secondary cat delete.
 

So im thinking about doing a secondary cat delete on my box. It is a 2.7 liter. has anyone done this? does anyone know of any benefits to this if any? and thoughts aobut the sound? thanks for the opinions :cheers:

Sound? A bit louder
Less weight? +1
Calif smog inspection? Ruh Roh! Not street legal to remove cats. Can you find a lazy/shady inspection station that will let it go? Maybe.

smog could be a drawback but to be honest im not too worried. what about loss of power? I do have a larger diameter intake so would this increase power it at all since it can breathe a little better?

Get the Fabspeed pipes. No regrets whatsoever. Now I would like to get some good quality headers and reflash the dme to RoW.

Don't know how Cali would like that header upgrade though. Tennessee is a great state to live in! No one here knows what a smog test is...

im just going to have a local shop cut me some pipe. I see no need to pay fabspeed 500 dollars for something I got quoted 40 per side... but I had to cut the cats off myself so I guess I pay the price in other ways. :cheers:

there is actually an alternative:
get a set of secondary cats from a junkyard. Now get rid of whatever's inside the cat housing (I leave it up to your imagination on how to do that).
Now you have something which looks totally stock, was very cheap and has the same effect like bypass pipes (more torque)

that was a thought. BUT I found a place that bent pipe for 40 dollars total. So a 500 dollar mod so far cost me 40. Hopefully they will match up well. Ill have it done today, I have a AX tomorrow so we will see. the results.

Is that pipe stainless steel pipe? If not, expect to replace rusted out pipe in short order. :D

Also, did they fabricate the triangular flange on those pipes that mates with the headers like the fabspeed pipes? If so, I'd say you got a very good deal.

Cat bypass pipes:
http://fabspeed.com/986Boxster_13.htm

it would have cost me an extra 50 bux for the triangular flange. but since my box is a 2001 and the bolts holding that whole gettup together are rusted solid. I did not want to bother. I cut the secondary cat out and slid the new pipe over the other luckily the entrance pipe to the secondary cat is 1.5in (or so) and the exit is 1.75 so the whole bypass is just 1.75 and it fits snugly over the 1.5, as far as material... idk whatever the exhaust shop had, do exhaust shops use normal or stainless? IDK. but it isnt polished and it was only 40 bones so ill let it ride. but i do need to pick up some clamps and fix some small leaks.


so in the end if you have the money to burn go ahead with the fabspeed... but if you can DIY and you dont mind DIY then this I would contend is the way to go. :cheers:

Thats a really good deal, after all its just a piece of pipe that doesn't have to cost you 500 bucks unless of course you want a shiney ss piping collecting dirt under your car. Im doing the same on my car next week (that or some straight pipes).
P.S. dont worry about it rusting out on you any time soon, stock piping on boxster is just a alluminized steel too. I had a exhaust shop fabricate a cat-deletes and H pipe for my 928 from alluminized steel and 6 years later - just some surface rust.
Just my 2 cents

Sounds cool. Being that you're in Cali, and not in the Northeast where I am where there's salt thrown all over the road in the winter, you'll prob be just fine with the plain steel pipes. How do you like the extra sound?

al83s- yes it is true that everything under there is rusted... whats another pipe lol. however, I do have some small leaks so i may get it all welded in... not sure but all I do know is i will be testing it tomorrow at the AX.

Boxtaboy- It has been fun so far. easy yet time consuming. makes you appreciate the car (to me anyway) I like the sound so far but i will like it more once it stops leaking. its funny even my OEM exhaust points ar leaking slightly ahha. :cheers:

I added the Fabspeed bypass pipes after installing my modified sport muffler. They really opened up the exhaust note and removed a lot of unnecessary weight. Not sure about extra HP or torque, but well worth the $200 I picked them up for, slightly used.

so after running the new pipes all day... Iam thoroughly impressed. not sure about power or anything like that BUT, the sound is amazing. granted I do have an aftermarket muffler also. very pleased. still working out some leaks but well worth the 40 dollars. :cheers:

You found a shop that would mandrel bend for $40??

