Just as the title says... Where would the best place to mount the Oxygen sensors on my DIY setup?

First thought was just after each header collector, but on the turbo header theres not enough room after the collector.

Another idea was to run one on the cross over and one on the downpipe..

Next idea was to run both on the downpipe.. One about 12" after the oulet, and another just downstream about 12"...

Or just not run O2's at all, and try to tune them out, if possible? I do have a Tweecer, if anyone has any knowledge with tweecer tuning..

 

I would place one 6-8" after the turbine in the downpipe, and the other one i would run right by the bellhousing of the transmission.

 

I tweeked out the 02s for several months because I was too cheap to buy new 02s. If you have larger injectors it is very difficult to get the AF dialed in this way. Tuning the MAF curve won't do it, you have to tune injector breakpoints, injector offsets, etc, and its difficult. I wouldn't really recommend it, 02s compensate for alot of tuning errors.

I would actually recomend running both in the crossover, even though they will only read 1 bank it should work fine.

 

well what would be the diference in placing them both on the downpipe, vs the cross over, other then one is reading post turbo, and one pre turbo..

 

Post is more important

 

i have not measured any significant AF difference between pre and post.

really, you should be able to use any combination. they heat up better preturbo, thats why i would put them both in the crossover. try to keep them in an easy to remove location incase you ever want to run straight race fuel.

 

You can have overheating problems with o2s before or even close after the turbo. A friend told me about how his wideband o2 ceramic broke off in the header on his turbo MR2 that traps 123mph.

 

il be running 100 octane for the street.. which is unleaded im sure. and ocasionally run race fuel at the track (114-116 octane)
O2's and leaded fuel dont mix, from what i understand?


Il need to play with the spark tables, and probably force open loop on idle, since my Ecam doesnt like to idle smoothly, adjust the basics like injector slopes, offsets, ect...

Anyone on here have a good Tweecer bin file i could start off with? I have the ZAO calibration ( 94-95)

 

Everyone I've spoken to says leaded race fuel will not hurt O2 sensors, only cats. I plan on running C16 when I crank up the boost and doubt my car would run if I removed the sensors.

Briane

 

I'd install them pre turbo, although there is room for debate, cartech kits i have seen have them pre turbo yet the TTI kit have 1 in the crossover and 1 in the DP

 

Both of mine are right next to each other in the downpipe by the bellhousing.

 

How about this. Would you rather have the chance that the tip of the sensor could break off and go into the blades of the turbo or after. Second, running pure race gas will likely prematurely kill cats and O2 sensors, but how often do you run PURE racegas. Run a 50/50 mix and you should have no worries
issuez

 

so im taking it that placing them on the downpipe ( both O2's) would be my best bet... Wont be running cats, or any emissions equipment, so i think i might be good to go.
Going to run 100 octane for the street, and 116 for the track ocasionaly.