 |
Matronics Email Lists
Web Forum Interface to the Matronics Email Lists
|
| View previous topic :: View next topic |
| Author |
Message |
speedy11(at)aol.com
Guest
|
 Posted: Fri Aug 30, 2013 9:32 am Post subject: AFR Meter |
 |
|
I suppose I should know about them, but I'm not familiar with measuring the air-fuel ratio. The technique is apparently used with automotive racing engines to fine tune the air fuel mixture to optimize power output.
Does anyone know if that concept and equipment has been applied to an OBAM aircraft?
It sounds like an interesting and plausible concept.
Stan Sutterfield
Reno Race 84
| Quote: | | Quote: | > snip... I'm already familiar with them and they make good stuff!
| Quote: | The company is called PLX Devices, and they make incredible high quality
products,
|
gages,
| Quote: | etc, mostly for the auto industry.
snip...
Mike Welch
|
I can attest to the high quality, simple operation of the PLX's Air Fuel Ratio
Meter. Probably the simplest, no-brainer way to tune EFI. I installed a Simple
Digital Systems EFI on a Franklin 6 cylinder and set it up using the PLX device.
Amounted to putting a temporary O2 sensor in the 3 into 1 collector on one
cylinder bank and connecting to the PLX device (velcroed to my panel) and gauge.
Start the engine and your real-time air fuel ratio is displayed. Change the
mixture (fuel value) on the EFI and watch the gauge reflect the change. Set
it up for 12.5 to 1 max power at 250 RPM increments in the useable RPM range.
Took about 15 minutes to map the 5 point rpm fuel curve.
When I was done, I had the feeling that it couldn't be that simple.
It was.
The gauge is nice looking with it's digital display and progressive LED
"needle", |
|
[quote][b]
| | - The Matronics AeroElectric-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
|
|
|
| Back to top |
|
 |
dee.whittington(at)gmail.
Guest
|
| Posted: Fri Aug 30, 2013 10:17 am Post subject: AFR Meter |
|
|
This is done as standard procedure with Eggenfellner Subaru engines which have and SDS (Simplified Digital Systems) engine computer. http://sdsefi.com/ We've installed an AIR/FUEL RATIO knob on our sub-panel next to the throttle as highly suggested by Ross Farnham, the owner of SDS. We have an O2 sensor we bought from Ross on our left cylinder bank exhaust just below the point where the three left cylinders exhaust stacks merge into one exhaust pipe. We will monitor the AIR/FUEL ratio in our case with the SDS programmer which we also bought from Ross. Ross, who is in Calgary, Alberta, Canada, is a wizard with racing Subaru engines.
Dee
DeWitt (Dee) Whittington804-677-4849 iPhone
804-358-4333 Home
On Fri, Aug 30, 2013 at 1:31 PM, <speedy11(at)aol.com (speedy11(at)aol.com)> wrote:
[quote] I suppose I should know about them, but I'm not familiar with measuring the air-fuel ratio. The technique is apparently used with automotive racing engines to fine tune the air fuel mixture to optimize power output.
Does anyone know if that concept and equipment has been applied to an OBAM aircraft?
It sounds like an interesting and plausible concept.
Stan Sutterfield
Reno Race 84
| Quote: | | Quote: | > snip... I'm already familiar with them and they make good stuff!
| Quote: | The company is called PLX Devices, and they make incredible high quality
products,
|
gages,
| Quote: | etc, mostly for the auto industry.
snip...
Mike Welch
|
I can attest to the high quality, simple operation of the PLX's Air Fuel Ratio
Meter. Probably the simplest, no-brainer way to tune EFI. I installed a Simple
Digital Systems EFI on a Franklin 6 cylinder and set it up using the PLX device.
Amounted to putting a temporary O2 sensor in the 3 into 1 collector on one
cylinder bank and connecting to the PLX device (velcroed to my panel) and gauge.
