WBO2 sensor location
Discussion
I need some advice on were to fit a WBO2 sensor on a Rover V8 in a kitcar.
The exhaust system is 4-1 on either bank, no cross-over. Do iI fit the sensor on one bank in the collector were the 4 primaries come together. The primaries are about 90cm (3ft) long in average.
Or would it be better to weld some bungs in # 1, 2, 5 and 6 straight after the head and swap the sensor about?
I want to use it for initial tuning and later monitoring.
The sensor will be a Bosch LSU4 type.
The exhaust system is 4-1 on either bank, no cross-over. Do iI fit the sensor on one bank in the collector were the 4 primaries come together. The primaries are about 90cm (3ft) long in average.
Or would it be better to weld some bungs in # 1, 2, 5 and 6 straight after the head and swap the sensor about?
I want to use it for initial tuning and later monitoring.
The sensor will be a Bosch LSU4 type.
I'm running mine in the collector. Ive got a bung on either side, but havn't actually got round to trying on the otherside as ive got a narrow band in that side with a lm3914 led bargraph (pre wide band setup).
Just make sure you dont have any air leaks where your collector joins the rest of the exhaust, as it will make your readings wrong.
Just make sure you dont have any air leaks where your collector joins the rest of the exhaust, as it will make your readings wrong.
pitsnow said:Does this mean it'll be connected to a monitor/display but not used by the ECU for real time fuelling adjustments?
I want to use it for initial tuning and later monitoring.
I think it would be preferable to have the sensor(s) covering all cylinders. This way it'll pick up any lean cylinder or misfire. Lambda per cylinder would be more sophisticated if you have individual cylinder trimming but that seems unlikely.
Id just stick it in the collector where the 4 meet on one side.
IMO it isnt really necessary to use 2, or indeed more sensors, unless you are really going nuts searching for every last ounce of power. But if you were doing that, you would be running mixtures very close to lean anyway, which again isnt very sensible if wanting a reliable road engine.
If you are running an injection system then its very unlikely you will get much of a variance between cylinders. Run a safe rich mixture overall, and it would be ok. Trying to edge leaner to get a few more hp isnt worth it. ( I did that, and melted a piston eventually )
I just ran my old engine with a sensor after the pass side turbocharger.
As already stated, just make sure there are no air leaks anywhere in the manifold, as that will give falsely rich readings. ( i think its rich anyway... )
IMO it isnt really necessary to use 2, or indeed more sensors, unless you are really going nuts searching for every last ounce of power. But if you were doing that, you would be running mixtures very close to lean anyway, which again isnt very sensible if wanting a reliable road engine.
If you are running an injection system then its very unlikely you will get much of a variance between cylinders. Run a safe rich mixture overall, and it would be ok. Trying to edge leaner to get a few more hp isnt worth it. ( I did that, and melted a piston eventually )
I just ran my old engine with a sensor after the pass side turbocharger.
As already stated, just make sure there are no air leaks anywhere in the manifold, as that will give falsely rich readings. ( i think its rich anyway... )
Eliot
If there are air leaks after the sensor, I would assume they do not interfere with the measurement?
My exhaust system does have some minor leaks after the collector, going into the side pipes.
GreenV8S
Sophisticated and Rover V8 are not words I would normally use in the same sentence.
This kitcar of mine is a track tool with road use to drive to and from. Brute force is more an issue than sophistication.
The WBO2 will be part of the VEMS gen 3.2 controller set-up. The sensor will always provide information to the controller.
Stevie
I agree, it will be saver to run the engine on the richer side.
My initial aim will be high 14 for cruising and 13 for part throttle acceleration and probably high 12 for all out WOT. Anyone have some comments on that?
As to the air leak and sensor false measurements, it would be lean would it not?
The sensor would see oxygen surplus which is lean.
I am sure someone will correct me if wrong.
If there are air leaks after the sensor, I would assume they do not interfere with the measurement?
My exhaust system does have some minor leaks after the collector, going into the side pipes.
GreenV8S
Sophisticated and Rover V8 are not words I would normally use in the same sentence.
This kitcar of mine is a track tool with road use to drive to and from. Brute force is more an issue than sophistication.
The WBO2 will be part of the VEMS gen 3.2 controller set-up. The sensor will always provide information to the controller.
Stevie
I agree, it will be saver to run the engine on the richer side.
My initial aim will be high 14 for cruising and 13 for part throttle acceleration and probably high 12 for all out WOT. Anyone have some comments on that?
As to the air leak and sensor false measurements, it would be lean would it not?
The sensor would see oxygen surplus which is lean.
I am sure someone will correct me if wrong.
I am pretty sure air leaks will give a falsely rich reading.
I had most of my part throttle at 14.7:1 where it would let me.
60-90mph cruise was closer to 15.5:1, and full power I had mine at around 12.0:1 AFR, which on a turbocharged engine is ok, but a touch lean. It did go to about12.5:1 at times, though usually not under sustained load.
11.5:1 AFR would be safer for a forced induction motor
If you are running n/a, then high 12's maybe even touching 13.0:1 for WOT mixture would be ok.
I had most of my part throttle at 14.7:1 where it would let me.
60-90mph cruise was closer to 15.5:1, and full power I had mine at around 12.0:1 AFR, which on a turbocharged engine is ok, but a touch lean. It did go to about12.5:1 at times, though usually not under sustained load.
11.5:1 AFR would be safer for a forced induction motor
If you are running n/a, then high 12's maybe even touching 13.0:1 for WOT mixture would be ok.
pitsnow said:
As to the air leak and sensor false measurements, it would be lean would it not?
The sensor would see oxygen surplus which is lean.
I am sure someone will correct me if wrong.
I agree, excess oxygen in the exhaust is interpreted as lean. Even if it comes from a misfire from a very rich engine. Which can be embarassing if the misfire is caused by over fuelling.
If the engine ECU is sophicated enough to vary individual cylinders then a bung in every pipe would be well worth it. As most Rover manifolds certainly don't provide the same amount of air to each cylinder, even if the ECU doesn't have this capability you can improve things by swapping injectors around, as their flows tend to vary by 4-5%, if not more.
The main / std mixture measurement point is in the collector or just after it
Matt
The main / std mixture measurement point is in the collector or just after it
Matt
Gassing Station | Engines & Drivetrain | Top of Page | What's New | My Stuff