oscs

iTrader: (19)

I have a 280z with a lq4 swapped in it. It has an ls1 intake,TB,maf sensor with a lq4 computer. I'm about to weld up the bungs for the two O2 sensors and wideband. I'm curious about best placement. One O2 for each bank just after the headers and wideband just after the Y? Does it matter how far back the wideband is on the exhuast? My exhuast doesnt come into the Y until pretty far back into the exhuast.

My next question is tunning. After this is done I will be I listing the help of a good tuner in the greater houston area. I know a couple of people that use HP tuners but I'm not exactly happy about paying $100 just to get access to my computer.... The car is running a tune right now and PCM is unlocked. Should I be looking for an EFI live tuner to save some extra cash on a tune? I'm still very new to gas motors so please bare with me.


Oh and here is the car before I had exhuast put on it.

http://i484.photobucket.com/albums/r...C25B3EFA43.mp4

Sweet_SS

People put them about 6-10" inches from the turbo...if boosted. To close and they will heat up and the reading will be off...too far back and they get to cool. Mine is 6" from the turbo. You could get away with putting it just before the "Y" section.

oscs

iTrader: (19)

I'm assuming your referring to the O2 sensors. What about the wideband? Does that matter how far back? Would it not be more accurate after the Y so it can read both banks?

Sweet_SS

I was referring to the WB. But you could put the 02's relatively close to stock positions...2-3 inches before the "Y'" section and the WB just after the "Y", but curious to see if that's too far back.

psiconversion

iTrader: (5)

I agree with placement of the 02 sensors (non WB). You want them as close to the engine as possible as they willl provide the most accurate feedback to the PCM in that position.

Jon
PSI

oscs

iTrader: (19)

The Y pipe is probably 4ft from the motor maybe a little less/more

usdmholden

The car is turbocharged or no? I never saw turbo in your first post but it's in the replies.

Wideband O2 sensor controllers have a heater circuit built into them to keep the wideband sensor operating in it's correct temp range. You can put it anywhere in the exhaust and it will be fine. If you want to measure both engine banks with one wideband O2 then put it after the Y. If you plan to use the wideband O2 controller's narrowband output to feed into the ECM, then put the wideband close to the engine, the OEM locations will be fine, assuming your car is not turbocharged.

If it's in a turbo application, put it after the turbo, because the high pressure of the exhaust between the engine and turbine will make it read inaccurate.

oscs

iTrader: (19)

N/A application. I'm going to use both o2 sensors, one for each bank and the wideband at the Y for a "complete" reading. Not sure how the tuner is planning to use the sensors. I'm just looking for the most useable locations. Still very new to these gas engines

Sweet_SS

The is tuner going to use the O2's for controlling...a/f etc The wideband's sole purpose is for monitoring only. With using O2's, the PCM/ECU will still make changes on its own...based on how the 02's cycle. If an O2 dies then there is no feed back to the ECU/PCM and that bank will either run lean or rich. This is where the Wideband comes in. However the wideband won't be able to differentiate between both banks. There's alot more to this, but this is the general idea. As an example, my car was blowing carbon out the exhaust and was slughish under load. Busted out the laptop and logged both my O2's...bank 1 and bank 2. bank 1 O2 was cycling around 800 and bank 2 was around 200...dying and was running that side of the motor rich. My wideband did rich'n up a bit but not enough for a concern.

oscs

iTrader: (19)

Understood, thanks for the input.

Sweet_SS

Anytime.

Daz

iTrader: (18)

Did you buy this car from Datsun350Z ? If so then it use to be turboed ! I bought the hotside piping from him. Hope you got the axle thing worked out, its been a big issue with our cars on Hybridz.

oscs

iTrader: (19)

I did buy it from him. Car is back to N/A. Yeah I think I figured it out, spacers seem to have done the trick, well that and a **** ton of other little things.

Daz

iTrader: (18)

I'm trying to put a VLSD from a Na z32 in my longnose r200 and run hybrid axles. I'm thinking of trying 90-93 Pathfinder axles merged with 87-89 z31 turbo axles.

oscs

iTrader: (19)

From what I hear that is the route to go. I know a guy selling a L nose 200 and those axles for $800 if your interested. If your curious about what I've done to the rear end check out my thread in the drivetrain section on hybridz

Daz

iTrader: (18)

If he wants to part with the axles I might be game, LMK !

oscs

iTrader: (19)

Anyone have any suggestions for a good lq4 tuner?