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987BS

Exhaust Idea

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Fellow members, I have a question, what is the purpose of the second set of catalytic converters? I'm talking about the ones inside the muffler... and I would appreciate if someone has a picture or drawing of the cayman/boxster muffler cutted in half horizontally. This is because I'm thinking what could happen If the muffler is cutted in half, then have the second set of catalytic converters removed and fit straight pipes instead. I think the exhaust may sound very good, plus less back pressure. What do you all think about it? Thanks in advance!

Alan

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I think you would fail your emissions tests... Perhaps better to buy high flow primary cats and a sports flow exhaust still with cats installed..

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The rear set of cats is supposed to clean up what is leftover from the front cats.

The use of 4 cats started in 2000. 1997-1999 only had 2 cats.

A local 2000 owner recently put in the factory sport exhaust, but he want even more sound. He is going to remove the rear cats and put in a "test pipe" to see if the elimination of the rear cats improves the sound.

Where we live smog inspections on used cars are every 2 years and he just had the inspection. Plus the inspector did not look under the car. On a new car I don't think you need an inspection until the car is something like 4 years old.

I have never seen a 987 muffler/cat cut open.

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The rear set of cats is supposed to clean up what is leftover from the front cats.

The use of 4 cats started in 2000. 1997-1999 only had 2 cats.

A local 2000 owner recently put in the factory sport exhaust, but he want even more sound. He is going to remove the rear cats and put in a "test pipe" to see if the elimination of the rear cats improves the sound.

Where we live smog inspections on used cars are every 2 years and he just had the inspection. Plus the inspector did not look under the car. On a new car I don't think you need an inspection until the car is something like 4 years old.

I have never seen a 987 muffler/cat cut open.

Thanks Toolpants, but I still dont know if I can remove only the secondary cats without modifying the exhaust, because I think the secondary cats are just before the exhaust, not exactly inside them... can you verify this for me please? If they are inside I think I can do it. Removing the primary cats and putting a test pipe is not an option, as I will have a CEL. Lets see if my idea is possible, and if it is, I will certainly do it.

Thanks everyone!

Alan

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When I have looked at a Cayman/987 mufflers I see an integrated unit that is also the catalytic convertor. The cat and muffler are a single part. The parts list has just a single part number. Here is a picture of a 987 exhaust.

So, I do not know how you can do what you want without cutting something. But you could do this on a 986.

post-4-1160084335_thumb.jpg

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When I have looked at a Cayman/987 mufflers I see an integrated unit that is also the catalytic convertor. The cat and muffler are a single part. The parts list has just a single part number. Here is a picture of a 987 exhaust.

So, I do not know how you can do what you want without cutting something. But you could do this on a 986.

Thanks a lot toolpants, I think I'll have to take it to a shop to have it taken a look at. I will post any info as soon as I get time to do that.

Alan

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Not sure why you would want to cut up a 70,000 $ car's exhaust , would it not be simpler to by a techart item or fit the sport exhaust from a cayman that has baffle bypass pipes. Looking on E bay I see there are companies in Germany offering a bypass option on the standard exhaust to give a more sporty sound. I doubt removing the second set of cats will give a significant improvement in performance as the specialist tuners such as Techart/ speedart / 9FF/ RUF etc only seem to suggest 10 hp with a full system including high flow primary cats and performance headers. Wait a few months are there will be a performance exhaust option for the 987 with switchable baffle as used in the 997. Modifications are fine ..but this seems a bit pointless IMHO.

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Not sure why you would want to cut up a 70,000 $ car's exhaust , would it not be simpler to by a techart item or fit the sport exhaust from a cayman that has baffle bypass pipes. Looking on E bay I see there are companies in Germany offering a bypass option on the standard exhaust to give a more sporty sound. I doubt removing the second set of cats will give a significant improvement in performance as the specialist tuners such as Techart/ speedart / 9FF/ RUF etc only seem to suggest 10 hp with a full system including high flow primary cats and performance headers. Wait a few months are there will be a performance exhaust option for the 987 with switchable baffle as used in the 997. Modifications are fine ..but this seems a bit pointless IMHO.

berty987, my goal is not performance, as I stated above, it is sound. I dont wanto to spend more money (I already spent in the car, bought it cash, 20" techart wheels, coilovers, short shifter, got my headlights stolen twice, bought HIDs, etc), so now I just want to spend an extra 200 to have a better exhaust sound... hope this explains a little bit more my situation, with all that money I could've have bought a nice full exhaust, but I'm tired of spending thousands of dollar more into a car that is depreciating day after day, I know I have to pay to play, but maybe I could find cheaper ways to modify the existing exhaust instead of buying aftermarket.

