sorry for the small low quality picture, I took it with my cell phone.
my question is where should the wideband be install into this downpipe?

 

i would weld a bung about 2" above the 90*

 

mine is about an inch away from the end of the pipe the only thing that sucks is trying to do idle a/f cuz if you get just a little breez of air it will jump all over the place put when you start driving it should be fine. the only reason i put mine there is cuz if you put it on the bottom of the pipe or the side it will get condensation (water,fuel) in the bottom of the 90 and will kill the sensor and being that close will kill it too. hope this help

Its now cut down too about an inch above the hood

 

^^question for both of you guys why would you run your DP up that way?

 

also should the bung be welded in straight or at a slight angle

 

the reason for mine coming out the hood is that this is a track car only and im trying to save all the weight i can.

(My wastegate dump still has to come thought the hole then im going to make a nice dress up ring)

 

thanx man

 

Genberally in a boosted application its recomended 18" from the turbine butin this case that a tough call. putting it at the end would be decent but IMO when your blowing down the track/street i somehow have a feeling closer to the turbine would be better so air doesnt give you a false reading on the wideband. though i could be completely wrong on this just seems that way to me.

I personally would contact Tony Palo T1 on this subject as i believe he was the first to do that method of DP and would know best as far as where to place the wideband for most accurate readings.

I would probably mount 4-6 inches form the turbine and do a double copper heatsink setup to aid the sensor in keeping cool

 

well when going down the track it should be putting out alot of air and the outside air i dont think it would come it when that turbo is spoolin

 

ya never know you would be surprised the amount of air force on the front of the car

 

^^^ could be wrong turbo LS but i thought the general rule of thumb was 26 inches from the turbine

 

Atleast 18" or as far away as you can on that short DP

 

i know u guys are using it on track cars, but out of curiosity is it street legal?

 

The lack of muffler and catalytic converter would mean no. On top of that it would look ridiculous on a street car.

 

having the sensor that close to the opening is going to give you extremely wrong readings at atleast idle and light throttle.

 

If I was you, I would fab up a pipe that is slightly larger than your up-pipe that has the o2 bung welded on. The total length of this piece should be a few feet so you can put the sensor 36 inches downstream from the turbine for the best results.. once it's done take off the extension piece and run straight up-pipe exhaust

edit: incase you don't know what i mean.. use a pipe about .25" or .50" larger on one side, so one side will slide over your up-pipe, that way you can just take it off when you're done.

 

agreed thats definatly going to give some seriously false readings. the sensor is pretty much out in the open and not enough collective exhaust gasses will pass around the sensor for an accurate reading. and closer to the turbine is turbulant so that wouldnt give a accurate reading either. hmm id say go with marcj's suggestion or tune it with a regular DP and then run it with that setup and see what your difference is so when your tearing down the track you know whats lean and whats rich

 

well i mean on my track car im not really going for light throttle and on a dyno with no air coming against you that would give you a good reading in boost ???? so if i do all my tuning on the dyno then i have no need to make a pipe to tune right ??? and turbols i know what u mean cuz when i go down the track vs the dyno the more air on the sensor will make it look lean

 

The problem is your sensor is right at the end of the pipe which means even on a dyno its going to be inaccurate. The reason they want a minimum of 18" from the turbine is to get an accurate reading, if its to close the exhaust gasses are very turbulant and will give false readings

 

i ended up putting the sensor in the middle of the up-pipe

 

Where I live it is they might tag you for a noise ordinance, but that's about all..

 

is that jims car?

 

i also moved mine after talking to tony

 

On that downpipe (if you can call it that) I would put it as close to the flange as you can. I don't see any downside to it and Turbo-LS is right about problems with it being too far out.

 

sorry boosted but that is hideous