I drive an e12. I can't have an "it's old, so it must suck" attitude.
-
FirstFives Dictator
- Posts: 849
- Joined: Feb 12, 2006 12:00 PM
- Location: Virginia Beach, VA
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[QUOTE="FirstFives Dictator"]One thing that has not beed talked about: The Tec-3r is probably much less application-sensitive. I've modified every one I've built or installed to make sure it 'drops in' nicely into it's application.[/QUOTE]
Corrections:
has not been talked about.
Also, I've modified Megasquirts not Tec-3r which was my point (poorly made)
Corrections:
has not been talked about.
Also, I've modified Megasquirts not Tec-3r which was my point (poorly made)
[QUOTE="wjones"]Dumping the AFM is another good reason to dump Motronic.[/QUOTE]
Got proof? I have yet to see a single piece of real evidence that says the AFM is this big huge restriction that everyone likes to think it is.
People who go to an MAF setup have reported increased throttle response. OK, that just means that an MAF reacts faster to changes in the incoming air volume faster than the AFM can. Given that the AFM is a spring based system, that's a perfectly understandable limitation.
The only other "evidence" I've seen was Duke's MAF vs AFM dyno curves. However, if memory serves, the A/F ratio was messed up on the AFM pull, so that doesn't count.
A lot of people seem to have an "it's old, so it must suck" philosophy. In some cases I suppose this is true, but the AFM really isn't all that bad.
[QUOTE="russc"]On Motronic 1.0 Adaptive('85-'88), it actually goes open loop a alot earlier than WOT, it's starts into acceleration enrichment as soon as the AFM gets to ~>50% open, at that point it goes open loop(ingnores O2).[/QUOTE]
Where does this information come from? My experience with a wideband O2 sensor directly condradicts that. A/F ratio stays at 14.7:1 until the throttle gets opened all the way, even under 6-8psi of boost.
Jeremy
[Edit by Jeremy on [TIME]1118839407[/TIME]]
[QUOTE="Jeremy"]Got proof? I have yet to see a single piece of real evidence that says the AFM is this big huge restriction that everyone likes to think it is.
People who go to an MAF setup have reported increased throttle response. OK, that just means that an MAF reacts faster to changes in the incoming air volume faster than the AFM can. Given that the AFM is a spring based system, that's a perfectly understandable limitation.
The only other "evidence" I've seen was Duke's MAF vs AFM dyno curves. However, if memory serves, the A/F ratio was messed up on the AFM pull, so that doesn't count.
A lot of people seem to have an "it's old, so it must suck" philosophy. In some cases I suppose this is true, but the AFM really isn't all that bad.
Where does this information come from? My experience with a wideband O2 sensor directly condradicts that. A/F ratio stays at 14.7:1 until the throttle gets opened all the way, even under 6-8psi of boost.
Jeremy
[Edit by Jeremy on [TIME]1118839407[/TIME]][/QUOTE]
In the interest of minimizing my typing. Visit s14.net. IIRC there are several dyno plots posted there of AFM vs. Alpha-N control on an S14. I KNOW it works in that app. and I have little doubt there will be an improvement on my "dirty" motor. It is a big restriction in your intake path. The trottle response gained was worth the effort.
Got proof? I have yet to see a single piece of real evidence that says the AFM is this big huge restriction that everyone likes to think it is.
People who go to an MAF setup have reported increased throttle response. OK, that just means that an MAF reacts faster to changes in the incoming air volume faster than the AFM can. Given that the AFM is a spring based system, that's a perfectly understandable limitation.
The only other "evidence" I've seen was Duke's MAF vs AFM dyno curves. However, if memory serves, the A/F ratio was messed up on the AFM pull, so that doesn't count.
A lot of people seem to have an "it's old, so it must suck" philosophy. In some cases I suppose this is true, but the AFM really isn't all that bad.
