Idle curiosity of the AFR kind!
Discussion
Bit of expert advice for a numpty wanted...
If....I wanted to fit an AFR (Air/Fuel ratio) gauge for my LS7, how would I go about it?
The Lamdas that come with the loom/ECU are they wide-band? (wouldn't know one from a sheep!)
Since these connect into the ECU Loom, how would one connect such a guage when there is no 'out' from the ECU???
All probably silly questions, but then... I am bored!
On a footnote, and putting two & two together, I suspect that there is no need to fit a speedo sensor (which connects to the ECU loom) if you are using a dash system with its own? TRUE or FALSE?
cheers
Keith
If....I wanted to fit an AFR (Air/Fuel ratio) gauge for my LS7, how would I go about it?
The Lamdas that come with the loom/ECU are they wide-band? (wouldn't know one from a sheep!)
Since these connect into the ECU Loom, how would one connect such a guage when there is no 'out' from the ECU???
All probably silly questions, but then... I am bored!
On a footnote, and putting two & two together, I suspect that there is no need to fit a speedo sensor (which connects to the ECU loom) if you are using a dash system with its own? TRUE or FALSE?
cheers
Keith
I have fitted the innovate motorsports lambdas and they use the BOSCH wideband sensors that are feeding some sort of controller, that then provides
a voltage that is related to the AFR/Lambda value. I would assume that the lambda sensors are directly connected to the ECU via the loom. I would assume that these are BOSCH or similar lambda sensors. They typicall have 4 wire, 2 for heating 2 for signal.
I would say the easiest way is over the OBDII interface, that should give you the AFR reading. I am sure that if there is software that can read out the AFR then you should also be able to find AFR gauges that can interface with the OBDII,
just googled there you are http://www.ot-2.com/
a voltage that is related to the AFR/Lambda value. I would assume that the lambda sensors are directly connected to the ECU via the loom. I would assume that these are BOSCH or similar lambda sensors. They typicall have 4 wire, 2 for heating 2 for signal.
I would say the easiest way is over the OBDII interface, that should give you the AFR reading. I am sure that if there is software that can read out the AFR then you should also be able to find AFR gauges that can interface with the OBDII,
just googled there you are http://www.ot-2.com/
Which begs the following questions:
1. Are the Lambda sensors that JS supplied with the LS7 engine wideband??? These connect directly via the engine loom to the ECU.
2. If not, how would I (or should I) connect such wideband units to the ECU as a replacement?
2. If I wanted to use a proper dash gauge, which one should I use, and presumably it will connect to the OBDII..or???
cheers
Keith
1. Are the Lambda sensors that JS supplied with the LS7 engine wideband??? These connect directly via the engine loom to the ECU.
2. If not, how would I (or should I) connect such wideband units to the ECU as a replacement?
2. If I wanted to use a proper dash gauge, which one should I use, and presumably it will connect to the OBDII..or???
cheers
Keith
i use Tech Edge La1 from this site..http://www.wbo2.com/la1/default.htm
However Ive gone this route as i dont have Odb connections... if you do, you can tap into the wiring and run a gauge off it..
most lamba are Bosch and are narrow band if standard system...wideband sensors are 3 times the price.
p.s. make sure you get the right sensor as it will alter your figures and Fuel mixture
Dom
However Ive gone this route as i dont have Odb connections... if you do, you can tap into the wiring and run a gauge off it..
most lamba are Bosch and are narrow band if standard system...wideband sensors are 3 times the price.
p.s. make sure you get the right sensor as it will alter your figures and Fuel mixture
Dom
Hi
If you are running a standard GM ECU as you are they will be narrow band O2 sensors..... the GM ecu uses a funny language so i doubt its possible to convert that to any meaningful data ie 14.7 to 1 etc but it may be possible search LS1tech.com
As Spatz says you can fit a wideband into your header/collector as a few guys have done and that will be able to give you the data you want on a fancy little guage. Innovate do some nice units that can incorporate everything you need. What do you want one for? just datalogue
If you are running a standard GM ECU as you are they will be narrow band O2 sensors..... the GM ecu uses a funny language so i doubt its possible to convert that to any meaningful data ie 14.7 to 1 etc but it may be possible search LS1tech.com
As Spatz says you can fit a wideband into your header/collector as a few guys have done and that will be able to give you the data you want on a fancy little guage. Innovate do some nice units that can incorporate everything you need. What do you want one for? just datalogue
As said the existing sensors are likely narrow band and will be no use to you even if you could access the data from your ECU. Narrow band just switch at 14.7 so can only indicate you are running richer or leaner than 14.7 but are unable to tell you by how much.
