3.2 with bursch headers, no o2 bung?

[nb6179505]

As the description says I have a 3.2 us spec Carrera, I currently have a cat bypass and single in single out muffler by bursch, which to me sounds a little too much like a muscle car.

Now I've seen cars with straight headers and 2 in 2 out mufflers, this set-up is in my garage and I hope to install.

One, is the install difficult? Do I run the risk of breaking head studs when removing the factory heat exchangers?

Two, the bursch headers don't have an o2 sensor bung, do I leave it off or have someone weld in a bung? What are the consequences of each?

-And if I weld in a bung, where should it be done, where the three cylinders collect to one before they go to the exhaust?
-if no sensor, what do I do, just cut it off or is there some kind of wiring technique to loop it into itself?

Thanks guys.

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[yelcab1]

Anytime you mess with an old air cooled Porsche exhaust, you plan for the worst. Some drilling required.

Weld in an O2 sensor bung at any exhaust shop. $20 is what it takes. Have it done at the point after the exhaust pipes all collect together.

[Bob Kontak]

Originally Posted by nb6179505

Do I run the risk of breaking head studs when removing the factory heat exchangers?

You run the risk of breaking the exhaust studs in the heads.

Bruce Anderson (RIP) said in one of his 911 handbooks to heat the nuts to cherry red before removing them. You can do this with MAAP gas if you have a little time. If you have more time than that you can do it with propane. Ultimate is oxy/acet but not everybody has those.

If you do this your risk is greatly reduced. I see twisting off a stud or two as the biggest speed bump you could encounter. Take extra steps to avoid this.

You may need some special wrenches but I am not sure. I believe you do on older 911's. Get that lined out before you start.

Also, use six point wrenches/sockets rather than 12 point.

Can you post a pic of one of the headers. My be helpful to identify a suggested location for the bung.

[Trakrat]

Originally Posted by nb6179505

One, is the install difficult? Do I run the risk of breaking head studs when removing the factory heat exchangers?


-if no sensor, what do I do, just cut it off or is there some kind of wiring technique to loop it into itself?

Make sure to remove the heat exchangers when your car is cold... spray PB Blaster liberally around all the nuts.
The most important thing to do is make sure you are squared up when your socket is on the nut to remove it.
Unless you headers are rusted and filthy, about the worst you may end up doing is taking the entire stud out with the nut still stuck on.
Just take your time... and don't be in a hurry.

As for the O2 sensor... I've heard that you could simply unhook the sensor and not even use it. Heck... I've known some people who have been running dead 02 sensors in their car for years without even knowing it.

[larrym]

i run similar setup in my 914-6 with an '89 3.2 - with a 911-sport muffler
(yes noisy & drones at times)

- i welded in bungs long ago (so i could run a dual sensor AFM meter for tuning the carbs on my old 2.8)

Steve Wong says we should always run 02 sensors with DME - he says sensing only one side is "good enuf" - i run his cat-bypass/headers spec chip

so, i now run the stock 02 sensor on one side & an AEM AFM on the other side

i can report that running a sensor improved my fuel economy & that the car now cruises mostly in the 14.8-15.2 range

interesting report on Bursch noise - i have a new Bursch on shelf & was thinking of trying it vs the sport-911 to get rid of the oft-reported "drone"

p.s. - you can run only the AEM sensor & use it to also feed the DME - there is a good thread here about that

[larrym]

yes - you will probably break some studs

- it happened on my 3.2 engine that had about 70,000 miles on it; (and on half-dozen other Porsche engines i've had)

there are lots of threads on this subject - just google it

fwiw - lots of snake oil in the threads - some get lucky - most don't

i simply bought the Stomsky kit - expensive - it works!
(i may never use it again, but it was worth every penny)

Originally Posted by nb6179505

Do I run the risk of breaking head studs when removing the factory heat exchangers?
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[nb6179505]

Originally Posted by larrym

yes - you will probably break some studs

- it happened on my 3.2 engine that had about 70,000 miles on it; (and on half-dozen other Porsche engines i've had)

there are lots of threads on this subject - just google it

fwiw - lots of snake oil in the threads - some get lucky - most don't

i simply bought the Stomsky kit - expensive - it works!
(i may never use it again, but it was worth every penny)

What's the stomsky kit for? I have a stomsky psj but what do they have for exhaust?

