All You Need to Know About Downpipes
04-23-2010, 10:44 PM
#126
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Ok so I've had the synapse catless for a couple months now. Absolutely love it and now that the muffler has been removed...GREAT SOUND!!!
I only really have one question to ask and it's not to any of the members it's to GM...are you f'n serious...2 cats???? That along with the plastic endtanks on the stock fmic have got to be the dumbest things I've ever seen on a car that's supposed to be a "sports" car. Blew up my stock fmic in less than 1000 miles, GM replaced the first one...the second one got cashed at 1500...that one got replaced by the synapse fmic. No problems since and oh lets see, I've actually tuned the car now...first 2 were ko'd by stock boost levels.
I only really have one question to ask and it's not to any of the members it's to GM...are you f'n serious...2 cats???? That along with the plastic endtanks on the stock fmic have got to be the dumbest things I've ever seen on a car that's supposed to be a "sports" car. Blew up my stock fmic in less than 1000 miles, GM replaced the first one...the second one got cashed at 1500...that one got replaced by the synapse fmic. No problems since and oh lets see, I've actually tuned the car now...first 2 were ko'd by stock boost levels.
04-24-2010, 04:22 PM
#127
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The reason there are two cats is so they can meet strict emmisions standards and the reason the downpipe dips down a bit for where the O2 sensor is, is so that the flow going past the O2 sensor is smooth (atleast that's the only reason I can think off) not the greatest for performance but that's how it needed to be done.
As for the plastic end tanks on the IC, I agree it's not the strongest/best flowing thing but it's cost effiecient and almost all cars that are turboed have IC's with plastic end tanks.
As for the plastic end tanks on the IC, I agree it's not the strongest/best flowing thing but it's cost effiecient and almost all cars that are turboed have IC's with plastic end tanks.
05-20-2010, 01:40 AM
#128
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Well this has def been a good read. Still unable to make my decision lmfao. Think I'm just going to go catless and get the Trifecta tune. F the warranty. Haven't had any problems with the car.
05-20-2010, 11:09 AM
#131
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05-20-2010, 12:41 PM
#132
You cannot have a header and a downpipe/headpipe;
Either the term headpipe or downpipe are used (interchangeably) to describe the piece of bent pipe which bolts up directly to the exhaust manifold, and usually connects to the catalytic converter - so if you have a header you are (99% of the time) replacing both the headpipe/downpipe as well as the factory exhaust manifold.
If you have a "header" (and I use the term loosely) which needs connect to the stock pipe inforont of the cat, then your header is essentially an overglorified exhaust manifold; real headers connect directly to the head, and are no less that aprox 24-36" long
Since I do not know what any headers used on the 2.2 or LSJ engine look like, I am attaching two pictures of real headers made for the precursor to the Ecotec;
As you can see by their size, there would be zero need for piping behind this header, and infront of the stock catalytic converter location... assuming you're running one
nuff said!?
Last edited by soundjunky; 05-20-2010 at 01:01 PM. Reason: small brain fart pertaining to the 1990-1991 GM 'LD2' headpipe and just about all other applications
05-21-2010, 08:20 PM
#133
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hmmm, two posts, and no one said it??!
You cannot have a header and a downpipe/headpipe;
Either the term headpipe or downpipe are used (interchangeably) to describe the piece of bent pipe which bolts up directly to the exhaust manifold, and usually connects to the catalytic converter - so if you have a header you are (99% of the time) replacing both the headpipe/downpipe as well as the factory exhaust manifold.
If you have a "header" (and I use the term loosely) which needs connect to the stock pipe inforont of the cat, then your header is essentially an overglorified exhaust manifold; real headers connect directly to the head, and are no less that aprox 24-36" long
Since I do not know what any headers used on the 2.2 or LSJ engine look like, I am attaching two pictures of real headers made for the precursor to the Ecotec;
As you can see by their size, there would be zero need for piping behind this header, and infront of the stock catalytic converter location... assuming you're running one
nuff said!?
You cannot have a header and a downpipe/headpipe;
Either the term headpipe or downpipe are used (interchangeably) to describe the piece of bent pipe which bolts up directly to the exhaust manifold, and usually connects to the catalytic converter - so if you have a header you are (99% of the time) replacing both the headpipe/downpipe as well as the factory exhaust manifold.
If you have a "header" (and I use the term loosely) which needs connect to the stock pipe inforont of the cat, then your header is essentially an overglorified exhaust manifold; real headers connect directly to the head, and are no less that aprox 24-36" long
Since I do not know what any headers used on the 2.2 or LSJ engine look like, I am attaching two pictures of real headers made for the precursor to the Ecotec;
As you can see by their size, there would be zero need for piping behind this header, and infront of the stock catalytic converter location... assuming you're running one
nuff said!?
05-21-2010, 09:18 PM
#135
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Get it cleared at the dealer if you want. Buy a tool that allows you to clear codes. Could try disconnecting your battery and then reconnecting it and starting the car and it might work as well.
05-21-2010, 11:41 PM
#136
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Sorry everyone for posting the question in the lnf place, but no one anwsered in the lsj one.
05-24-2010, 01:37 AM
#138
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Has anyone had any experience with the MPx downpipe? Looking to get a catless. The code will be cleared if necessary. Just can't decide who to go with. Looking at either MPx or ZZP.
05-28-2010, 07:57 AM
#139
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Just recieved my ZZP Catless in the mail! It didn't come with new gaskets, so should I buy new ones or just see what the old ones look like and reuse them? The parts guy at the dealership said it doesn't say to replace them upon removing or changing the downpipe so I don't know what I should do...
05-28-2010, 08:27 AM
#140
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Oh, and no matter what ANYONE else says, a catless downpipe with stock catback sounds like heaven....
I will do a video when I can.
05-28-2010, 10:36 AM
#142
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Yes, I just got a catless MPx downpipe installed. It is a VERY high quality piece. The welds are fantastic and it has many options. It's about 15 lbs lighter than stock, too.
Oh, and no matter what ANYONE else says, a catless downpipe with stock catback sounds like heaven....
I will do a video when I can.
Oh, and no matter what ANYONE else says, a catless downpipe with stock catback sounds like heaven....
I will do a video when I can.
05-28-2010, 10:48 AM
#143
Just recieved my ZZP Catless in the mail! It didn't come with new gaskets, so should I buy new ones or just see what the old ones look like and reuse them? The parts guy at the dealership said it doesn't say to replace them upon removing or changing the downpipe so I don't know what I should do...
05-28-2010, 10:29 PM
#145
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just have a quick question about downpipes.
i have always been told that not having a cat in your exhaust will eventually premature failure in the exhuast valves. i have been told this by some very credible people and it really makes me wanted to get a DP with a cat. however i really like the sound of the catless. any answers?
i have always been told that not having a cat in your exhaust will eventually premature failure in the exhuast valves. i have been told this by some very credible people and it really makes me wanted to get a DP with a cat. however i really like the sound of the catless. any answers?
05-30-2010, 11:13 AM
#147
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Some people dont like the design of the o2 bung for the ZZP downpipe. It is however cheaper then the Hahn one. I'd recommend giving the MPx (ModernPerformance) Downpipe a look. It's cheaper then both right now, and I helped a friend install his and it looked like a good downpipe.
05-30-2010, 01:52 PM
#148
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IMO all the downpipes are virtually the same especially if you are going with catless. If your going catless I'm going to think you are getting your car tuned and you can disable any catalytic convertor codes. I have the MPx Catless downpipe on me and it is pretty amazing. The HAHN and ZZP seem to be at or about the same quality and piece