The simple route is to weld another sensor port in the exhaust and fit one of the many aftermarket wideband systems. I run Innovate but there are many others as good.
Steve
The simple route is to weld another sensor port in the exhaust and fit one of the many aftermarket wideband systems. I run Innovate but there are many others as good.
Steve
widebands only differ from narrow band in FUNCTION, that they are able to measure the higher rev range above 4000rpm much more ACURATELY because their responsetime is shorter.
There is no need for much acurate PID going on in the higher rev range in an ECU anyway, specially if you're looking for power not emission euro4 or higher standard.
So what's the point of using one.
But the main question is:
Why do you want this on your dash? the display could never keep up with the speed of the wideband probe. Your mind wouldn't be able to keep up with a narrowband information.
No offence, but how would you interpret the outcome of the display?
I wouldn't know what to do with the info while driving. It would only be interesting during ECU programming, but as said the display would be way to slow to be useable during dyno.
If you want to see if somethings wrong, there are way better methods of noticing.
If it is a gadget, go and take whatever you like to spend. (the engine management only needs narrowband to run right)
There is no need for much acurate PID going on in the higher rev range in an ECU anyway, specially if you're looking for power not emission euro4 or higher standard.
So what's the point of using one.
But the main question is:
Why do you want this on your dash? the display could never keep up with the speed of the wideband probe. Your mind wouldn't be able to keep up with a narrowband information.
No offence, but how would you interpret the outcome of the display?
I wouldn't know what to do with the info while driving. It would only be interesting during ECU programming, but as said the display would be way to slow to be useable during dyno.
If you want to see if somethings wrong, there are way better methods of noticing.
If it is a gadget, go and take whatever you like to spend. (the engine management only needs narrowband to run right)
harry b said:
widebands only differ from narrow band in FUNCTION, that they are able to measure the higher rev range above 4000rpm much more ACURATELY because their responsetime is shorter.
There is no need for much acurate PID going on in the higher rev range in an ECU anyway, specially if you're looking for power not emission euro4 or higher standard.
So what's the point of using one.
I would say that statement is not right. A narrowband sensor will jump from 0 to 5V (example) whenever it detects Lambda 1,0( AFR 14)so the ECU only knows the exhaust gas is below or above this value. A wideband sensor however will give you linear ramps from 0,5 to 1,5 lambda. I have the innovate motorsports installedThere is no need for much acurate PID going on in the higher rev range in an ECU anyway, specially if you're looking for power not emission euro4 or higher standard.
So what's the point of using one.
and am very happy with my readouts, very helpful when tuning the map while driving.
I wonder how you map the engine with no meter at all......?
I understand that lambda sensors are used when you map the engine on a dyno, or what are they using ?
My innovate does not give the impression to be behind, more like real time, and when I change the injection time
I can see immediately the change on the AFR reading.
Just came back from playing with my engine as I am working also on idle and cold start behaviour.
When I change from 1,8 ms to 1,85 ms injector opening time I can see an immediate change on the meter (not a big one like going from 0,91 to 0,95) when I engage closed loop I can also see the meter moving very quickly to the Lambda 1 only that the Idle at lambda 1 is not the nicest one......
I understand that lambda sensors are used when you map the engine on a dyno, or what are they using ?
My innovate does not give the impression to be behind, more like real time, and when I change the injection time
I can see immediately the change on the AFR reading.
Just came back from playing with my engine as I am working also on idle and cold start behaviour.
When I change from 1,8 ms to 1,85 ms injector opening time I can see an immediate change on the meter (not a big one like going from 0,91 to 0,95) when I engage closed loop I can also see the meter moving very quickly to the Lambda 1 only that the Idle at lambda 1 is not the nicest one......
Edited by spatz on Thursday 30th September 15:16
Hi
Erm, my 2pence, for what its worth...
I have done a lot of dyno work on 4st race bike engines, a lot of these have narrow band Lambda's, and we generate an AFR graph from the narrow band lambda's at times (although the Dyno has a gas analyser as well). The do not only give an output only at ideal AFR, they do give an analogue output, but only over a narrow band. (sorry to contradict you Harry :-) )
This subject is exhaustive, but the fact of the matter is, that a 4st engine is really, really not fussy with respect to either fuelling or ignition. Have a look at an injected 2st fuel/ignition map and you will see what I mean. (big changes in 10 rpm steps)
You can make relatively large changes (2or 3 %)and see no difference on a 4st. A big lazy us v8 will be even less fussy.
This is why most cars, even high performance cars, do not have an AFR sensor for each cylinder, the reason is that the added complication of trimming each cylinder just makes such a small difference that it is not worth doing.
