Install Review: NHP 200cell cat sections 997.1 C4S
04-05-2014, 01:54 PM
#1
Instructor
Thread Starter
Install Review: NHP 200cell cat sections 997.1 C4S
I decided I wanted to get some more sound out of my stock C4S, so I decided I might as well gain some power as well! I did my research and decided that high flow cat sections were probably the best bang for the buck in terms of realized performance gains and that little bit of extra sound I was looking for.
I contacted Nello from Maxspeed Motorsports about the NHP systems and ended up buying a set from him. Nello is fantastic to work with and easy to communicate with. +1 for Maxspeed.
Anyways onto the install. I drove my car onto ramps and let it cool for a few hours before I got to disassembly. Here are my tips for installing cat pipes onto a 997.1
Tools:
Flat head screwdriver
Flashlight
Socket wrench
u-joint 3/8 socket!!!! This is most important
13mm socket 6pt
12mm socket 6pt
22mm O2 sensor socket
3" extension
6" extension
12mm ratcheting wrench
1) Start by removing the entire air box assembly. I just undid the hose clamp at the throttle body and took the entire assembly out.
- Unplug MAF
- Unplug solenoid for helmholz. A flathead will pop out the metal clip.
- Unplug vacuum line from solenoid. Be gentle, just pull straight down.
- Un click the wire loom for the MAF and solenoid from air box.
- Un click the tube on the right side of the air box as well, attached to ram air port.
The reason for taking off the airbox is to make the O2 sensor wiring easier to get too and easier to put back properly. Worth the 10min to remove air box.
2) Get under car and start un-doing the two clamps that hold the cat section to the muffler section. Take all bolts and nuts out just leave the clamps holding the pipes in place.
3) Undo the 2 spring clamps that are next too the large clamps on each side. Remove the bolt and the clamp from the car.
4) Go on the top side and un-clip the wires to the O2 sensors. I only did one side at a time to make it easier. My recommendation is to remove the wires from the cable runs to make sure they slide right out with the cats. un route the sensor wires to the underside of the car. Leave them installed into the cats.
5) Start on the drivers side and unbolt the three nuts on the cat section. These are 13mm nuts and make sure to use 6pt sockets to not round the nuts off. The studs stay attached to the factory cat section. Remove the factory metal gasket.
6) Move the cat section close to the drivers side to drop the pipe end out of the clamp. Once its out finagle the entire cat section out from the underside of the car.
7) Take your O2 socket and remove the O2 sensors one at a time from the factory cats and reinstall into the NHP. Make sure they are just hand tight.
8) Repeat the process on the passenger side to remove cat and reinstall O2's
9) Install the DRIVERS side cat section first as it is much easier. Insert the pipe end into the pipe clamp but do not tighten. Line up the header and cat and place the NEW gasket in-between and start using the supplied bolts and nuts. The bolts are 13mm heads and should go on the header side while as the 12mm nuts are easier if they are on the CAT side. Tighten accordingly.
10) At this time I ran the O2 wires up to the top side of the engine bay and plugged them into the drivers side connectors. Run the wires into the wire holders and make sure everything is connected properly.
11) Start on the passenger side and finagle the cat section into the engine bay. Line up the pipe and clamp and insert. Also repeat the same process as drivers side with the bolt heads on the header side and nuts on the cat side. These bolts are where the u-joint is a necessity!!
12) After the header to cat bolts are tightened run the O2 wires up to the top of the engine bay and plug in.
13) Reinstall the clamps with bolt heads facing up and the nuts facing the ground.
14) reinstall the spring clamps same as #13
15) Double check all connections to make sure things are tight.
16) Reinstall airbox...make sure the two grommets under the air box are either on the air box or in the chassis. Mine fell out and I had to put them back on the air box bottom.
17) Redo all connections MAF, solenoid, vacuum. Before placing air box back down onto grommets.
18) Reconnect hose clamp and re-snap the connections to the hose and wire holders.
19) Recheck all connections. Move tools out of the way. make sure O2 wires are not near any moving parts.
20) Start car and immediately go to back of car and run your hand around the connections to check for exhaust leaks. If leaky turn off car and retighten bolts in a star pattern.
21) Drive off ramps and enjoy!!!
22) I always like to recheck all my bolts after about 500miles to see if anything loosened up.
Hope this helps. I would've taken pictures but I was filthy ha
I contacted Nello from Maxspeed Motorsports about the NHP systems and ended up buying a set from him. Nello is fantastic to work with and easy to communicate with. +1 for Maxspeed.
