Headers Only
06-16-2017 | 06:21 PM
#17
Drifting
Joined: Apr 2009
Posts: 2,071
Likes: 156
From: Indiana
Keep in mind that just adding headers does not make an engine breath more fully. If the engine isn't taking in more air, headers aren't going get more out. I'd suggest some kind of loud muffler if loud is what you're going for (and a different muffler isn't going to give you more hp either......contrary to claims from some performance muffler builders.)
06-16-2017 | 06:30 PM
#18
Rennlist Member
Joined: Aug 2006
Posts: 9,051
Likes: 1,781
From: Chicago, IL
I performed the gundo hack on my car, and it's not quiet anymore. It's actually decently loud. So you could do headers and mufflers that are lite and open, and it will sound great and loud.
06-16-2017 | 06:39 PM
#19
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From: Philadelphia, Pennsylvania
Your best bet will likely to be to go to a custom exhaust shop. You will definitely need to run the Oxygen sensors, at the very least the two primary sensors which are responsible for measuring air fuel ratio and relaying the information to the computer to make adjustments as needed.
I would HIGHLY recommend a tune. You are going to change the engines running parameters in a way that the stock tune will not be able to compensate for completely. A tune will better allow you to optimize the injector pulses, ignition timing and other key running features to help improve performance. It will also allow you to turn off the check engine light you'd get by running catless.
It is worth noting that you may see a drastic reduction in low and mid range torque due to the removal of the cats. You can gain some of this back by merging both banks of the exhaust with an x-pipe, but I understand that you want to keep it as simple and light as possible.
Good luck
I would HIGHLY recommend a tune. You are going to change the engines running parameters in a way that the stock tune will not be able to compensate for completely. A tune will better allow you to optimize the injector pulses, ignition timing and other key running features to help improve performance. It will also allow you to turn off the check engine light you'd get by running catless.
It is worth noting that you may see a drastic reduction in low and mid range torque due to the removal of the cats. You can gain some of this back by merging both banks of the exhaust with an x-pipe, but I understand that you want to keep it as simple and light as possible.
Good luck
He is indeed correct that you may want to consider an X-Pipe to merge both sides of the exhaust. This will help you maintain some low and mid-range torque that would otherwise be lost with the setup you were considering. As far as the tune, we have a solution for every 996 aside from the '99 which has a cable driven throttle body. Our tunes can turn off CEL's from a lack of cats and will also take into account the performance components you are running. Ultimately though, a fully custom dyno-tested tune is the way to go if you end up choosing to run full straight pipes from the headers.
Just look around, you can get the desired results much cheaper. First decide what is more important to you, sound or power. That will dictate which items you replace and for what reason.
You don't always have to do the whole kit. With the amount of options out there, you can pick and chose what items you want to replace based on what you are most looking to get out of it.
You don't always have to do the whole kit. With the amount of options out there, you can pick and chose what items you want to replace based on what you are most looking to get out of it.
Deciding what you are ultimately after is the first step in deciding which components to replace. Starting with the headers is a great way to go though, as the header design on the 996 is very inefficient. On the OEM design, the exhaust pulses from each cylinder combine in a way that creates a large amount of turbulence and robs you of power. After the headers, I have a few options for you. You could opt for a Sport Cat X-Pipe with Muffler Bypass pipes, which would leave just the high-flow cats and no muffler, or you could opt for a Catbypass X-Pipe with our Supercup mufflers. Either of these setups would introduce some drone, but since you are looking to rip around on back-road twisties rather than cruise on the highway, it sounds like it'll be OK for your application! Power and sound are headed your way my friend! 
06-16-2017 | 06:50 PM
#23
Thread Starter
Racer
Joined: May 2017
Posts: 322
Likes: 1
From: All Over
Evan - you're the man! Thanks for chiming in here with your valued experience and knowledge
He is indeed correct that you may want to consider an X-Pipe to merge both sides of the exhaust. This will help you maintain some low and mid-range torque that would otherwise be lost with the setup you were considering. As far as the tune, we have a solution for every 996 aside from the '99 which has a cable driven throttle body. Our tunes can turn off CEL's from a lack of cats and will also take into account the performance components you are running. Ultimately though, a fully custom dyno-tested tune is the way to go if you end up choosing to run full straight pipes from the headers.
Again, great advice from Evan! Deciding what you are ultimately after is the first step in deciding which components to replace. Starting with the headers is a great way to go though, as the header design on the 996 is very inefficient. On the OEM design, the exhaust pulses from each cylinder combine in a way that creates a large amount of turbulence and robs you of power. After the headers, I have a few options for you. You could opt for a Sport Cat X-Pipe with Muffler Bypass pipes, which would leave just the high-flow cats and no muffler, or you could opt for a Catbypass X-Pipe with our Supercup mufflers. Either of these setups would introduce some drone, but since you are looking to rip around on back-road twisties rather than cruise on the highway, it sounds like it'll be OK for your application! Power and sound are headed your way my friend!