In summary, fuelling on a 4st injected engine is more about swaying the fuelling this way or that rather than absolute precise fuelling. This is also evident in 'emissions' tunes, where the fuelling / ignition has been altered to pass the test. Does this make the engine unsafe? no. Does it make it inefficient? no. Does it make a huge difference in power delivery? not really (although gains over stock maps can be had for different reasons).
When we want to do a quick back to back test we have used high level professional test riders with an AFR gauge on the dash, and you know what? the comments from the riders are remarkably close to the logged data.
If you want to have a gauge on your dash then go for it! How much useful information will you get? well that can be argued all day, however if there is something seriously wrong, then the gauge will help - and lets face it, it does not take a lot for it all to go seriously wrong - MAF, Lambda....
I have a Bosch datasheet on the two types of wideband's available, if anyone is interested.
;-)
Gareth
Erm, my 2pence, for what its worth...
I have done a lot of dyno work on 4st race bike engines, a lot of these have narrow band Lambda's, and we generate an AFR graph from the narrow band lambda's at times (although the Dyno has a gas analyser as well). The do not only give an output only at ideal AFR, they do give an analogue output, but only over a narrow band. (sorry to contradict you Harry :-) )
This subject is exhaustive, but the fact of the matter is, that a 4st engine is really, really not fussy with respect to either fuelling or ignition. Have a look at an injected 2st fuel/ignition map and you will see what I mean. (big changes in 10 rpm steps)
You can make relatively large changes (2or 3 %)and see no difference on a 4st. A big lazy us v8 will be even less fussy.
This is why most cars, even high performance cars, do not have an AFR sensor for each cylinder, the reason is that the added complication of trimming each cylinder just makes such a small difference that it is not worth doing.
In summary, fuelling on a 4st injected engine is more about swaying the fuelling this way or that rather than absolute precise fuelling. This is also evident in 'emissions' tunes, where the fuelling / ignition has been altered to pass the test. Does this make the engine unsafe? no. Does it make it inefficient? no. Does it make a huge difference in power delivery? not really (although gains over stock maps can be had for different reasons).
When we want to do a quick back to back test we have used high level professional test riders with an AFR gauge on the dash, and you know what? the comments from the riders are remarkably close to the logged data.
If you want to have a gauge on your dash then go for it! How much useful information will you get? well that can be argued all day, however if there is something seriously wrong, then the gauge will help - and lets face it, it does not take a lot for it all to go seriously wrong - MAF, Lambda....
I have a Bosch datasheet on the two types of wideband's available, if anyone is interested.
;-)
Gareth
spatz said:
I wonder how you map the engine with no meter at all......?
Arrghhhh. (hitting my head on the desk) Only one answer: How did we do it in the 70's???Edited by spatz on Thursday 30th September 15:16
That's where I come from. We had main jets, mixture jets, small drills, small counterweights and even smaller springs to do it with.
Offcourse I use a narrowband lambda now, no need for a wideband to get the performance you want or the need to view it. By the way, I put an EGT in the car, much better for reading, and it tells me much more than any AFR. you see when something bad is going to happen soon, if you don't change anything soon.
I think you tell the same things Garreth, those lumps don't need acurate fueling to run right, so why a WIDE band in stead of a NARROW band. Don't remind me about 2strokes (I had a Wartburg) and a guy close to me still races a Trabant. RIiiingdingding ding ding....... Nightmares and sleepless nights.
Hi
How did we do it in the 70's
Answer is simple - we didn't!
You had to re-jet for different altitudes, and in racing conditions re-jet for different atmospheric pressures and humidity from one race to the next (note how few blow ups happen now compared to the good old days - yes engineering is much better now, but the primary reason was leaning off a highly strung engine just a little too much). Then you would spend hours and hours trying to expand the envelope of compromise that is the carburettor.
We take it for granted now that you can drive your high performance car up a mountain and it still runs okay. (anyone remember what happened to your tuned carb engine when you drove over a mountain? cough cough splutter!) I certainly do!
Old low performance cars just ran rich from the factory, that was deemed to be safe for most conditions. Cars intended for different markets had different jetting. Remember looking at the colour of your exhaust or spark plugs and tweaking the air screw accordingly? I do! :-) Aaagh those days were great - when your mates mate would 'tune' your engine by ear and was the local hero for it!
Narrow Band vs. Wide Band? Well an engine runs out of the 'normal' band quite a lot - deceleration, hitting the gas (pumper type effect) etc etc. In the past you were just 'feeling' how the engine performed under these conditions and adjusted accordingly, but with the wide band we can see a lot more information of this 'out of band' area. i.e. An engine is not always at constant throttle, in fact it is more at varying throttle than constant throttle.
