brando1985

Hello,

I have an LS1 with a PT67 sitting up front. I'm finishing up the build, but have a pretty novice question that needs answered.

I'm planning on running HP Tuners, and I already have a wideband. Since I'm going to be tuning off wideband readings, are stock o2 sensors even necessary, and if so, where should I mount them?

Thanks!

Brando

John_D.

iTrader: (2)

If you're going to be running in Closed Loop, then you'll need sensors, or have the wideband emulate them.

If you're always going to be running in Open Loop, then you don't need the stock sensors.

To get an accurate reading when in boost, a sensor should be after the turbo. But for stock sensors reporting at idle and part-throttle, you can run them before or after the turbo.

brando1985

Thanks John. Since I want closed when cruising, I need to put both of my stock sensors in the downpipe. Should I stagger them and put one further down than the other, or have them side by side?

Thanks again,

Brandon

John_D.

iTrader: (2)

I don't think the relative placement will make a difference. I remember reading a magazine article online a couple of weeks ago, I think it was linked from the Innovate site, about a WB shootout. The magazine doing the shootout had several WB's in a ring and a couple just a little downstream from the main ring (since they ran out of room).

Sideways240sx

iTrader: (22)

Everything i have read said for stock sensors.. our front 02's, put them as close to the manifolds as possible(before the turbo), and then the wideband in the downpipe.

That is also how most kits are i believe.

Chris

Old Geezer

iTrader: (3)

High egt and system backpressure that the sensors will see, if installed B4 the turbo, will cause them to read differently, and have a shortened life.
The WB should be installed in the downpipe, at an angle higher than horizontal.[Prevents accumulation of moisture]. Exposing the WB to egts in the 1600* range will toast it..
We always install at least 16" from the turbo.. Even more, if access is available.

unclebens

iTrader: (2)

brando, how do you like that pt67, smaller than most ls1 guys run. How quick does that spool?

Johnv

If you put the factory o2s after the turbo (single turbo) , they will not work as they would in a factory setup and trim the fueling from each bank individually! to work properly in closed loop they will need to be pre turbo and placed so they only sample gasses from each indvidual bank before the manifold merges.

wide band needs to be after the turbo in the downpipe.

dudeman

iTrader: (43)

why do you need stock 02's anyway? what is the difference between open loop and closed loop? is there any reason to keep them?

tomz28

iTrader: (20)

pm the guy

urwifesman

Hey gang, new and looking for help also on this .... I personally was going to measure from the rear cylinder using factory measure measurements to the O2 then do the same for my single turbo setup I'm doing on my avalanche. But I am curious on the length of where to install them along with where to install my third. Any other hp tuner guys out there with any help??

01ssreda4

iTrader: (96)

Good post, my stockers are in my downpipe before the turbo, and my wideband is about 18 inches after the turbo. Seems to be reading fine so far.

truckdoug

iTrader: (25)

i'm pretty sure you can run them before or after the turbo with little difference.

they dont have a pump cell like a WB does (to be affected by drive pressure)

and in a single turbo set up, how isolated could the one bank's sensor be in the presence of drive pressure?

pantera_efi

iTrader: (1)

Hi Ur, I invented the Four Wire EGO for NTK. (1989)

The experience learned by doing so taught me much about O2 sensors.

First, the normal operational max temp range is 1650F with a lean read when the gas temperature is greater.
Second, Gas Pressure effects the sensor calibration, the read.
The change in report is not great though MY ECU does have an object setting for "before" turbo EGO placement AND EMAP.

This FINE TECH was stated ABOVE by Geezer TEN years ago.

My guess is that you do not believe him ?

Lance