O2 in the primary or collector - what say you?
11-19-2009, 02:38 PM
#1
O2 in the primary or collector - what say you? Can you guys give me your best argument for why you can or can't install the O2 sensors in a primary tube (one on each side) vs. the collector?????
I have always heard that putting them in the collector from the 10 - 2 o'clock postion is best....
On my application, it is difficult to get the O2 in the collector (side pipe headers) - so I'm considering mounting in a primary.
This is a 8.1 Vortec using a LS1 computer - 0411 and dbw throttle.
The primary tubes are 2 1/8" on the hooker side pipe headers.
Application on a 69 Corvette...
Thoughts?
I have always heard that putting them in the collector from the 10 - 2 o'clock postion is best....
On my application, it is difficult to get the O2 in the collector (side pipe headers) - so I'm considering mounting in a primary.
This is a 8.1 Vortec using a LS1 computer - 0411 and dbw throttle.
The primary tubes are 2 1/8" on the hooker side pipe headers.
Application on a 69 Corvette...
Thoughts?
11-19-2009, 02:47 PM
#2
Here is a picture of the type of headers I'm running - just to give you a better idea. If put in the primary, it would be in a staight section half way betweent he collector and header flange.
Last edited by 69MyWay; 11-19-2009 at 02:54 PM.
11-19-2009, 02:51 PM
#3
The "perfect" setup would be an O2 Sensor in each primary monitoring each Cylinder.
Good luck with that one..lol..it has been done though.
I would put it in the Collectors that way it can monitor all 4 of the Cylinders on that side instead of just one.
Good luck with that one..lol..it has been done though.
I would put it in the Collectors that way it can monitor all 4 of the Cylinders on that side instead of just one.
11-19-2009, 02:57 PM
#4
I appreciate the input....
here is how I did it on my last 69 Vette with an Edelbrock Pro-Flo EFI.
However, this new project has a right/left bank - so we would have to do this in both sides.
Just looking for all the + and - of doing it either way.
here is how I did it on my last 69 Vette with an Edelbrock Pro-Flo EFI.
However, this new project has a right/left bank - so we would have to do this in both sides.
Just looking for all the + and - of doing it either way.
11-19-2009, 03:25 PM
#5
The Collector or as close to the exhaust port is ideal... The PCM and software is programed to sample as a collective and not just one per cyclinder.
putting one sensor in on one primary would not be a good idea. As you would only be reading the one tube or cyclinder. You could lean out or or rich the whole bank of the engine.
I put my O2 in my bolt on Collector.. Has not given me any problems. I think the problem and solution is pertty basic. Do what you can to as close to the Design of the OEM system as possible.
As far as clocking.. I would put them either at 3 or 9 o'clock. Putting them at 6 would cause water to become a problem for the O2. Being so far from the Exhaust port, using a Heated O2 is required for better cold starts and drivablity.
putting one sensor in on one primary would not be a good idea. As you would only be reading the one tube or cyclinder. You could lean out or or rich the whole bank of the engine.
I put my O2 in my bolt on Collector.. Has not given me any problems. I think the problem and solution is pertty basic. Do what you can to as close to the Design of the OEM system as possible.
As far as clocking.. I would put them either at 3 or 9 o'clock. Putting them at 6 would cause water to become a problem for the O2. Being so far from the Exhaust port, using a Heated O2 is required for better cold starts and drivablity.
11-19-2009, 04:08 PM
#6
So...if I had it in only one - I could have a misfire or issue with one of the three remaining cylinders on a given side...and not catch it - or the one that is reading could have a problem and affect the whole side...right?
Okay...I get that.
However, assuming all things being equal (all 8 hitting hard) - what is the sciene or issue why one would be different than all four per side??? And...
If you did go in just one - would you want to stagger opposing left/right bank cylinders (based on fire order) - like running on 1 & 6 - or doing something different?
Before I mount these things back on the outside of this new project...I'd like to know that I know that I know...that putting them under the hood on a primary isn't going to work.
11-19-2009, 07:19 PM
#7
As stated above, you want to get an average of the four cylinders on each side of the engine. Hence the reason for putting it in the collector. If one were that concerned with individual cylinder control/trim, put an EGT sensor in each cylinder, run DFI and put a variable injector controller on it.
__________________
Your Source for LSX Conversion Parts!
www.psiconversion.com
Ebay Store
Facebook/psiconversion
Instagram/psiconversion
'Dont Let EFI Pass You By!'
Your Source for LSX Conversion Parts!
www.psiconversion.com
Ebay Store
Facebook/psiconversion
Instagram/psiconversion
'Dont Let EFI Pass You By!'
Trending Topics
11-19-2009, 08:19 PM
#8
Okay - fair enough. Not going to change the EFI system - that is set and running. If the single tube is a bad idea no matter what - then I will stay the course.
Just trying to get the "why" behind it - and it appears the averaging issue is what it is.
Kind of like the daughter that asked her mom why they always cut one end off the Christmas ham before putting it in the oven - the mother wasn't sure, but said her mother always did it that way. The daughter then asked the Grandmother why they cut the end off the ham. Grandma laughed and said..."because our old oven wasn't big enough to fit the whole thing so we cut if off...for the life of my I don't understand why your mother still cuts it off and she has that big ole oven to cook it in!" LOL
Just to be clear - we aren't just cutting the end off our ham...there is a reason for the location....
Just trying to get the "why" behind it - and it appears the averaging issue is what it is.
Kind of like the daughter that asked her mom why they always cut one end off the Christmas ham before putting it in the oven - the mother wasn't sure, but said her mother always did it that way. The daughter then asked the Grandmother why they cut the end off the ham. Grandma laughed and said..."because our old oven wasn't big enough to fit the whole thing so we cut if off...for the life of my I don't understand why your mother still cuts it off and she has that big ole oven to cook it in!" LOL
Just to be clear - we aren't just cutting the end off our ham...there is a reason for the location....
