Single turbo front crossover pipe for AC
Thread Starter
Teching In
Joined: Feb 2021
Posts: 4
Likes: 0
From: Las Vegas, NV
Single turbo front crossover pipe for AC I have a 3rd gen 5.3 that I'm doing a single turbo build on. Plan is to use my flipped truck manifolds and run a hotside crossover pipe in front of the motor to a y-pipe/T4 flange so that the turbo is sitting on the passenger side. I need the crossover pipe to clear the AC compressor (I live in Las Vegas so AC is a must) and I need a spot for pre-turbo bank 1/2 narrowband sensors as I want to run closed loop.
My original plan was to run a log style manifold with crossover in the rear, but as far as I can tell, theres really no good spot for a bank 2 sensor to run closed loop... please correct me if I'm wrong as I'd prefer to run this setup instead.
So does anyone have any pictures or suggestions of a front crossover setup? Or any suggestions to running closed loop with a log manifold set up?
Thanks.
My original plan was to run a log style manifold with crossover in the rear, but as far as I can tell, theres really no good spot for a bank 2 sensor to run closed loop... please correct me if I'm wrong as I'd prefer to run this setup instead.
So does anyone have any pictures or suggestions of a front crossover setup? Or any suggestions to running closed loop with a log manifold set up?
Thanks.
Last edited by catch_kc; Mar 8, 2021 at 09:50 AM.
On The Tree
Joined: Feb 2011
Posts: 120
Likes: 20
From: Tucson, AZ
Everywhere I have read say to stick the O2 sensors in the downpipe. There are a couple threads here saying the max temp rating of the O2 sensors are around 600°f, and a turbo car is goin got get hotter than that. The other thing I have read is they have accuracy issues because of the the pressure pre-turbo.
I have both O2 sensors in my down pipe along with a wideband.
I have both O2 sensors in my down pipe along with a wideband.
TECH Regular
Joined: Nov 2018
Posts: 467
Likes: 116
It's not just the added heat the messes with the sensors. Pre-turbo is under pressure and being under pressure throws the sensors accuracy off, they can't read the correct O2 levels.
Wire both narrow band O2 plugs from the harness into a single plug so one narrow band is feeding signal to both circuits in the ECM, then just run a single narrowband in the downpipe and let both cylinder banks get the same fueling. That's what I did, but I'm also running speed density OS.
Wire both narrow band O2 plugs from the harness into a single plug so one narrow band is feeding signal to both circuits in the ECM, then just run a single narrowband in the downpipe and let both cylinder banks get the same fueling. That's what I did, but I'm also running speed density OS.
Thread Starter
Teching In
Joined: Feb 2021
Posts: 4
Likes: 0
From: Las Vegas, NV
Thanks for the input. This will be my first turbo build so I'm trying to learn as much as possible while planning the build out. Want to buy/build right the first time so that I'm not reinventing the wheel later on.
So another beginner question here, but is it less important to monitor o2 on each bank separately in turbo applications like it is in NA applications? Also, I'm tracking how NB sensors reading inaccurately pre-turbo due to higher pressures and such, but are there not NB sensors specifically designed for turbo applications?
Thanks again.
So another beginner question here, but is it less important to monitor o2 on each bank separately in turbo applications like it is in NA applications? Also, I'm tracking how NB sensors reading inaccurately pre-turbo due to higher pressures and such, but are there not NB sensors specifically designed for turbo applications?
Thanks again.
On The Tree
Joined: Feb 2011
Posts: 120
Likes: 20
From: Tucson, AZ
Its important when dealing with your average every day user who wont really be mindful of their car. I know I'm more mindful of the health of the engine because I don't have the ability to monitor much of anything because of how its setup. Also I don't it will throw a CEL or anything, so unless you are monitoring it you wont know if something is happening.
Having the o2 sensors adjust the banks wont necessarily save an engine either. There are a few instances of an injector getting plugged so the computer adjusted everything and it still "looked" good because the other cylinders were running rich to compensate, yet the pugged cylinder popped due to a lean condition. Reading your plugs is going to be the best indicator of how your engine is running.
The one factory turbo car I owned has the O2 sensors after the turbo, but its got twins on a v6 (92 Stealth TT). The newer cars I'm looking at also all have the O2 sensors after the turbos (Taurus SHO)
As for the NB specifically designed for the pressure side pre turbo, no idea.
Having the o2 sensors adjust the banks wont necessarily save an engine either. There are a few instances of an injector getting plugged so the computer adjusted everything and it still "looked" good because the other cylinders were running rich to compensate, yet the pugged cylinder popped due to a lean condition. Reading your plugs is going to be the best indicator of how your engine is running.
The one factory turbo car I owned has the O2 sensors after the turbo, but its got twins on a v6 (92 Stealth TT). The newer cars I'm looking at also all have the O2 sensors after the turbos (Taurus SHO)
As for the NB specifically designed for the pressure side pre turbo, no idea.