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[nb6179505]

So it sounds like the consensus is to have a shop swap it and weld in a bung? Is that fair to say, because if they break a stud they can deal with it...

If I break a stud it's a whole new can or works having to replace them?

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[Bob Kontak]

Originally Posted by nb6179505

If I break a stud it's a whole new can or works having to replace them?

I am going to tell you once again. Heat those m*other f*ckers cherry red and you will be fine.

You will not break studs.

You need to get past this first check point. Just do, don't try, as Yoda says.

Stromsky kit is for failure.

[nb6179505]

Originally Posted by Bob Kontak

I am going to tell you once again. Heat those m*other f*ckers cherry red and you will be fine.

You will not break studs.

You need to get past this first check point. Just do, don't try, as Yoda says.

Stromsky kit is for failure.

So red hot then remove while hot? Sorry if I sounds stupid for asking!

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[Reiver]

Or just do this....drill a hole, bolt this on.....I did this for my AFR sensor on my SSI's...no reason to remove them..

https://www.summitracing.com/parts/sum-690125/overview/

[nb6179505]

Originally Posted by Reiver

Or just do this....drill a hole, bolt this on.....I did this for my AFR sensor on my SSI's...no reason to remove them..

https://www.summitracing.com/parts/sum-690125/overview/

Good idea! And it works just fine, no leaking from exhaust flow?

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[Reiver]

Originally Posted by nb6179505

Good idea! And it works just fine, no leaking from exhaust flow?

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None at all....very simple fix and very common

on my SSI's now for 3 years

[nb6179505]

Originally Posted by Reiver

None at all....very simple fix and very common

on my SSI's now for 3 years

Thanks for the picture, may be off topic but does the exhaust drone? This is my daily, but we do also have a panamera turbo for long drives...

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[O=O]

I'm doing this right now on my 87 3.2. My car has ~140,000 and the nuts came right off however its been a California car all of its life. I won't be welding on an o2 sensor. I heard it'll run a little richer which is fine by me.

[Jesse16]

As O=O's experience, I removed my exhaust many years ago at 160k miles without any issues but plenty of worry. My car also has spent its life in GA and FL and was, is not rusty. After plenty of PB Blaster, I used the technique of giving each nut a little tweak "righty for tighty" and usually would hear a little creak. Then go lefty and each one came right off. Read that one on this forum.
I have no torch capable of red-hot heat, only propane.

[Bob Kontak]

Originally Posted by nb6179505

So red hot then remove while hot? Sorry if I sounds stupid for asking!

Definitely. Not a crime to cycle a few times with penetrating fluid. PB Blaster or the like. Hit it with the penetrant after it cools down a minute but use the wrench when very hot.

By the way, I have broken one off when I did did not heat them up when I thought the nuts would be "fresh" enough from the last exhaust pull a few years prior. I lucked out and did not need a special tool but it sure burned a lot of time.

[Bob Kontak]

Originally Posted by Jesse16

I have no torch capable of red-hot heat, only propane.

The heat is plus or minus 3,600 F.

Keep the blue tip where you want the heat for a good minute.

Try it by putting a 10mm bolt in a vice and put the blue tip to the end of the threads while the tank sits on the bench.

They don't get bright cherry red and glow unless you are feeding the torch oxygen. It will get red hot but when the torch is pulled off the red will go away. Still plenty of heat to get to the nut loose.

[Bob Kontak]

Open question. Is there any value in welding a bung on each header collector on a 3.2 and plug one but have an access port for an analyzer or to swap sides with the O2 sensor (assuming the wire would reach)?

[Reiver]

Originally Posted by Bob Kontak

Open question. Is there any value in welding a bung on each header collector on a 3.2 and plug one but have an access port for an analyzer or to swap sides with the O2 sensor (assuming the wire would reach)?

Yes...that is advantageous and I think about that for my AFR gauge (that is why I have an 02 sensor on my 930 euro Row) AEM makes a two bank system so you can switch back/forth and measure the AFR on both sides.