Anyways onto the install. I drove my car onto ramps and let it cool for a few hours before I got to disassembly. Here are my tips for installing cat pipes onto a 997.1
Tools:
Flat head screwdriver
Flashlight
Socket wrench
u-joint 3/8 socket!!!! This is most important
13mm socket 6pt
12mm socket 6pt
22mm O2 sensor socket
3" extension
6" extension
12mm ratcheting wrench
1) Start by removing the entire air box assembly. I just undid the hose clamp at the throttle body and took the entire assembly out.
- Unplug MAF
- Unplug solenoid for helmholz. A flathead will pop out the metal clip.
- Unplug vacuum line from solenoid. Be gentle, just pull straight down.
- Un click the wire loom for the MAF and solenoid from air box.
- Un click the tube on the right side of the air box as well, attached to ram air port.
The reason for taking off the airbox is to make the O2 sensor wiring easier to get too and easier to put back properly. Worth the 10min to remove air box.
2) Get under car and start un-doing the two clamps that hold the cat section to the muffler section. Take all bolts and nuts out just leave the clamps holding the pipes in place.
3) Undo the 2 spring clamps that are next too the large clamps on each side. Remove the bolt and the clamp from the car.
4) Go on the top side and un-clip the wires to the O2 sensors. I only did one side at a time to make it easier. My recommendation is to remove the wires from the cable runs to make sure they slide right out with the cats. un route the sensor wires to the underside of the car. Leave them installed into the cats.
5) Start on the drivers side and unbolt the three nuts on the cat section. These are 13mm nuts and make sure to use 6pt sockets to not round the nuts off. The studs stay attached to the factory cat section. Remove the factory metal gasket.
6) Move the cat section close to the drivers side to drop the pipe end out of the clamp. Once its out finagle the entire cat section out from the underside of the car.
7) Take your O2 socket and remove the O2 sensors one at a time from the factory cats and reinstall into the NHP. Make sure they are just hand tight.
8) Repeat the process on the passenger side to remove cat and reinstall O2's
9) Install the DRIVERS side cat section first as it is much easier. Insert the pipe end into the pipe clamp but do not tighten. Line up the header and cat and place the NEW gasket in-between and start using the supplied bolts and nuts. The bolts are 13mm heads and should go on the header side while as the 12mm nuts are easier if they are on the CAT side. Tighten accordingly.
10) At this time I ran the O2 wires up to the top side of the engine bay and plugged them into the drivers side connectors. Run the wires into the wire holders and make sure everything is connected properly.
11) Start on the passenger side and finagle the cat section into the engine bay. Line up the pipe and clamp and insert. Also repeat the same process as drivers side with the bolt heads on the header side and nuts on the cat side. These bolts are where the u-joint is a necessity!!
12) After the header to cat bolts are tightened run the O2 wires up to the top of the engine bay and plug in.
13) Reinstall the clamps with bolt heads facing up and the nuts facing the ground.
14) reinstall the spring clamps same as #13
15) Double check all connections to make sure things are tight.
16) Reinstall airbox...make sure the two grommets under the air box are either on the air box or in the chassis. Mine fell out and I had to put them back on the air box bottom.
17) Redo all connections MAF, solenoid, vacuum. Before placing air box back down onto grommets.
18) Reconnect hose clamp and re-snap the connections to the hose and wire holders.
19) Recheck all connections. Move tools out of the way. make sure O2 wires are not near any moving parts.
20) Start car and immediately go to back of car and run your hand around the connections to check for exhaust leaks. If leaky turn off car and retighten bolts in a star pattern.
21) Drive off ramps and enjoy!!!
22) I always like to recheck all my bolts after about 500miles to see if anything loosened up.
Hope this helps. I would've taken pictures but I was filthy ha
04-06-2014, 10:05 AM
#4
Instructor
Join Date: Jan 2013
Posts: 163
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I did the NHP 200 cell X-Pipe last summer. Nice upgrade. I did feel the extra pep and the sound was slightly increased although not enough for my liking. Putting on the cargraphics sport mufflers as soon as the car gets out of storage.
Nice mod.
Mark
Nice mod.
Mark
04-06-2014, 02:21 PM
#6
Instructor
Thread Starter
So i went for a nice spirited drive in the los altos hills yesterday. All I can say is I think this is the perfect exhaust sound for someone who wants just a little bit more. It seemed to add that slight GT3 like rasp to the exhaust note, but the rasp is NOT annoying at all. Increases the volume slightly and it seems the midrange torque has a great boost in oomph. Cant exactly tell too much in the top end, but the sound and the mid range punch make it definately worth it! Ill try to grab a picture today!
In terms of power increase it sort of feels like when you add an intake to a turbo car. I would guess maybe 10-12whp in top end, and 20ish whp somewhere in the midrange...around 4500 or so.
BTW i have a perfectly tuned butt dyno. hahaha. Ill try and see if I can get a video as well
In terms of power increase it sort of feels like when you add an intake to a turbo car. I would guess maybe 10-12whp in top end, and 20ish whp somewhere in the midrange...around 4500 or so.
