Recommendations on wideband lambda systems

[Nick B.]

I am on the lookout for a wideband system to provide me with a bit of information on my carburation. 

 

What should I get, that works well with a megajolted car?

 

I am tempte to go with the techedge kit from triggerwheels, but have not really got a clue

 

Any suggestions?

 

Cheers

Nick

[Nick Jones]

Tech Edge have a good reputation.  I have no experience with them though.  I've always used Innovate (LC1).  Had two systems, one on the Vitesse which has been working 10 years now and one on the PI (dunno if that is still working).  Innovate got a bad rep early on as the analogue outputs were fragile and easy to fry.  That issue was fixed even before I got my first one though.....

Quite a few out there now

https://www.plxdevices.com/PLX-Wideband-O2-Air-Fuel-Ratio-Sensor-Modules-Gauges-s/125.htm

https://www.14point7.com/pages/products

Nick

[oldtuckunder]

My only input would be if you can find a system that you can datalog, whilst its nice having another gauge to look at whilst pootling along, and its good for setting up idle mixtures etc, what you will find (unless you have a willing helper in the passenger seat who doesn't get frightened) that all the interesting points you would love to know what your AFR's are, you are concentrating far too much on driving the car to take a look at a gauge, also at my age 20 mins later you cant quite remember what the numbers were anyway.

The ability to do a test drive, and replay it later, and also compare with previous run is very valuable.

Of course then you find out that you also want to datalog other info.........

I'm running an Innovate LM2 that has dual sensors, data logging and multiple other inputs with my recently Megajolted Vitesse.  My hope had been to share some of the inputs I had previously datalogged to the LM2 with the MJ and the LM2, like TPS, RPM, MAP which are now hooked up to the MJ. However the LM2 had developed a board fault and needs to go back to the USA to be fixed, so at the moment all the LM2 is doing is running and logging the twin sensor AFR's.

I'm not sure about other Innovate kit, but I would advise against an LM2, its a brilliant concept and has worked well for a few years, but its all a tad fragile, Innovate support isn't brilliant, and since they killed all the Innovate Forums, where all the real expertise/advise was (plus a huge amount of slagging off Innovate, which is why they killed it) its hard to get any advice.

Alan

[spitfire6]

Hi,

 I can't recommend Innovate LC1 or LC2. as mine both use the Bosch™ LSU4.2 Sensor. The sensor requires free air calibration and both did not last long.

I use the AEM 30-4110 that utilises the superior Bosch™ LSU4.9 Sensor, that does not require free air calibration and will last much longer.

The AEM comes with a gauge. An analogue output that is connected to my ECU for feedback. There is also a serial output to log results with Hyperterminal™ or similar.

The AEM was recommended on here and I also recommend it.

Cheers,

Iain.

 

[dggt6]

Have you looked at the 14Point7 range of "EFI" products?

The original version of the Spartan sensor is still in my GT6 and I think it is one component that has NOT given me trouble!!!!

Alan was very helpful in fixing my mistake with  his product.

 

Cheers,
Doug

[spitfire6]

Hi,

 Whatever you buy. Buy one with a Bosch™ LSU4.9 Sensor. Not a cheap 4.2.

Cheers,

Iain.

[Nick Jones]

As mentioned above my original LC-1 (with 4.2 sensor I think) has been in place more than 10 years - maybe 40k.  It's still fine.

Nick

[spitfire6]

Hi,

 If you have a 4.2 and its working; Happy days.

The 4.2 is used in many cars without problem. The 4.9 is used in many more with less problems. The 4.2 is used in a lot of aftermarket combos, as it is older and cheaper. If you buy a new sensor/combo; Avoid the 4.2.

Cheers,

Iain.

[Nick B.]

Thank you for all the valuable information. Still quite difficult for me to find out what is what here.

Is it possible to use the Megajolt unit for calibration. How do I combine the two datasources ?

Well first thing is to just go ahead and fit a sensor to the exhaust :-)

 

Cheers

Nick

 

[oldtuckunder]

Hi 

No you can't use MegaJolt to calibrate, in fact the only thing you could use MJ for was to datalog an input voltage signal from something else that was controlling the sensor, and only then if it has an analog output, and you have V4 or above MJ with Aux input that you can feed the AFR voltage signal to. To be honest may not be worth the bother.

I started with an Innovate Datalogger that also controlled wideband sensors, so I could datalog everything in one trace. I then added MJ which has stolen my TPS, MAP and RPM inputs, hoping I may find a way to share them so I get data logging back in one place (but LM2 needs a repair before I find that out) I know I could datalog from the MJ but that requires a connected laptop (not practical in competition) and it still wouldn't have AFR's which only go to the LM2.