Start the engine and your real-time air fuel ratio is displayed. Change the
mixture (fuel value) on the EFI and watch the gauge reflect the change. Set
it up for 12.5 to 1 max power at 250 RPM increments in the useable RPM range.
Took about 15 minutes to map the 5 point rpm fuel curve.
When I was done, I had the feeling that it couldn't be that simple.
It was.
The gauge is nice looking with it's digital display and progressive LED
"needle", |
|
| Quote: |
ist" target="_blank">http://www.matronics.com/Navigator?AeroElectric-List
tp://forums.matronics.com
_blank">http://www.matronics.com/contribution
|
[b]
| | - The Matronics AeroElectric-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
|
|
|
| Back to top |
|
|
Mike Welch
Joined: 13 Feb 2011
Posts: 272
|
| Posted: Fri Aug 30, 2013 10:38 am Post subject: AFR Meter |
|
|
| Quote: | snip>
Does anyone know if that concept and equipment has been applied to an OBAM aircraft?
It sounds like an interesting and plausible concept. <snip
Stan Sutterfield
Reno Race 84
|
Stan,
My familiarity with them came when I bought their Air/Fuel wideband O2 meter and sender.
The reason I bought the gage is I needed a way monitor the fine tuning the AFR (air/fuel ratio)
for my custom turbo installation on my GEO engine.
The engine on my plane came as a normally aspirated GEO (Suzuki) engine. The stock engine control unit
( the ECU) can take care of up to 5 psi boost "automatically". I wanted a little bit more than 5 (more like 7-8 psi).
Therefore, I used a common practice in the hotrod field is to "trick" the engine into thinking it is COLD,
thereby adding more fuel. You do this by replacing the coolant temperature sensor with a simple circuit where you
can determine the resistance the sensor 'was' going to send to the ECU. BY increasing the resistance, the
ECU thinks the engine is cold. This is known as the CTS mod (coolant temperature sensor mod).
This method allows one to add a mild turbocharger to an otherwise non-turboed engine fairly easily.
In addition to the obvious boost gage to monitor turbo boost, you need an AFR gage to determine
you're not running too lean. If you are….you just dial in some more "artificial cold" to the ECU, and
it increases the fuel injector's pulses, enriching the fuel supply to the engine.
Anyway, that's how I came across them. They seem to make quality products. I thought the
'smart battery charger' might be useful to some pilots who carry several gadgets with them and
could use a great 'safety' back-up charger. FWIW.
Mike Welch
[quote][b]
| | - The Matronics AeroElectric-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
|
|
|
| Back to top |
|
|
nuckolls.bob(at)aeroelect
Guest
|
| Posted: Fri Aug 30, 2013 3:29 pm Post subject: AFR Meter |
|
|
At 12:31 PM 8/30/2013, you wrote:
| Quote: | I suppose I should know about them, but I'm not familiar with measuring the air-fuel ratio. The technique is apparently used with automotive racing engines to fine tune the air fuel mixture to optimize power output.
Does anyone know if that concept and equipment has been applied to an OBAM aircraft?
It sounds like an interesting and plausible concept.
Stan Sutterfield
Reno Race 84 |
An engine guru explained the O2 sensor this
Bob . . . [quote][b]
| | - The Matronics AeroElectric-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
|
|
|
| Back to top |
|
|
raymondj(at)frontiernet.n
Guest
|
| Posted: Fri Aug 30, 2013 3:39 pm Post subject: AFR Meter |
|
|
Mark Langford has a Corvair/KR2 site that tells his experience using an O2 sensor to fine tune the fuel mixture. Well worth the time to look at if you're considering an O2 sensor.
| Quote: | Raymond Julian
Kettle River, MN.
"And you know that I could have me a million more friends,
and all I'd have to lose is my point of view." - John Prine |
On 08/30/2013 12:31 PM, speedy11(at)aol.com (speedy11(at)aol.com) wrote:
[quote] I suppose I should know about them, but I'm not familiar with measuring the air-fuel ratio. The technique is apparently used with automotive racing engines to fine tune the air fuel mixture to optimize power output.
