13brv3

Greetings,

I'm going to order a DP soon, and I want to have a 2nd O2 bung welded on for a wideband sensor. Does it matter where I place the bung on the DP? I read a few posts that questioned the life of the wideband sensor when placed too close to the turbo, so I would be inclined to put it further downstream. This might keep it alive longer, and would also make it easier to put in, and take out if I choose not to leave it in full time. Since most dyno shops probably use the "up the wazoo" method, I can't see that it matters how far away it's located.

Any comments or suggestions appreciated as always.

Thanks,

P'cola FD

I really don't know where the best place to put it would be. All I know is that if you do get a wideband, I am sooooo gonna bug you to let me use it.

13brv3

I can be bought. Beer usually does the trick

I don't really want to spend the time or money to do any of this now, but my car is still not behaving, and I have some high RPM hesitation going on. The DP is one of the things that might help, and a wideband would give me a better idea of what's going on now, and for future tuning. I'm a little worried that I may have an injector acting up, and I want to make sure that I'm not leaning out and tempting fate with an apex seal. A wideband may be cheap insurance, and I can also use it to tune the airplane ECU.

BTW- what color is your car? I saw a red FD heading West on I-10 toward the bay bridge around 2:00 pm today. Was that you? I was in the company van, not the FD. Mine's black, and the tag is "13B RV3" so I shouldn't be hard to spot

Cheers,

reza

I would put it near the end of the DP. make sure there is enough space to put the O2.
I made a mistake once, soon I will have 3 Oxygen Bung on my Downpipe...

reza

skunks

I agree, I think I read some where that your not suppose to put it too close to the engine because it gets too hot and gives unaccurate readings. I'm not 100% sure about this though.

P'cola FD

Mine is red, but you didn't see me on I-10 today. Beer is a very acceptable loss for the use of a wideband. My car is also pretty noticeable. It is the VR fd with hood leprosy.

reza

If its too close to the turbo, it will be too hot, and shortened the life of the super expensive oxygen sensor.
but for sure, you have to put it before the cat.
I welded mine on the wrong angle, now gotta make the third bung.

Reza

13brv3

Great, so we've established that it should go toward the aft end of the DP. Now the big question is where exactly. Unfortunately, I don't have the sensor, or the DP, so it's going to be hard for me to determine a spot that works. Is the sensor the same length as the stock sensor?

Reza, you seem to be our resident expert on placement. Where will you put your 3rd bung? Do you have a picture? I assume that pointing it straight down at the rear of the pipe would make the end of the sensor the low point of the car, and tend to whack it off if you ran over anything. My goal is to specify the location of the bung, so it can be welded on before I get the pipe.

Thanks for all the info.

rxrotary2_7

twords the end of the DP.
why not spend the money on fixing/finding out what your prob is?
what mods do you currently have that a WB is going to be benificial? looks like you have none. you can not make an adjustments via a haltech or PFC... this money could be well spen on other things before the need for a WB. the WB is not going to pinpoint your problem. oh, and btw, you dont want to keep it in full time. that is my $.02

13brv3

Thanks for the comments.

I would be happy to spend the money to fix/find the actual problem, but don't have a clear direction to go. I've searched for high rpm hesitation issues, and there's no clear "fix". I've only had the car a couple months, and have stated that I wanted to get it working correctly "stock", so I'd have a baseline for future mods. So the answer is- I'd love to spend the time and money on fixing the current problem- any suggestions?

As for why the WB now- I plan to modify the car extensively, since it's just a weekend toy. At some point I will need the WB, so why not get it up front, and collect some data along the way. Also, I don't agree that it won't help find the current problem. If I'm having a lean or rich misfire, won't it point that out?

Cheers,

rxrotary2_7

how about we start here....describe your problem. does it feel like a fuel or ignition problem? at what points does it occur? when? all the time? when the car is cold?
give us some explination of your problem. i am more than willing to help.

13brv3

Thanks for the offer. I just posted a new thread with all the details. I forgot to answer your specific questions though. It does happen all the time.

https://www.rx7club.com/forum/showth...hreadid=128092

Thanks,

reza

Well. put it where you like it near the end of DP.
Just so you make the right decision.
The length of NTK sensor is about 2.5 inch or 5cm.
Add to the length the thickness of the bung. so about 2.75 inch clearance.
Now you need to know that the DP will move along with the engine as it goes under load. So make sure you leave enough room for the O2 sensor.

For me, I tried to have the bung to towards the passenger side of the car, thus I can take it out when I don't need it anymore, by just jacking the car a little bit, and reach in. That is my thinking now.

Reza

13brv3

Great info Reza. Thanks!

rxrotary2_7

i think corkey bell put it best in his book. "a WB O2 is like knowing the balance of your checking account. it will tell you the balance, but NOT what you can do about it." or somthing to that effect. i think i got the quote right, but i could be off a little.