[QUOTE="russc"]On Motronic 1.0 Adaptive('85-'88), it actually goes open loop a alot earlier than WOT, it's starts into acceleration enrichment as soon as the AFM gets to ~>50% open, at that point it goes open loop(ingnores O2).[/QUOTE]
Where does this information come from? My experience with a wideband O2 sensor directly condradicts that. A/F ratio stays at 14.7:1 until the throttle gets opened all the way, even under 6-8psi of boost.
Jeremy
[Edit by Jeremy on [TIME]1118839407[/TIME]]
[QUOTE="Jeremy"]Got proof? I have yet to see a single piece of real evidence that says the AFM is this big huge restriction that everyone likes to think it is.
People who go to an MAF setup have reported increased throttle response. OK, that just means that an MAF reacts faster to changes in the incoming air volume faster than the AFM can. Given that the AFM is a spring based system, that's a perfectly understandable limitation.
The only other "evidence" I've seen was Duke's MAF vs AFM dyno curves. However, if memory serves, the A/F ratio was messed up on the AFM pull, so that doesn't count.
A lot of people seem to have an "it's old, so it must suck" philosophy. In some cases I suppose this is true, but the AFM really isn't all that bad.
Where does this information come from? My experience with a wideband O2 sensor directly condradicts that. A/F ratio stays at 14.7:1 until the throttle gets opened all the way, even under 6-8psi of boost.
Jeremy
[Edit by Jeremy on [TIME]1118839407[/TIME]][/QUOTE]
In the interest of minimizing my typing. Visit s14.net. IIRC there are several dyno plots posted there of AFM vs. Alpha-N control on an S14. I KNOW it works in that app. and I have little doubt there will be an improvement on my "dirty" motor. It is a big restriction in your intake path. The trottle response gained was worth the effort.
Guys,
Ive seen this thread before. I also just went to the S14.net website, but the dyno graphs are down. So I read some of the forums. Listen please,
The AFM to MAF conversion will yeild just a slight bit of power on the top end, a little more in the middle range, IF, you make a APPLES TO APPLES comparison, not a apples to oranges comparison. Let me expain.
As Ive seen, and know from talking about the issue from Dinan(Steve himself), the AFM restricts very little at the top end. Once the flap is open, there is almost nil restriction, so the top end perfromance is little effected. This is where the apples to apples comes in. Whats the difference from a well tuned AFM system to a tuned MAF system, thats the key. Comparing a stock AFM system to a tuned MAF system is not a valid comparison. If you custom tune your AFM system, you will get more power from it. The stock system is a compromise so it works across all cars off the assembly line. That means most cars will make more power with a properly tuned Motronic system. Thats why tuners like Dinan, JImC, AutoAthority ect all made aftermarfet chips for these cars, and thats still a compromise. Then you can compare a tuned car to tuned car to make a valid comparison, GET IT!!!!!!!!!!!!!!!!!!!!!!!! This is the biggest mistake people make when comparing AFM to MAF conversions.
RussC
Ive seen this thread before. I also just went to the S14.net website, but the dyno graphs are down. So I read some of the forums. Listen please,
The AFM to MAF conversion will yeild just a slight bit of power on the top end, a little more in the middle range, IF, you make a APPLES TO APPLES comparison, not a apples to oranges comparison. Let me expain.
As Ive seen, and know from talking about the issue from Dinan(Steve himself), the AFM restricts very little at the top end. Once the flap is open, there is almost nil restriction, so the top end perfromance is little effected. This is where the apples to apples comes in. Whats the difference from a well tuned AFM system to a tuned MAF system, thats the key. Comparing a stock AFM system to a tuned MAF system is not a valid comparison. If you custom tune your AFM system, you will get more power from it. The stock system is a compromise so it works across all cars off the assembly line. That means most cars will make more power with a properly tuned Motronic system. Thats why tuners like Dinan, JImC, AutoAthority ect all made aftermarfet chips for these cars, and thats still a compromise. Then you can compare a tuned car to tuned car to make a valid comparison, GET IT!!!!!!!!!!!!!!!!!!!!!!!! This is the biggest mistake people make when comparing AFM to MAF conversions.
