How many catalytic converters in boxster? - 986 Forum - The Community for Porsche Boxster & Cayman Owners

bigborian · 07-20-2009, 01:09 PM

when i looked under the car i only saw 2 but i've seen from performance parts places that state they make cat-bypass pipes that bypass the secondary cats which mean that they have primary cats as well. Does the boxster have 4 cats? If so where are the primarys? Would the o2 sensors be affected if I gutted the secondary cats?

mylamb · 07-20-2009, 01:25 PM

It depends on the model year. I believe the older Boxsters had 2. I have a 2001 & it has 4.

mptoledo · 07-20-2009, 03:08 PM

I have a 2001 "s", any idea of how much power(if any) is lost through the cats? I mean we have no smog testing in my part of ohio, so what the hell!!

bigborian · 07-20-2009, 03:46 PM

I have a 99 boxster, ic then i will keept he cats since i need to smog all the time damn cali haha.

mptoledo · 07-20-2009, 07:31 PM

Quote:

Originally Posted by bigborian

I have a 99 boxster, ic then i will keept he cats since i need to smog all the time damn cali haha.

Picked my Box up in Sanfran a month ago. a lot hotter out there than I thought.

I really would like to know what kind of HP gains I would get by taking off my CATs.
I have googled the subject and haven't found anything. My first car was a 1980 mgb limited, thats when i fell in love with convertibles. The first thing I did was to take off the cat and put headers and a HO webber carb. It really pepped up that little engine. I read a thread about a guy who put a supercharger on his car "OHboxter" I think, But that is a lot of $$ and time. I am just trying to squeeze out every bit of power without jeorpardizing my engine.

jwade · 07-20-2009, 08:21 PM

get a set of fabspeed by-pass pipes and a bmc air filter. Removing the secondary cats and the air filter really woke up the car. if you have stock exhaust, you could add theirs too or go to an oem tequipment sport exhaust like mine.

i still have stock headers. removal will cause check engine light to come on and i didn't want to spend the 2300 bucks fabspeed charges for the headers. they really need to come down in price if they want to sell more of those. they are nice though.

have fun. i love my car!!!

mptoledo · 07-21-2009, 05:34 AM

Quote:

Originally Posted by jwade

get a set of fabspeed by-pass pipes and a bmc air filter. Removing the secondary cats and the air filter really woke up the car. if you have stock exhaust, you could add theirs too or go to an oem tequipment sport exhaust like mine.

i still have stock headers. removal will cause check engine light to come on and i didn't want to spend the 2300 bucks fabspeed charges for the headers. they really need to come down in price if they want to sell more of those. they are nice though.

have fun. i love my car!!!

Thanks for the feedback. yes 2400 bucks does suck. I like the check engine light off too, as I'd like to know if something else goes wrong. I will check into the fabspeed by pass.

Do you get the infamous droning sound? Somebody has a thread(i think 2k3_boxster) about installing an aftermarket exaust and his is dyno checking HP before and after to see if porsche has stiemed airflow. His thinking is that Porsche(companY) might have done this to make the 911 look faster. it is a few threads down from this one, It is a very interesting read and hopefully he will be done soon.

I can't see increasing the air flow through your exhaust will do nothing but good things for your car. More HP better MPG, and less heat. Just my thoughts.

Adam · 07-21-2009, 09:08 AM

Your car has two sets of cats. One set is integrated with the manifolds and the other is downstream by the muffler which are probably the ones you saw. The bypass pipes delete the 2nd set of cats by the muffler. Here is a pic of the stock system off the car next to fabspeeds pricey system. Use of the cat delete pipes yield about 5-8hp gain typically and a little more sound.

You don't want to elminate the warmup cats or you'll get those CEL issues. Maxpeed makes a more economical set of headers with cats if you don't feel like dropping $2,300 for just the headers alone. They also offer cat bypass pipes and mufflers. If you talk to them about the whole set I believe they offer you a price break.

http://www.maxspeed-motorsports.com/986exhaustparts.html

mptoledo · 07-21-2009, 05:31 PM

Thanks,

I am just trying to get some ideas of what to do next. Sound means nothing. I would rather have it sound like an original VW bug and fly like a P-turbo. I am looking into superchargers, there was a great thread by ohboxters(or something) who put a supercharger on his car for dirt cheap. but never dyno'd it to see what the real gains were. I think he offed the car since.

Adam · 07-22-2009, 07:41 AM

Quote:

Originally Posted by mptoledo

Thanks,

I am just trying to get some ideas of what to do next. Sound means nothing. I would rather have it sound like an original VW bug and fly like a P-turbo. I am looking into superchargers, there was a great thread by ohboxters(or something) who put a supercharger on his car for dirt cheap. but never dyno'd it to see what the real gains were. I think he offed the car since.