Does anyone know if that concept and equipment has been applied to an OBAM aircraft?
It sounds like an interesting and plausible concept.
Stan Sutterfield
Reno Race 84
| Quote: | | Quote: | > snip... I'm already familiar with them and they make good stuff!
| Quote: | The company is called PLX Devices, and they make incredible high quality
products,
|
gages,
| Quote: | etc, mostly for the auto industry.
snip...
Mike Welch
|
I can attest to the high quality, simple operation of the PLX's Air Fuel Ratio
Meter. Probably the simplest, no-brainer way to tune EFI. I installed a Simple
Digital Systems EFI on a Franklin 6 cylinder and set it up using the PLX device.
Amounted to putting a temporary O2 sensor in the 3 into 1 collector on one
cylinder bank and connecting to the PLX device (velcroed to my panel) and gauge.
Start the engine and your real-time air fuel ratio is displayed. Change the
mixture (fuel value) on the EFI and watch the gauge reflect the change. Set
it up for 12.5 to 1 max power at 250 RPM increments in the useable RPM range.
Took about 15 minutes to map the 5 point rpm fuel curve.
When I was done, I had the feeling that it couldn't be that simple.
It was.
The gauge is nice looking with it's digital display and progressive LED
"needle", |
|
[b]
| | - The Matronics AeroElectric-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
|
|
|
| Back to top |
|
|
nuckolls.bob(at)aeroelect
Guest
|
| Posted: Fri Aug 30, 2013 3:40 pm Post subject: AFR Meter |
|
|
At 12:31 PM 8/30/2013, you wrote:
| Quote: | I suppose I should know about them, but I'm not familiar with measuring the air-fuel ratio. The technique is apparently used with automotive racing engines to fine tune the air fuel mixture to optimize power output.
Does anyone know if that concept and equipment has been applied to an OBAM aircraft?
It sounds like an interesting and plausible concept.
Stan Sutterfield
Reno Race 84 |
An engine guru explained the O2 sensor to me
at OSH a few years back. It response to the
presence of any oxygen in the exhaust gas stream
and unless fitted with an electrical heater,
doesn't give out useful information until it's
warmed up by the exhaust.
The output voltage is a function of oxygen
concentration . . . so any mixture running
lean will use up all the fuel with oxygen
left over . . . hence some voltage will
be generated. Stoichiometric mixture will
produce zero volts . . . mixture richer
than stoichiometric will also produce zero
volts.
These sensors have been used on OBAM aircraft
for many years. Contrary to popular myth, leaded
fuel doesn't seem to 'clog them up' . . . I've
met two pilots flying them in 100LL fueled aircraft
with useful performance. In both cases, adjusting
mixture for xx.x millivolts on a display produced
an accurate and repeatable setting of 'xx degress
lean of peak' . . .
The agile fuel injection computer can be fitted
with mathematical smarts to extrapolate injector
timing for performance goals on the rich side of
stoichiometric.
The output voltage is, as I recall, small . . .
tens of millivolts. Useful application usually
calls for some active signal conditioning
for presentation on a display.
The short answer is, "Yes, an automotive O2
sensor can be a significant component of your
operating design goals.
Bob . . . [quote][b]
| | - The Matronics AeroElectric-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
|
|
|
| Back to top |
|
|
jonlaury
Joined: 06 Nov 2006
Posts: 336
|
| Posted: Sat Aug 31, 2013 7:51 am Post subject: Re: AFR Meter |
|
|
[quote="nuckolls.bob(at)aeroelect"]
....
These sensors have been used on OBAM aircraft
for many years. Contrary to popular myth, leaded
fuel doesn't seem to 'clog them up' . . . I've
met two pilots flying them in 100LL fueled aircraft
with useful performance.
...
The short answer is, "Yes, an automotive O2
sensor can be a significant component of your
operating design goals.
Bob . . .
