4 o2 sensors?

1444 Views 15 Replies 6 Participants Last post by oldgixxer, Jan 17, 2017

GSXRMOD750

Discussion Starter · Jan 15, 2017

Does anyone have experience running 4 O2 sensors (1 per cylinder) with a PCV and two 2 channel autotuners?
I'm wondering if the 4 sensors in the headers will impede exhaust flow on yoshi trc exhaust and how to designate/coordinate each sensor with each cylinder/set of injectors?
Any thoughts?

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CrickiKaze

· #2 · Jan 15, 2017

Look at what they have done on cars, some manufactures you can daisy chain and others you would have to run all to a module and 'label' them no matter which one you use. That's a bit of a nightmare since they would all have a controller and not a lot of room pending size of the controller.

Though there maybe an obstruction in the flow for a much smaller diameter pipe(s) I don't think you will notice it.

GSXRMOD750

Discussion Starter · #3 · Jan 15, 2017

Dynojet has plug and play autotune modules that each have 2 o2 sensors. I would need to weld in all the bungs.
The physical installation is very simple but I'm not sure if the PCV already has a way to designate each o2 a specific cylinder. I wouldn't want a particular sensor affecting any of the fuel table's other than the one for the cylinder/injectors it is dedicated to.
Any dynojet experienced guys in here?

oldgixxer

· #4 · Jan 16, 2017

What is your intended goal by doing this?

GSXRMOD750

Discussion Starter · #5 · Jan 16, 2017

oldgixxer said:
What is your intended goal by doing this?

Right now I'm running 6 maps, 1 pear gear. PCV software allows you to run one per gear per cylinder. After the additional sensors are installed I'll be running the max amount of maps for my PCV, so 18 more maps 24 total. Each map has its own trim and fuel tables, this is why the 4 o2's are needed, and will all be running off the same target AFR. Each set of fuel tables has percentage of trottle axis and rpm axis creating 279 tune-able cells per map. I'll be running 24 maps so that is 6,696 tune-able cells that are all completely unique and variable depending on exterior conditions. This will allow my fuel management to be highly optimized vs 1 map for all gears and cylinders that most people run where you only have 279 tune-able cells. Right now I have only 1,674 tune-able cells which is 1 map per gear.

oldgixxer

· #6 · Jan 16, 2017

Sorry I asked. To each their own.

-JK750-

· #7 · Jan 16, 2017

oldgixxer said:
Sorry I asked. To each their own.

:lol

OP must have some serious engine work done to justify all that...

oldgixxer

· #8 · Jan 16, 2017

-JK750- said:
:lol

OP must have some serious engine work done to justify all that...

Dude I bet it's stock.....

-JK750-

· #9 · Jan 16, 2017

oldgixxer said:
Dude I bet it's stock.....

Yeah, I think so too.

Just_Nick

· #10 · Jan 16, 2017

It's really funny, because even the 2,000-2,500 whp Lambos don't bother with such complexity. And you're relying on each O2 sensor being perfectly calibrated, and being able to read properly at that location.

In fact, have you tried calling Bosch and seeing if they even recommend putting their O2 sensors that far upstream? You may end up with sensor failure and inaccurate readings, all for a bike that doesn't need such complexity. I mean, if people can make 500+ whp on motorcycles without it, I know you don't need this mess that you're trying to make for yourself.

-JK750-

· #11 · Jan 16, 2017

2

Nothing wrong doing something like this but you should also be using a Motec or similar to get the tune accurate.

This how the world's top teams have the O2 sensors.

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CrickiKaze

· #12 · Jan 16, 2017

Doesn't matter if its stock or not, tuning each individual cylinder is better if you have the tools and the time.

There is a limit to how far up stream you can put them and its also critical in how/where you place them, such as the images JK provided, putting them on the bottom half of the piping helps to prevent to much heat as strange as that sounds. I have seen shields used to curb the heat if placed on the upper half of the piping.

HeJason

· #13 · Jan 16, 2017

You will gain nothing by tuning each cylinder like that on an inline 4, unless you have issues with your engine and or FI (any performance increase from tuning a bad fuelinjector/cylinder would be negligible to fixing the real issue, which is the FI/cylinder). With a V-twin, yes you will make gains as the header lengths and FI tunings are different as some companies (like HD) tune the rear cylinder richer as it gets less air to prevent over heating. The percentage of a point that each cylinder will be off will not make a difference (unless, as I said before, you have a cylinder with low compression, a low performing fuel injector, ect...). The difference between 12.8 afr and 13.2 is so small that the power difference can be so small that it could be attributed dyno error. Race teams dont use a 500 dollar PCV autotune setups that tune off of O2. You can never get a perfect tune by tuning for AFR alone. They use mutli thousand dollar 4 gas analyzers with data logging. I wouldnt waste the time. :cheers

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Reactions: 1

oldgixxer

· #14 · Jan 17, 2017

CrickiKaze said:
Doesn't matter if its stock or not, tuning each individual cylinder is better if you have the tools and the time.

Bottom line is there is no benefit of doing this. Horsepower and/or ridability wise.
If you really really really need this type of engine management the a dedicated standalone ECU like the $4000 MoTEC would be ideal.

CrickiKaze

· #15 · Jan 17, 2017

oldgixxer said:
Bottom line is there is no benefit of doing this. Horsepower and/or ridability wise.
If you really really really need this type of engine management the a dedicated standalone ECU like the $4000 MoTEC would be ideal.

There is a benefit, how it benefits each individual is different in their capabilities and resources, and yet I can agree with you it would be a waste of time/resorces. There is information that can be gained by doing this and not just for tuning for HP and/or ridability, it has already been brought up about the differences between each injector/cylinder which is already prevalent if they aren't matched
I can tune individual cylinders as is with out buying a $4000 MoTEC system(though not a precise) but I'm not going to do a wideband for each cylinder as it is pointless for me and I'm completely satisfied with the single wideband and current tuner. If someone has the ability to do so with current equipment then what is the issue...

oldgixxer

· #16 · Jan 17, 2017

CrickiKaze said:
There is a benefit, how it benefits each individual is different in their capabilities and resources, and yet I can agree with you it would be a waste of time/resorces. There is information that can be gained by doing this and not just for tuning for HP and/or ridability, it has already been brought up about the differences between each injector/cylinder which is already prevalent if they aren't matched
I can tune individual cylinders as is with out buying a $4000 MoTEC system(though not a precise) but I'm not going to do a wideband for each cylinder as it is pointless for me and I'm completely satisfied with the single wideband and current tuner. If someone has the ability to do so with current equipment then what is the issue...

:thumbup

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