Hey… Just got my pre-built 1.5 and have some questions.. I have a 93 RX-7 and I would like to get an idea on how far from the turbos I should have the sensor. I have two on my down pipe but they may be too close to the turbos. The next question is which one I should get… NTK, Echlin, Bosch ect…

 

Place the sensor bung as far down the downpipe as you can.

 

NTK, Echlin, Bosch are all the NTK sensor in different boxes. Get whichever one you can find, as they are hard to locate these days. I think there has been a greater demand for the sensors than the manufacturer anticipated since lots of people have been buying WBO2s lately.

-Max

 

I placed my sensor about 3" from the bottom of the dp and when comparing it to the dyno wb that cost thousands its always within .1

STEPHEN

 

Thanks guys.. I wanted to get a new DP anyway.... I want to get it jet hotted first... So adding the bung about 3-4 " for the botton will have to be done first...

next question.. what DP to get.. need to do a search

 

Why would you place the sensor as far down the DP as possible? Mine is mounted about 4-5 inches after the V-band... which is pretty damn close to the TOP of the DP.

My logic is that mounting it higher will provide faster results. In fact... a test was done on the dyno with a FJO mounted close to the turbo... and compared it to the sensor in the tail pipe. There was a 200 RPM difference in A/F curves. The curves were the same... simply shifted in time.

I would like to know as quickly as possible when my A/Fs change...

I'm not flaming anyone... I'd just like to hear the logic behind it.

 

I wasn't speaking from personal experience but my research into it and the comments of others who own the FJO.

Apparently, you will get more stable results further away from the turbos and more life out of the sensor (if you care). When you talk about your sensor location, are you talking about an FD or your Supra? Either way, if you are getting accurate results and the sensor isn't dying too early, sounds like your placement works. Always good to hear more view points, especially regarding the time lag -- didn't think about that one.

 

This is on the Supra.

BTW... I know lots of guys who run nothing but leaded 110+ octane fuel and have had their FJOs for over a year and still going strong.

I've got a spare sensor in the garage though just in case.

I didn't believe that there would be a 200 RPM lag either until I saw it with my own eyes.

 

Thanks for the info Jim, I'll store that in my data banks for when I go forward with the wideband.

 

I'm going to place the bung as far down the downpipe as possible. Longevity is key for me...I can deal with shifting 200 rpms

 

The closer to the heat source that faster the sensor is going to fail. There really isnt much difference in reading if its placed in the middle or at the top.

 

I guess that's more of a concern with you rotary guys than with us piston guys as my EGTs aren't nearly as hot as yours are.

As far as the leaded fuel concern... like I said as far as us Supra guys are concerned it hasn't been nearly the problem that we thought it was going to be.

I'll let you know if I kill my sensor anytime soon from the heat.

 

My little blurb.
http://www.negative-camber.org/crispyrx7/wideband.htm

Technical inaccuracies please let me know
HTH.
Regards,
Crispy

 

Actually the reason I placed mine in the bottom of the down pipe was because of heat...HOWEVER not because of sensor life but rather accuracy.

The sensor is heated so that it stays in a certain range of heat, if it gets away from that range then its readings are going to be off. My understanding is that the closer you are to the engine the greater the chance that your exh temps (especially on a rotary) are going to exceed the heating element causing the wide bands calculations to be off

STEPHEN

 

Hmm post didnt work.. anyway

Crispy nice write-up..... now DP question.. MY dp can with the car.. dont have an idea who made it but it has 3 bungs on it... one thats near the 12 O'clock position is about a foot from the turbo's... the one thats about 20 inches is about the 3 O'clock area... any pointers? or should I just get a new DP and have one welded ( I would like to jet-hot it if I do)

Tekno

 

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