He is indeed correct that you may want to consider an X-Pipe to merge both sides of the exhaust. This will help you maintain some low and mid-range torque that would otherwise be lost with the setup you were considering. As far as the tune, we have a solution for every 996 aside from the '99 which has a cable driven throttle body. Our tunes can turn off CEL's from a lack of cats and will also take into account the performance components you are running. Ultimately though, a fully custom dyno-tested tune is the way to go if you end up choosing to run full straight pipes from the headers.
Again, great advice from Evan!
Deciding what you are ultimately after is the first step in deciding which components to replace. Starting with the headers is a great way to go though, as the header design on the 996 is very inefficient. On the OEM design, the exhaust pulses from each cylinder combine in a way that creates a large amount of turbulence and robs you of power. After the headers, I have a few options for you. You could opt for a Sport Cat X-Pipe with Muffler Bypass pipes, which would leave just the high-flow cats and no muffler, or you could opt for a Catbypass X-Pipe with our Supercup mufflers. Either of these setups would introduce some drone, but since you are looking to rip around on back-road twisties rather than cruise on the highway, it sounds like it'll be OK for your application! Power and sound are headed your way my friend! Pm sent thanks
06-16-2017 | 07:11 PM
#25
Rennlist Member
Joined: Jul 2014
Posts: 2,032
Likes: 272
From: midwest...near the ocean
Billy Boat N/A Headers, NIB
$1,050 Now $950
Concord, NC
This is a brand new, unused pair of Billy Boat Stainless Headers for 1999-2004 996 Non Turbo cars. Bought for C4s and never used.
*Part Number* FP0R0800
$950 picked up, shipping available ...
See More
Try the Facebook 996 parts group
$1,050 Now $950
Concord, NC
This is a brand new, unused pair of Billy Boat Stainless Headers for 1999-2004 996 Non Turbo cars. Bought for C4s and never used.
*Part Number* FP0R0800
$950 picked up, shipping available ...
See More
Try the Facebook 996 parts group
06-17-2017 | 04:31 AM
#26
Instructor
Joined: Sep 2003
Posts: 221
Likes: 3
From: Seattle, WA
One thing to plan for is the practical certainty that one or more of the bolts which fasten the headers to your heads will snap off upon removal. I recently had mufflers and cats removed with a set of 997S headers ready to install and I changed my mind on the headers because every single exhaust bolt broke as I tried to remove them. I'll wait until I have the engine out to replace the headers as I did not relish the prospect of drilling out the snapped bolts while lying on my back under the car. Lots of threads on this topic here. You might be lucky of course :-)
06-17-2017 | 12:43 PM
#27
Thread Starter
Racer
Joined: May 2017
Posts: 322
Likes: 1
From: All Over
One thing to plan for is the practical certainty that one or more of the bolts which fasten the headers to your heads will snap off upon removal. I recently had mufflers and cats removed with a set of 997S headers ready to install and I changed my mind on the headers because every single exhaust bolt broke as I tried to remove them. I'll wait until I have the engine out to replace the headers as I did not relish the prospect of drilling out the snapped bolts while lying on my back under the car. Lots of threads on this topic here. You might be lucky of course :-)
06-17-2017 | 02:54 PM
#29
Drifting
Joined: Apr 2014
Posts: 2,335
Likes: 25
From: Los Angeles
One thing to plan for is the practical certainty that one or more of the bolts which fasten the headers to your heads will snap off upon removal. I recently had mufflers and cats removed with a set of 997S headers ready to install and I changed my mind on the headers because every single exhaust bolt broke as I tried to remove them. I'll wait until I have the engine out to replace the headers as I did not relish the prospect of drilling out the snapped bolts while lying on my back under the car. Lots of threads on this topic here. You might be lucky of course :-)
06-17-2017 | 03:30 PM
#30
Three Wheelin'
Joined: May 2017
Posts: 1,255
Likes: 614
From: Charleston, SC
Gundo hack if you don't feel like forking over big money, but, I did just install a Billy Boat Engineering exhaust just yesterday, and I'm pretty pleased with the sound over stock and install was really pretty simple. Did it on the ground in the parking garage of my apartment complex. The full kit was about $1,300 I believe from LMPerformance. Only thing that really sucked was it took almost a month to get here.
With that said, I originally bought Agency Power muffler bypass pipes (remove muffler and run open cats), drove it for one single trip, went back in the garage and put all the stock stuff back on and ordered the Billy Boat. Way happier than running open cats, and the exhaust itself didn't really break the bank. Next step will be headers and go piece by piece.
With that said, I originally bought Agency Power muffler bypass pipes (remove muffler and run open cats), drove it for one single trip, went back in the garage and put all the stock stuff back on and ordered the Billy Boat. Way happier than running open cats, and the exhaust itself didn't really break the bank. Next step will be headers and go piece by piece.