Headers and O2 sensor

[1987R30]

I am considering putting headers on my 87 R30. Im looking for some experience with headers and the proper way to use an O2 sensor (what sensor, where to locate the sensor, and does it work well). Ive seen so many old trucks that run terrible. Mine runs perfectly and I dont want to mess it up. I still have a 3” factory Y pipe (single exhaust) that i want to convert to duals. So, who’s done it successfully?

 

[PrairieDrifter]

My autometer kit has a Bosch sensor and says they want it right after the manifold collector in the pipe. Or for headers, on the collector where all the pipes meet at the flange.

Have to mount them near vertical and as close to the manifold as possible, to keep condensation from building up and to heat the sensor up as fast as possible.

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[75gmck25]

If you have a heated sensor it can be farther down the pipe, away from the exhaust manifold, since it does not rely on engine heat to come to operating temperature. Simple two wire sensor needs to be as close as possible to the collector so it heats up quickly. All should be no more than about 30 degrees off vertical, to keep condensing moisture off the sensor.

 

[Edelbrock]

I am considering putting headers on my 87 R30. Im looking for some experience with headers and the proper way to use an O2 sensor (what sensor, where to locate the sensor, and does it work well). Ive seen so many old trucks that run terrible. Mine runs perfectly and I dont want to mess it up. I still have a 3” factory Y pipe (single exhaust) that i want to convert to duals. So, who’s done it successfully?

Another resource might be to call custom exhaust shops. I'm sure they do that kind of work all the time, and would have some experience with what works best.

 

[CountKrunk]

I assume you have a TBI unit? I think 87 is when they started rolling out, but not on everything.

 

[gmbellew]

If you're running good as is, and with the limitations of TBI, I'd just leave the exhaust manifolds on there. Headers wont add much from what I've read. Look at a new exhaust coming off the manifolds if you need a new exhaust system.

 

[Ricko1966]

It should be a TBI 305,and a single wire O2 sensor,so it's going to have to stay fairly stock to run the TBI. That means no big cam,if you want to run headers the O2 sensor has to stay as close to the exhaust ports as you can keep it,and be in the collector. I'd convert to a 3 wire O2 sensor.

 

[1987R30]

I assume you have a TBI unit? I think 87 is when they started rolling out, but not on everything.

Yes TBI. 454/TH400. Stock manifolds

 

[1987R30]

If you're running good as is, and with the limitations of TBI, I'd just leave the exhaust manifolds on there. Headers wont add much from what I've read. Look at a new exhaust coming off the manifolds if you need a new exhaust system.

Leaning this way. I like the headers since i could do my own dual exhaust. But thinking i will just pay for 3” stainless duals from the manifolds back. Thanks

 

[Ricko1966]

Leaning this way. I like the headers since i could do my own dual exhaust. But thinking i will just pay for 3” stainless duals from the manifolds back. Thanks

On a 454 I'd want headers. I was thinking you were 305.

 

[Edelbrock]

I am considering putting headers on my 87 R30. Im looking for some experience with headers and the proper way to use an O2 sensor (what sensor, where to locate the sensor, and does it work well). Ive seen so many old trucks that run terrible. Mine runs perfectly and I dont want to mess it up. I still have a 3” factory Y pipe (single exhaust) that i want to convert to duals. So, who’s done it successfully?

From my understanding, headers will not improve the performance of the engine on their own. Headers only allow the potential for other performance upgrades to be utilized in the most effective way. For example:

(These numbers are not precise, they are just to illustrate a concept)

Stock engine with OEM manifolds - performance: 10.00 baseline
Stock engine with headers - performance: 10.05 No appreciable difference
Modified engine with OEM manifolds - performance: 13.20 very nice
Modified engine with headers - performance: 13.80 Ideal

The stock manifolds allow enough free flow of the exhaust to be sufficient for s stock engine, so increasing the flow wont help unless you increase the amount of engine performance to utilize that extra flow. For example, if you bored it way out or made it a stroker, modified for very high RPM, installed forced induction etc.

Its kinda like installing a speedometer that goes up to 500 MPH. If there are no other mods made to a car, then the upgraded speedometer is nice and fancy, but is not actually of any use.