I'll keep you guys posted.

Alan

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Alan,

Take a look at german e bay and search unger porsche auspuh. There is a company offering to modify your exhaust with additinal bypass pipes to give a more sporty sound. If you look at the pics it may give some ideas as to a cheaper and less complicated mod to removing the cats.

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Alan,

Take a look at german e bay and search unger porsche auspuh. There is a company offering to modify your exhaust with additinal bypass pipes to give a more sporty sound. If you look at the pics it may give some ideas as to a cheaper and less complicated mod to removing the cats.

berty987, I tried to find the name you gave me on both, ebay and google, and no matches came up. Also I live in Miami, and I think I will have to ship them my exhaust (?), anyways, thanks and I'll keep looking.

Alan

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Not sure why you would want to cut up a 70,000 $ car's exhaust , would it not be simpler to by a techart item or fit the sport exhaust from a cayman that has baffle bypass pipes. Looking on E bay I see there are companies in Germany offering a bypass option on the standard exhaust to give a more sporty sound. I doubt removing the second set of cats will give a significant improvement in performance as the specialist tuners such as Techart/ speedart / 9FF/ RUF etc only seem to suggest 10 hp with a full system including high flow primary cats and performance headers. Wait a few months are there will be a performance exhaust option for the 987 with switchable baffle as used in the 997. Modifications are fine ..but this seems a bit pointless IMHO.

berty987, my goal is not performance, as I stated above, it is sound. I dont wanto to spend more money (I already spent in the car, bought it cash, 20" techart wheels, coilovers, short shifter, got my headlights stolen twice, bought HIDs, etc), so now I just want to spend an extra 200 to have a better exhaust sound... hope this explains a little bit more my situation, with all that money I could've have bought a nice full exhaust, but I'm tired of spending thousands of dollar more into a car that is depreciating day after day, I know I have to pay to play, but maybe I could find cheaper ways to modify the existing exhaust instead of buying aftermarket.

I'll keep you guys posted.

Alan

BTW how were your headlights stolen, just curious as it is something to think about

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I see from the Milltek web site that they offer two exhaust upgrades for the boxster 987. Both versions are based around the replacement of the manifolds (headers) and the primary cats with a hiflo version. The difference is that one also includes a high flow set of secondary cats in the main muffler. The only benefit of replacing the second set of cats with hi flow items is a more sporty sound , no performance gain. Therefore it suggests that the way to improve performance is to replace the upper part of the system from block to primary cats , the way to make it sound sporty is to work on the rear muffler and the secondary cats. I still think that a small bypass tube on the main muffler would be the simplest way to improve sound , as per the mods I found on e bay.

http://cgi.ebay.co.uk/Porsche-Boxster-2-7-...oQQcmdZViewItem

hope this helps

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I agree with what Berty said above, this is how the 986 pse works and as the emissions test probe is pushed past the bypass tube no problems with emissions and it would only cost a few dollars to carry out :)

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On the 986, even the bypass tubes are downstream of the cats, so doesn't matter how far or short the probe is pushed into the exhaust.

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Guys, I dont know exactly what are the bypass tubes, can someone please explain? I think they are some tubes that run between the section before the secondary cats and the tips... am I right?

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You got a brand new car and had your headlights stolen already? What area in Miami do you live?

Edited by rhregis

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Back to the topic..I beleive the bypass pipes are there to connect the pre muffler to the exhaust tip. The E bay link also has details of the suppliers main shop. You could try dropping thenm an e mail for more info.. ;)

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