I used Decalin (sp?) lead scavenger from ACS in my 100LL fuel during fuel mapping to prevent lead clogging of the $70 + Bosch O2 sensor. If you want to run a fully functioning altitude compensating EFI, then you need to leave the O2 sensor in the exhaust stream. I used the sensor just to set up my EFI for 12.5 to 1 AFR at max power and will do conventional fine tuning/leaning at <100% from EGTs. This is the first I've heard of lead not being an issue for O2 sensors, but I've heard a few anecdotal reports of lead fouling of O2 sensors.
Once fuel mapping was complete, there was no need for the PLX meter in the cockpit, nor for the O2 sensor on the exhaust unless I make changes to the induction system or fuel delivery components.
John
| | - The Matronics AeroElectric-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
|
|
|
| Back to top |
|
|
klehman(at)albedo.net
Guest
|
| Posted: Sun Sep 01, 2013 12:25 pm Post subject: AFR Meter |
|
|
I'd suggest that the life of the O2 sensor is indeed significantly
shortened running on leaded fuel. Also significantly shortened if it
runs too hot such as installed in the automotive location and subjected
to continuous relatively high power aircraft operation. Shielding them
helps.
The classic narrow band sensor could be thought of as almost a
stoichometric switch outputting between 0 and 1 volt. Easilly seen with
a Digital Volt Meter. Useful for setting a 14.7:1 gasolene stoichometric
mixture to keep a catalytic converter happy or for indicating which side
of stoichometric any engine is running at.
The modern Air Fuel Ratio sensor (wide band sensor) will give the actual
mixture but these require somewhat sophisticated electronic control and
signal conditioning. Prices have come down to as low as a couple of
hundred dollars but these are definitely not the cheap under $100. bar
graph displays driven by a LM3914 chip that one sees advertised.
Both types of sensors have been used in OBAM aircraft. Useful for tuning
but I consider them unsuitable to run continuously on avgas even when
using a lead scavenger such as Decalin.
Ken
On 30/08/2013 7:39 PM, Robert L. Nuckolls, III wrote:
| Quote: | At 12:31 PM 8/30/2013, you wrote:
> I suppose I should know about them, but I'm not familiar with
> measuring the air-fuel ratio. The technique is apparently used with
> automotive racing engines to fine tune the air fuel mixture to
> optimize power output.
> Does anyone know if that concept and equipment has been applied to an
> OBAM aircraft?
> It sounds like an interesting and plausible concept.
> Stan Sutterfield
> Reno Race 84
An engine guru explained the O2 sensor to me
at OSH a few years back. It response to the
presence of any oxygen in the exhaust gas stream
and unless fitted with an electrical heater,
doesn't give out useful information until it's
warmed up by the exhaust.
The output voltage is a function of oxygen
concentration . . . so any mixture running
lean will use up all the fuel with oxygen
left over . . . hence some voltage will
be generated. Stoichiometric mixture will
produce zero volts . . . mixture richer
than stoichiometric will also produce zero
volts.
These sensors have been used on OBAM aircraft
for many years. Contrary to popular myth, leaded
fuel doesn't seem to 'clog them up' . . . I've
met two pilots flying them in 100LL fueled aircraft
with useful performance. In both cases, adjusting
mixture for xx.x millivolts on a display produced
an accurate and repeatable setting of 'xx degress
lean of peak' . . .
The agile fuel injection computer can be fitted
with mathematical smarts to extrapolate injector
timing for performance goals on the rich side of
stoichiometric.
The output voltage is, as I recall, small . . .
tens of millivolts. Useful application usually
calls for some active signal conditioning
for presentation on a display.
The short answer is, "Yes, an automotive O2
sensor can be a significant component of your
operating design goals.
Bob . . .
*
*
|
| | - The Matronics AeroElectric-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
|
|
|
| Back to top |
|
|
|
|
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum
|
Powered by phpBB © 2001, 2005 phpBB Group
|
Get Email Distribution Too!
FAQ
Search
Memberlist
Usergroups
Register
Profile
Log in to check your private messages
Log in