You did well my friend. I did the same mod but in 2" stainless so the diameter would match my headers. The flanges in stainless cost me about $80 from a place that can cnc stainless plate, a friend of mine bent the pipe for free, but he has a $50,000 piece of equipment that mandrel bends in his shop, and the install cost me $100 as I couldn't quite get it in there myself without the obligatory leak or two.

I was still happy with $180 as opposed to $500.

You are right, sound is better. Is your's a little more metallic in sound like mine? I quite like it as it sounds more like the air cooled motors now. I do think performance is up marginally too, and the weight saving is never a bad thing.

yes 40 bux for the two pipes, the guy who did it was a real champ he just saw the cats that i removed and eyeballed it. took him maybe 5 minutes and came out with a great fit. Im going to try to seal up the leaks I have myself and if that fails Ill just have them welded in. I know a few welders maybe I can get that done on the cheap but im not sure.

as far as the sound is concerned it does have a more metallic sound and I love it. its aggressive and IMHO Porsche. it brings back memories of lemans races.

180 dollars is not bad at all and personally my cap that I wanted to spend wasnt much lower than that, granted you have higher expectations since you wanted the flange piece. but yes very pleased and excited to drive once again in the morning haha. :cheers:

We're gettin technical here. LOL. I think Daniel R was questioning if the shop bent the pipe in Mandrel fashion for only $40 bucks, or just plain pressure bent the pipes (which would restrict flow):

http://www.bobsmuffler.com/muffler_myths.htm

oh lol my bad. No it isnt mandrel bent that was another consideration for getting wider pipes. to accommodate the loss of diameter. seeing as its only 2.5 coming out of the first cat... the diameter after that as long as its at least that is a non issue.

so just wanted to give a follow up. Ive been able to get everything good to go. my leaks are all sealed up and well I love the sound it is incredible. truly amazing. before it was just mundane, now it has a great metallic sporty sound much like I have said before like a Le Mans car. except now with the leaks holed up even stronger and bolder. :cheers:

Cel??
 

Any problems with check engine light or did you leave the o2 sensors? I have a 97 and think about removing the CATS and replacing with pipes.

The other option would be to holllow out the CATS. Any opinions?

you could hollow out the cats but you would probably get a CEL since (correct me if im wrong) you only have 2 cats... whereas my car has 4 so I just removed the last one on each side. and would get the same effect with putting in pipes...

but for me no check egine light, of course I left the O2s in (that would have lead to a CEL for sure) and also it some got rid of an aweful drone that I had. :cheers:

As long as the sensors are still in place, I dont see why it would effect them. The CAT bypass pipes have threads to put the snesors back in place.

lobo-


1) what kind of aftermarket muffler are you running?

2) can you post any sound clips / video files??

3) you in so cal - I'd love to hear it in PERSON vs a sound file... :) I'm near San Diego.

i've got a pedro muffler and have been thinking about secondary cat delete and like you - i figured i'd just find a muffler shop to cut the cats out... but the fear is - when it's time to smog, you could fail the visual. depends how well the shops know boxsters. some may not know that the car has 4 cars vs only 2...if they don't know what to look for - they may pass you..but if you hae what appeas to be welded custom looking pipes that might be a dead give away...

i like that idea of getting some used ones and then gu tting the cats on them...and then put them back in.... or just gut the ones on your car..how hard would that be? i don't know if you can gut them while they are on the car, or if you'd have to cut them out...gut them..then weld them back in....that might be obvious too..

nice bypass pipes like fabspeed might look OEM enough that they woudl pass the visual... :) just some thoughts..

post up some video!!! wanna hear it!!

im working currently on getting some sound bytes going but unfortunately Ive been very busy moving to a new place.

as far as passing inspections im not too worried. besides it looks like a cat-back system so no one would really know the difference. unless like you said they know boxsters. i just met a neighbor of mine who has a welder so i may just end up welding it in.

the muffler is a deluboz.

i heard bashing on the cats breaks up the insides or using a long piece of metal to go in there and break it up... cant speak out of experience tho.