RussC
The only other "evidence" I've seen was Duke's MAF vs AFM dyno curves. However, if memory serves, the A/F ratio was messed up on the AFM pull, so that doesn't count.
Here is the dyno graph (red, MAF - Blue, AFM). Same dyno, same day(two hours apart), same temp, same engine, same modifications, same piggy back computer controlling the A/F on BOTH runs. So the A/F was the same (screwed up or not) for both.
You can see they the MAF made more power, period. AFM is crap. Look at 5100 rpm, MAF made 30 HP more. And as mentioned, the throttle response was 100% better.
There is your evidence.
Duke, do you have the AFR curves for those pulls or did they not give them to you? Just wondering. Something massive happened on that AFM pull at 5250 rpm, I'm guessing a dead spot of some such in the AFM, and I think that was what was generally agreed upon when you first posted this.
In any case, the MAF on a fairly modified motor seems to gain 10rwtq across most of the rev range. Don't even try to claim a 30HP increase where that dead spot is. I'm still dubious unless I can see that the AFR curves were exactly the same, but that's still not a whole lot of gain for the price of the conversion in my mind. If you're looking for power, I still don't think ditching the AFM is a good way to do it. The increased throttle response alone probably makes it worthwhile to some.
Jeremy
In any case, the MAF on a fairly modified motor seems to gain 10rwtq across most of the rev range. Don't even try to claim a 30HP increase where that dead spot is. I'm still dubious unless I can see that the AFR curves were exactly the same, but that's still not a whole lot of gain for the price of the conversion in my mind. If you're looking for power, I still don't think ditching the AFM is a good way to do it. The increased throttle response alone probably makes it worthwhile to some.
Jeremy
[QUOTE="Sweeney"]I'm going to eliminate all engine management. I plan to pressurize the fuel tank with exhaust and boost pressure. The fuel line will run to a ball valve and then directly into the intake plenum. The ball valve will be actuated off a linkage from the throttle body.[/QUOTE]
Yes, but you're a certified mad scientist and operate outside the realm of us normal humans.
Jeremy
PS - you going to use a rear mounted turbo for that? It'd make it a lot closer to the fuel tank.
Yes, but you're a certified mad scientist and operate outside the realm of us normal humans.
Jeremy
PS - you going to use a rear mounted turbo for that? It'd make it a lot closer to the fuel tank.
The only other "evidence" I've seen was Duke's MAF vs AFM dyno curves. However, if memory serves, the A/F ratio was messed up on the AFM pull, so that doesn't count.
This evidence actually proves the proper theory, mine. Even with the bad AFM run, look at the 5500 to 6000rpm portion of the dyno run. When the AFM system recovered, the HP/torque curves are very close, maybe a 5 difference. The middle portion of the run shows the benefit of the MAF, but the benefit decreases as the flap opens more, your curve shows that explicitly. The bad AFM run is exactly like Raj's dyno run that is up on TCD's web site as the "M30 respresentative" dyno chart. Well, it's not. As a side point, I think Raj fixed his issue with a AFM swap?, but I can't quite remember, Raj? It could also as stated above, AFM dead spot. That bad run might also be due to adaptation trying to figure out what happened from the differences in the air metering device input!Duke M535Ti wrote:
Here is the dyno graph (red, MAF - Blue, AFM). Same dyno, same day(two hours apart), same temp, same engine, same modifications, same piggy back computer controlling the A/F on BOTH runs. So the A/F was the same (screwed up or not) for both.
You can see they the MAF made more power, period. AFM is crap. Look at 5100 rpm, MAF made 30 HP more. And as mentioned, the throttle response was 100% better.
There is your evidence.
RussC
[Edit by russc on [TIME]1118947614[/TIME]]