Hi guys,
Wondering where the best placement for an 02 sensor would be?
SBC on Nitrous for Drag Racing. Headers are with Merge Slip-On collectors.
Should I put it in the collector even though it is slip-on? Where in the collector? Or would it better to have it in the primary tube? Where in the primary tube?
O2 sensor placement
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Belgian1979
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Re: O2 sensor placement
If just one sensor, you're limited as the sensor would have to sense as much cylinders as possible. Since you work with a slip on collector which will introduce free oxygen, this will not give good results.
If you have 8 sensors (on per cyl) you have to put them in the primaries, but then you need to have an ecu or other device give you a meaningful output which is the average of all AFR values.
In any case, with nitrous, I would place them as far from the head as much as practically possible while at the same time trying to get them in as much of an upright (up to 10° inclination) as possible.
If you have 8 sensors (on per cyl) you have to put them in the primaries, but then you need to have an ecu or other device give you a meaningful output which is the average of all AFR values.
In any case, with nitrous, I would place them as far from the head as much as practically possible while at the same time trying to get them in as much of an upright (up to 10° inclination) as possible.
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Walter R. Malik
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Re: O2 sensor placement
At least 12 inches from any air source which is not exhaust gas and certainly not after any potential exhaust air leak.lekid wrote: ↑Wed Apr 04, 2018 9:04 am Hi guys,
Wondering where the best placement for an 02 sensor would be?
SBC on Nitrous for Drag Racing. Headers are with Merge Slip-On collectors.
Should I put it in the collector even though it is slip-on? Where in the collector? Or would it better to have it in the primary tube? Where in the primary tube?
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Re: O2 sensor placement
I've installed one in the exhaust heat crossover in the intake manifold. This close to the cylinders it is interesting how much easier you can see the fuel puddle overrun on coasting and lag on acceleration as the mass of liquid fuel moves through the intake when you change throttle position.
When there has been a moderate 75 ~ 100 HP load for several seconds and the throttle is suddenly closed, the air is cut off with the manifold runners containing the 100 HP fuel mass, probably 1/2 of which is in liquid film on the floor and walls, the A/F drops from the 16.5~17/1 in the mid-load to as low as 10/1 for a moment, and then over a period of about 3 or 4 seconds coasting with 22" to 24" Hg progresses up to about 13~14/1 where it usually is coasting above idle RPM. Coming to a full stop at idle speed 500 RPM 17"~18" Hg the A/f is 12.5/1 or so, it varies some with engine temperature, leaner cold = less vaporization and richer hot = more vaporization.
When there has been a moderate 75 ~ 100 HP load for several seconds and the throttle is suddenly closed, the air is cut off with the manifold runners containing the 100 HP fuel mass, probably 1/2 of which is in liquid film on the floor and walls, the A/F drops from the 16.5~17/1 in the mid-load to as low as 10/1 for a moment, and then over a period of about 3 or 4 seconds coasting with 22" to 24" Hg progresses up to about 13~14/1 where it usually is coasting above idle RPM. Coming to a full stop at idle speed 500 RPM 17"~18" Hg the A/f is 12.5/1 or so, it varies some with engine temperature, leaner cold = less vaporization and richer hot = more vaporization.