Turbowerx offers a turbo kit that gives the 986 S around 300 at the wheels which is quite an increase over stock or even a TPC supercharger setup. Excellence did a right up on the car and they said it felt similar to the 996 turbo under accel. Here is a link to the guys car and some related links.

http://www.cardomain.com/ride/3226302

mptoledo · 07-22-2009, 09:49 AM

Quote:

Originally Posted by Adam

Turbowerx offers a turbo kit that gives the 986 S around 300 at the wheels which is quite an increase over stock or even a TPC supercharger setup. Excellence did a right up on the car and they said it felt similar to the 996 turbo under accel. Here is a link to the guys car and some related links.

http://www.cardomain.com/ride/3226302

Nice read. I wonder what it does to MPG? Unfortunatley its a little pricey(for me). $8000 is a lot to put into a car I only paid $13k for. I know you get what you pay for. I will do some more research before I do anything. I would really like to do the "IMS" mod if I am going to put any more money into my BOX. Not that my 2001 "S" has a bad ims bearing but why take the chance?

Today or Tomorrow I am going to change the plugs/fuel filter and get the oil/filter done. That should be about it for my 60k tune up except fluids. I did the belt and ignition switch yesterday. Those were pretty easy.

jwade · 07-22-2009, 11:34 AM

Do you get the infamous droning sound? No, not at all with the Tequipment PSE and Fabspeed bypass pipes.

Turbo chargers...superchargers...bla-bla-bla.....I wouldn't do it. Might be fun for a little while, but just too much long-term maintenance.

It's better to swap the engine in it's entirety if you want the best power as the only weak link in the car is not enough torque. More engine cures this as Jake Raby is proving with his Flat 6 innovations. It's expensive though at 15k minimum and like you said, you paid 13k for the car.

As far as exhaust / headers, I looked at Maxspeed too, but just made a judgement call on the Fabspeed pipes and quit there for now. They have a longer track record and aren't made in China.

Turbowerx Headers are the ticket and pretty nice value, but if I went that route, I'd want to reflash my DME with RoW software.

The reflash would elliminate the CEL, but you have to have the PST2 from Porsche to do this. Occaisonally, one will pop up on ebay as Porsche has phased them out, but they are still expensive. They usually come in the form of an IBM laptop with a serial connector.

mptoledo · 07-22-2009, 03:22 PM

Quote:

Originally Posted by jwade

Turbo chargers...superchargers...bla-bla-bla.....I wouldn't do it. Might be fun for a little while, but just too much long-term maintenance.

It's better to swap the engine in it's .

Yeah, but I don't have $26k laying around. I did see a guy puting a corvette engine in his boxster. It is only 2" longer than the stock motor. Now that might be a hoot. I would probably do something in the $2500 to $5000 range. I am pretty tech savy and could do most of it at home. I have mig/wire welders and am decent(not great) at it. No chinese crap, but wouldn't mind doing it in stages. as stated earlier, I would have to do the "ims" swap out, for peace of mind if nothing else before I make that kind of investment.

Of course reality then sets in and with increase in the amount of cops looking to increae revenue in my area, I would probably be stupid to do it. We have the infamous state troopers(ghestapo of ohio), then the sheriffs have been out in force and then we have the city cops who have been total dicks. Even the game warden/park ranger guys have been ticketing people.

vath2001 · 07-22-2009, 04:41 PM

Of course reality then sets in and with increase in the amount of cops looking to increae revenue in my area, I would probably be stupid to do it. We have the infamous state troopers(ghestapo of ohio), then the sheriffs have been out in force and then we have the city cops who have been total dicks. Even the game warden/park ranger guys have been ticketing people.

Got one to top you... we have Toledo City workers writing parking tickets on cars parked in their owners driveway. Oh Yeah! Its called revenue enhancment.

Or BS.

mptoledo · 07-22-2009, 09:12 PM

Quote:

Originally Posted by vath2001

[I]
Got one to top you... we have Toledo City workers writing parking tickets on cars parked in their owners driveway. Oh Yeah! Its called revenue enhancment.

Or BS.

LOL, and that suprised you? Carty is one desperate dude!! Read my screen name( MP Toledo) . I just left toledo 2 months ago, as i can't see how the hell they will survive the death spiral. I loved the city for 10+ years, but the last straw was when Forbes magazine rated the top city to get a job in and toledo took 365th out of 365(dead last)

and with finkbiner cutting the police force I just didn't want to see a great city die!! thats why I moved to the columbus area. No offense to toledo people, but enough was enough, as crime was starting to run out of control. I do miss jenos pizza and packos

bigborian · 07-24-2009, 05:37 AM

So then if the secondary cats are only in there for further filtering of carbon emmissions are there any negative effects from gutting out the secondary cats?

It won't throw off a check engine line cause the o2 sensors are on the primary cats. Most likely i will still pass emmissions as long as i take care of my car make sure it runs clean and keep the primary cats?