If I was starting again I do it differently, I started with an expensive(ish) datalogger with wideband, and then added MJ, whereas you have MJ and would like to add wideband.

With hindsight I'd have gone Megasquirt or some other full ECU that would run Ignition Timing, would have TPS and MAP inputs, would control a wideband sensor, and datalog the whole lot together, even though I knew I was unlikely ever to go EFI. I think cost wise in the end it would have been no more expensive, although the majority of the cost would be upfront rather than staged.

Given where you are, although I initially just dismissed it. A good wideband controller and gauge, that has an analog output, hooked up to the aux input of MJ would give you the ability to log, RPM, Ignition Advance, (TPS or MAP depending on which version of MJ you have) and AFR, which would give you a fair amount of tuning data to work with.

Alan 

 

 

[Triumph-V8]

AFR only makes sense in combination with rpm and vacuum or tps signal.

Megajolt has both rpm and vacuum to set ignition timing.

It would be interesting to log the afr with it, anyway it does not help

that much because there is no mapping in Megajolt to find the fuel amount.

It will need some interpretation to translate the logged data to a SU carb or a WBER DCOE.

 

[oldtuckunder]

Actually I found that initially logging AFR with just RPM was incredibly useful and allowed me to resolve a lot of initial carb problems, if your doing repeat test runs the rpm trace tells you where you were at each step, you can even spot the gear changes etc.  Adding TPS gave me more as then I could also see what I was asking for, and then adding MAP which gave me an idea of what was actually happening in the manifold.   As I'm using CD carbs finding out the fuel amount I haven't found a need for, as basically if the MAP is where I expect, and the AFR's are what I desire, then I know that the carbs are delivering the correct amount of fuel, even though I have no idea what that amount is.  The Holy Grail of SU & Stromberg carb logging is measuring piston lift, There are some naff stick in the piston solutions, but they are no good at the extremes which is where you really want to know, plus the fact that you have to remove the damper to use them which defeats half the control in a CD carb.  I did actually manage to build a cludgy probe driven logger that would work with a sealed Stromberg, right at the time I switched to 1.75CD's and solved my high rpm problems, so haven't gone back to trying to improve it. My goal was always to have something permanent, as I normally find the most interesting things come from looking at logs post event, not from controlled tests.

Alan

[Nick B.]

Thanks for more good advise.  Perhaps it is a good idea to enlightned you on why I want to monitor AFR.

 

I have endless  some problems with my oilpressure and oiltemperature. When I flog the car I end up with almost no pressure at idle, and very hot oil (around 125 degrees)

I took out the shells last thursday, and there were no obvious damage, they were actually very spotless and unworn after 10.000 miles since rebuild (including 10CR). I changed the oilpump, even though the existing were with good tolerances.

The 1300 engine has raised compression, and 1.5 SU, with ported head. Needles are AAA emergency needles which are the richest I could find.

Now clever people suggest that I am running to lean, making the engine way to hot (melted sparkplugs would suggest this claim has something to it). Besides my ignition is probably off to, since I have not managed to start the megajolt. The generator fried the MJ-board instantly the last time, so I need a new generator (less lucas india powerspikes)

So I am diagnosing the AFR to get the correct mixture for this engine, as it is so modified I cannot go by book.

 

I am tempted by the PLX device, which has an analog output, and I obvously does not need the output for anything else than monitoring and adjust the MJ-ignition table after test runs.

 

First thing I do is to get the mad welder to help me putting a bung into the exhaust.

 

Cheers

Nick

 

 

 

[oldtuckunder]

2 hours ago, Nick B. said:

Now clever people suggest that I am running to lean, making the engine way to hot (melted sparkplugs would suggest this claim has something to it). Besides my ignition is probably off to, since I have not managed to start the megajolt. The generator fried the MJ-board instantly the last time, so I need a new generator (less lucas india powerspikes)

So I am diagnosing the AFR to get the correct mixture for this engine, as it is so modified I cannot go by book.

 

I am tempted by the PLX device, which has an analog output, and I obvously does not need the output for anything else than monitoring and adjust the MJ-ignition table after test runs.

 

First thing I do is to get the mad welder to help me putting a bung into the exhaust.

 

MJ and the tailored further advance in the mid range I think is making my engine run about 10 deg cooler, at high rpms it shouldn't make much difference unless your current mechanical advance is way out of spec, have you checked it?

Had a quick look at the PLX devices, and the GEN-4 ones look to be a nice spec with an intelligent controller. A lot of after market ones don't and basically just power up the sensor, its that that actually kills the sensors quickly.  NB I know nothing about the PLX devices, but from a quick read if I was looking for a change I would look further at them.