I could be wrong, but that's my understanding of it.

Most manufacturers spend millions to get the more power and efficiency, so if its something really simple and easy to do - they would have already done it. The Mythbusters TV show did a lot of experiments on this kinda thing.

Obviously companies that manufacture headers will disagree and say that all engines will perform WAY better with their specific design of headers, and maybe they are correct. Or maybe they just want to sell headers.

 

[1987R30]

From my understanding, headers will not improve the performance of the engine on their own. Headers only allow the potential for other performance upgrades to be utilized in the most effective way. For example:

(These numbers are not precise, they are just to illustrate a concept)

Stock engine with OEM manifolds - performance: 10.00 baseline
Stock engine with headers - performance: 10.05 No appreciable difference
Modified engine with OEM manifolds - performance: 13.20 very nice
Modified engine with headers - performance: 13.80 Ideal

The stock manifolds allow enough free flow of the exhaust to be sufficient for s stock engine, so increasing the flow wont help unless you increase the amount of engine performance to utilize that extra flow. For example, if you bored it way out or made it a stroker, modified for very high RPM, installed forced induction etc.

Its kinda like installing a speedometer that goes up to 500 MPH. If there are no other mods made to a car, then the upgraded speedometer is nice and fancy, but is not actually of any use.

I could be wrong, but that's my understanding of it.

Most manufacturers spend millions to get the more power and efficiency, so if its something really simple and easy to do - they would have already done it. The Mythbusters TV show did a lot of experiments on this kinda thing.

Obviously companies that manufacture headers will disagree and say that all engines will perform WAY better with their specific design of headers, and maybe they are correct. Or maybe they just want to sell headers.

Nice write up. Thank you. It all registers with me as truth

From my understanding, headers will not improve the performance of the engine on their own. Headers only allow the potential for other performance upgrades to be utilized in the most effective way. For example:

(These numbers are not precise, they are just to illustrate a concept)

Stock engine with OEM manifolds - performance: 10.00 baseline
Stock engine with headers - performance: 10.05 No appreciable difference
Modified engine with OEM manifolds - performance: 13.20 very nice
Modified engine with headers - performance: 13.80 Ideal

The stock manifolds allow enough free flow of the exhaust to be sufficient for s stock engine, so increasing the flow wont help unless you increase the amount of engine performance to utilize that extra flow. For example, if you bored it way out or made it a stroker, modified for very high RPM, installed forced induction etc.

Its kinda like installing a speedometer that goes up to 500 MPH. If there are no other mods made to a car, then the upgraded speedometer is nice and fancy, but is not actually of any use.

I could be wrong, but that's my understanding of it.

Most manufacturers spend millions to get the more power and efficiency, so if its something really simple and easy to do - they would have already done it. The Mythbusters TV show did a lot of experiments on this kinda thing.

Obviously companies that manufacture headers will disagree and say that all engines will perform WAY better with their specific design of headers, and maybe they are correct. Or maybe they just want to sell headers.

nice writup. Thank you. I’m gonna stick with my stock manifolds. They’re in great shape.

Now do I do 2.5” or 3”? Brian Harris at tbichips.com says 2.5” duals. AI says 2.5” for low end torque. The exhaust ports of the stock manifolds are 3”. What do ya’ll say?

 

[bucket]

Decades of independent testing has shown that long tube headers often produce gains in power, even on bone-stock engines and often in the low to mid range of the power band as well. It's a common misconception that long tube headers only produce gains at high rpm and on modified engines.

The amount of power gain is dependent on each engine and exhaust setup. There's way too many variables to just blanket statement anything. Is it a difference that can be felt? Sometimes no, not really. But often times it is a significant difference and it can be felt in daily use.

In the case of a 454, even a stock one, yes a set of long tubes with proper sized exhaust tubing and unrestrictive mufflers will produce decent gains. It's not just advertising hoopla.

 

[bucket]

Oh yeah and one other thing... that Mythbusters TV show was a crock of sh!t. So much of that "testing" they did was an absolute joke and did not account for real life variables and conditions.

 

[Bloodhound1981]

If you haven't already, you MUST watch Engine Masters. So much of this type of stuff was tested on the show.