Single System O2 Sensors

[SVTuner]

Sorry if this has been posted before, did a few searches but couldn't find anything.

I'm in the process of building a single turbo LSA (no supercharger) and I was wondering what do I need to change in the software so there is only a single exhaust system. From factory there are two O2 sensors on each bank (pre and post cat) but there will only be a single 4" dump pipe with the rest of the system to follow. Is this something normally done or do most single turbo builders split the system into twin and still use 4 O2's?

[5FDP]

Assuming you will not be running a cat converter anymore because of the turbo, you can just delete those in the tune.

Then you should be able to keep the drivers side o2 sensor where it is because it has to wrap under the vehicle anyway over to the other side (assuming the turbo is on the passenger side), then stick the other o2 sensor before the turbo in the exhaust or the downpipe.

[schpenxel]

I'd try to keep the front O2 sensors and just put them closer to the engine. Factory LS2/3 manifolds have them maybe 8" away from the head (if that).. I'd try to do something like that if possible. Hopefully there is room to put them that close.

[Paz]

Sorry if this has been posted before, did a few searches but couldn't find anything.

I'm in the process of building a single turbo LSA (no supercharger) and I was wondering what do I need to change in the software so there is only a single exhaust system. From factory there are two O2 sensors on each bank (pre and post cat) but there will only be a single 4" dump pipe with the rest of the system to follow. Is this something normally done or do most single turbo builders split the system into twin and still use 4 O2's?

Nope not a lot posted on your problem at all as i have/had the exact same problem and searched for the last couple of months trying to find info with no luck!

I run a single turbo, 4" dump to just behind gearbox then splits into 2x 3" with 2x 3" 100 cell cats and twin 3" the rest of the way.

As Schpenxel mentioned you could try the front O2 sensors in the manifolds pre turbo, you should be able to get one in the drivers side manifold pretty easy and pending vehicle/turbo kit you may get one somewhere in the passenger side (assuming passenger side big single with crossover pipe from drivers side), this should allow you to run Closed Loop i think.

Most just disable the rear O2 sensors in the tune (Post O2 Test and Catalyst).

I have my front two O2 sensors in my dump pipe, i could never get closed loop to work so at this time I'm stuck with Open Loop only, seems to be working though and I'm slowly getting it sorted now.

My thread- http://www.hptuners.com/forum/showth...s-my-open-loop! , may help, may not.

Few more details on your build would be good, plan to be running a maf etc?

[SVTuner]

Hi Paz,
My build is a bit on the different side of things. I'm using the Engine and 6l90E from the VF GTS into a VZ Crewman. I'm going to be using the VZ E38 (originally L76) and a TBM 4L to 6L Converter for the electronic side for transmission control and moulding in the VF shifter for TU/TD. Was going to use the VF loom and E67 ECM but to avoid the horrors of BCM and PIMS conflicts I think the TBM converter will make things a lot easier.

Still undecided about running a MAF, might try both and see how it goes.

I've subscribed to your thread as I think I'll be going back to it later. Going to do the engine swap and sort out any bugs before the turbo goes on.

[Paz]

Sounds like an interesting build SV.

Running a maf may help if you end not being able to run the front O2 sensors and closed loop, biggest issue i am having at the moment with SD open loop is inlet air temps causing it to lean out, I'm adjusting a few tables which seem to be helping but still having issues when it stands still idling for a bit and going lean (lot of underbonnet heat due to turbo).

Good idea on getting used to HP before turbo install, i never did, dived straight into a modded motor with the turbo and it was a steep learning curve, still is

[SVTuner]

Could you relocate the temp sensor to the downstream side outlet of the intercooler? You would avoid a lot of radiant heat having it there.

[Paz]

Into the manifold just behind the throttle body is the answer apparently, I've just got to get myself psyched up to pull the manifold off again lol.

[schpenxel]

Just make sure to set the filter/bias tables up like ZR1's are if you're doing it that way or manifold air temp won't be calculated correctly

[Paz]

I'm running ZR1 settings now Carson.

My inlet air temp is about 3" in front of my throttle body mounted in the bottom of the of the inlet pipe (not ideal i know) and the ZR1 settings have seemed to have help some with the heat soak problems as ar as leaning out.