As bungs and plugs are cheap, one thing I might do if I was buying a device that only supported one sensor, is to have several bungs welded into the exhaust.  I actually run a twin sensor system, so have a bung & sensor in each exhaust manifold branch, so I can actually monitor each carb individually, ideal for setting up, and ensuring that they are in sync with each other throughout the rpm/load range.  However even with only one sensor if you have the bungs somewhere sensible you could do the same thing by just swapping the sensor between different bung positions. Once you are happy that both carbs are in sync, then a bung further back in the exhaust that measures the combined output would be fine for monitoring.  If your fitting bungs close towards the engine I'd advise getting either the longer bungs so the sensor isn't so exposed, or the extender bungs that screw in between the bung and the sensor to do the same thing (but make sure you don't buy the CAT cheater extenders that have a tiny hole in them, as they basically stop the sensor doing much "which is what they were designed to do).

A;an

[Nick Jones]

Running lean with AAA needles would be a surprise......... they are really rich - do you know which springs you have fitted?  My 1300 Herald in it's fiercest state of tune (maybe 100 bhp) used those for a while.  Did about 15mpg and turned the back of the car black.....  Ended up with AAT or AAT I think.

Also, high oil temperatures with a small crank (I assume?) 1300 are not usually a problem.  I assume no oil cooler fitted?  I actually took the oil cooler off my Herald after the 1300 was fitted (was previously had a 1500 which really did need the cooler) because the oil stat never seemed to open.

Do you have high water temps also?  Could be that either the rad is not flowing very well or the water pump housing is corroded internally so that the housing -> impellor gaps are too large, spoiling the pumps efficiency.  Retarded ignition (including no vacuum advance function) can contribute to this by causing generally hotter running,

Melted plugs..... scary!  Could be due to wrong heat range ( should be at least BP6ES maybe even BP7ES in NGK speak), pre-ignition due to excessive chamber temperatures caused by over heating, or detonation.  The last of these could be due to excessive CR, poor fuel, lean running, over-advanced timing or, occasionally, high chamber temperatures.  You should be most worried about this one as detonation kills pistons really quickly.......

Nick

 

[Nick B.]

22 minutes ago, Nick Jones said:

Running lean with AAA needles would be a surprise......... they are really rich - do you know which springs you have fitted?  My 1300 Herald in it's fiercest state of tune (maybe 100 bhp) used those for a while.  Did about 15mpg and turned the back of the car black.....  Ended up with AAT or AAT I think.

Also, high oil temperatures with a small crank (I assume?) 1300 are not usually a problem.  I assume no oil cooler fitted?  I actually took the oil cooler off my Herald after the 1300 was fitted (was previously had a 1500 which really did need the cooler) because the oil stat never seemed to open.

Do you have high water temps also?  Could be that either the rad is not flowing very well or the water pump housing is corroded internally so that the housing -> impellor gaps are too large, spoiling the pumps efficiency.  Retarded ignition (including no vacuum advance function) can contribute to this by causing generally hotter running,

Melted plugs..... scary!  Could be due to wrong heat range ( should be at least BP6ES maybe even BP7ES in NGK speak), pre-ignition due to excessive chamber temperatures caused by over heating, or detonation.  The last of these could be due to excessive CR, poor fuel, lean running, over-advanced timing or, occasionally, high chamber temperatures.  You should be most worried about this one as detonation kills pistons really quickly.......

Nick

 

Springs are 'uprated' marked with a yellow dot as far as I recall.

My watertemp is perfect in the middle, even when oil is very hot. My very hot oil is a problem related to going up and down alpine passes (10CR 2017) or prolonged streches of autobahn after my OD went AWOL. 

The melted plug were before I went for AAA needles - that was on AAQ needles. And it was on a trackday in second gear screaming round a bend in way to many RPMs (I did beat that AC Cobra though :-)  )

My bet is that my ignition timing is buggered as I am running an old unit probably with a half way dead vacuum unit) I need to get the MJ sorted.

 

Cheers

Nick

 

 

[oldtuckunder]

1 hour ago, Nick B. said:

 

My bet is that my ignition timing is buggered as I am running an old unit probably with a half way dead vacuum unit) I need to get the MJ sorted.

 

As I think you said your MJ was fried, if you haven't bought a replacement yet, one option might be to look at a Microsquirt unit even though your running carbs. It will do all the MJ ignition stuff, plus it has multiple analog inputs for MAP, TPS etc, plus will take the Wideband output from various controllers like PLX. Then you can datalog everything in one stream. It wont mind that you don't have injectors hooked up, but if you ever wanted to go that route in the future you have most of the work done.

NIck suggested it when I was looking at MJ in the winter, wish now I'd thought harder, and if I'd known that the Innovate LM2 was going to start playing up, I'd have definitely gone that route. Hindsight is only something you get after spending money on something else!

Alan