Imagine a 'narrow band temperature gauge' vs. a 'wide band temperature gauge' ... the narrow band type would, say, start at 82degC and end at 87degC. Helpful, yes! but there is a lot of useful information that you are missing out on, such as knowing that taking it over 110degC is dangerous (if that were the case). A 'wide band' temp gauge would read as most temp gauge now read 40ish to 120ish...
I apologise profusely in advance if I am teaching you to, erm, suck the proverbial egg ;-)
Aaagh, Fridays! don't you love 'em? Loads to do, people around me are stressing, and all I can think of is what I am going to next on the Ultima tomorrow :-)
Gareth
How did we do it in the 70's
Answer is simple - we didn't!
You had to re-jet for different altitudes, and in racing conditions re-jet for different atmospheric pressures and humidity from one race to the next (note how few blow ups happen now compared to the good old days - yes engineering is much better now, but the primary reason was leaning off a highly strung engine just a little too much). Then you would spend hours and hours trying to expand the envelope of compromise that is the carburettor.
We take it for granted now that you can drive your high performance car up a mountain and it still runs okay. (anyone remember what happened to your tuned carb engine when you drove over a mountain? cough cough splutter!) I certainly do!
Old low performance cars just ran rich from the factory, that was deemed to be safe for most conditions. Cars intended for different markets had different jetting. Remember looking at the colour of your exhaust or spark plugs and tweaking the air screw accordingly? I do! :-) Aaagh those days were great - when your mates mate would 'tune' your engine by ear and was the local hero for it!
Narrow Band vs. Wide Band? Well an engine runs out of the 'normal' band quite a lot - deceleration, hitting the gas (pumper type effect) etc etc. In the past you were just 'feeling' how the engine performed under these conditions and adjusted accordingly, but with the wide band we can see a lot more information of this 'out of band' area. i.e. An engine is not always at constant throttle, in fact it is more at varying throttle than constant throttle.
Imagine a 'narrow band temperature gauge' vs. a 'wide band temperature gauge' ... the narrow band type would, say, start at 82degC and end at 87degC. Helpful, yes! but there is a lot of useful information that you are missing out on, such as knowing that taking it over 110degC is dangerous (if that were the case). A 'wide band' temp gauge would read as most temp gauge now read 40ish to 120ish...
I apologise profusely in advance if I am teaching you to, erm, suck the proverbial egg ;-)
Aaagh, Fridays! don't you love 'em? Loads to do, people around me are stressing, and all I can think of is what I am going to next on the Ultima tomorrow :-)
Gareth
GarethGTR said:
Aaagh, Fridays! don't you love 'em? Loads to do, people around me are stressing, and all I can think of is what I am going to next on the Ultima tomorrow :-)
Gareth
You and me both! - Can't wait...problem is the missus has other ideas! She uses the quivering bottom lip and pleading eyes for an outing saturday to Bath! What's this with women and Bath? Gareth
OK, a few different shops, but more and more that same national ones are taking over!
- Spose I could plead poverty! - but then I don't have much of a chance there, cos the 'seat-cover' (Jeez that's an old saying now!)has taken to rushing to the window when I pull up from work to 'clock' what other parcels I might be squirreling away in the garage! Don't you just love them!
...oh! ..and I did for the first time EVER...forget our wedding anniversary yesterday!
(OMG!) ... the worrying thing was she just said 'it doesn't matter'....errr what does THAT mean!
Keith
Edited by V8 Vum on Friday 1st October 14:19
ok updateds on the mapping, the AFR sensor is no good help for fast changing situations, it is a great help for constant RPMs and idling but for acceleration not
giving any reliable data. I have played with the map for hard accelerations and increased the amount of fuel slightly but the results were poor. So i went back to the original map but kept the values around idle and very low rpms to avoid kangarooing riding around the town, which is now working great.
I wonder if you can simulate all the road situations on a dyno and how you actually map the car to the optimium (maximum HP/torque)
Not that I am not happy what I have but there are some situations where I can tell it is not perfect. Mainly very hard acceleration.
giving any reliable data. I have played with the map for hard accelerations and increased the amount of fuel slightly but the results were poor. So i went back to the original map but kept the values around idle and very low rpms to avoid kangarooing riding around the town, which is now working great.
I wonder if you can simulate all the road situations on a dyno and how you actually map the car to the optimium (maximum HP/torque)
Not that I am not happy what I have but there are some situations where I can tell it is not perfect. Mainly very hard acceleration.
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