BTW i have a perfectly tuned butt dyno. hahaha. Ill try and see if I can get a video as well
Trending Topics
06-13-2020, 07:49 PM
#9
I decided I wanted to get some more sound out of my stock C4S, so I decided I might as well gain some power as well! I did my research and decided that high flow cat sections were probably the best bang for the buck in terms of realized performance gains and that little bit of extra sound I was looking for.
I contacted Nello from Maxspeed Motorsports about the NHP systems and ended up buying a set from him. Nello is fantastic to work with and easy to communicate with. +1 for Maxspeed.
Anyways onto the install. I drove my car onto ramps and let it cool for a few hours before I got to disassembly. Here are my tips for installing cat pipes onto a 997.1
Tools:
Flat head screwdriver
Flashlight
Socket wrench
u-joint 3/8 socket!!!! This is most important
13mm socket 6pt
12mm socket 6pt
22mm O2 sensor socket
3" extension
6" extension
12mm ratcheting wrench
1) Start by removing the entire air box assembly. I just undid the hose clamp at the throttle body and took the entire assembly out.
- Unplug MAF
- Unplug solenoid for helmholz. A flathead will pop out the metal clip.
- Unplug vacuum line from solenoid. Be gentle, just pull straight down.
- Un click the wire loom for the MAF and solenoid from air box.
- Un click the tube on the right side of the air box as well, attached to ram air port.
The reason for taking off the airbox is to make the O2 sensor wiring easier to get too and easier to put back properly. Worth the 10min to remove air box.
2) Get under car and start un-doing the two clamps that hold the cat section to the muffler section. Take all bolts and nuts out just leave the clamps holding the pipes in place.
3) Undo the 2 spring clamps that are next too the large clamps on each side. Remove the bolt and the clamp from the car.
4) Go on the top side and un-clip the wires to the O2 sensors. I only did one side at a time to make it easier. My recommendation is to remove the wires from the cable runs to make sure they slide right out with the cats. un route the sensor wires to the underside of the car. Leave them installed into the cats.
5) Start on the drivers side and unbolt the three nuts on the cat section. These are 13mm nuts and make sure to use 6pt sockets to not round the nuts off. The studs stay attached to the factory cat section. Remove the factory metal gasket.
6) Move the cat section close to the drivers side to drop the pipe end out of the clamp. Once its out finagle the entire cat section out from the underside of the car.
7) Take your O2 socket and remove the O2 sensors one at a time from the factory cats and reinstall into the NHP. Make sure they are just hand tight.
8) Repeat the process on the passenger side to remove cat and reinstall O2's
9) Install the DRIVERS side cat section first as it is much easier. Insert the pipe end into the pipe clamp but do not tighten. Line up the header and cat and place the NEW gasket in-between and start using the supplied bolts and nuts. The bolts are 13mm heads and should go on the header side while as the 12mm nuts are easier if they are on the CAT side. Tighten accordingly.
10) At this time I ran the O2 wires up to the top side of the engine bay and plugged them into the drivers side connectors. Run the wires into the wire holders and make sure everything is connected properly.
11) Start on the passenger side and finagle the cat section into the engine bay. Line up the pipe and clamp and insert. Also repeat the same process as drivers side with the bolt heads on the header side and nuts on the cat side. These bolts are where the u-joint is a necessity!!
12) After the header to cat bolts are tightened run the O2 wires up to the top of the engine bay and plug in.
13) Reinstall the clamps with bolt heads facing up and the nuts facing the ground.
14) reinstall the spring clamps same as #13
15) Double check all connections to make sure things are tight.
16) Reinstall airbox...make sure the two grommets under the air box are either on the air box or in the chassis. Mine fell out and I had to put them back on the air box bottom.
17) Redo all connections MAF, solenoid, vacuum. Before placing air box back down onto grommets.
18) Reconnect hose clamp and re-snap the connections to the hose and wire holders.
19) Recheck all connections. Move tools out of the way. make sure O2 wires are not near any moving parts.
20) Start car and immediately go to back of car and run your hand around the connections to check for exhaust leaks. If leaky turn off car and retighten bolts in a star pattern.
21) Drive off ramps and enjoy!!!
22) I always like to recheck all my bolts after about 500miles to see if anything loosened up.
Hope this helps. I would've taken pictures but I was filthy ha
I contacted Nello from Maxspeed Motorsports about the NHP systems and ended up buying a set from him. Nello is fantastic to work with and easy to communicate with. +1 for Maxspeed.
Anyways onto the install. I drove my car onto ramps and let it cool for a few hours before I got to disassembly. Here are my tips for installing cat pipes onto a 997.1
Tools:
Flat head screwdriver
Flashlight
Socket wrench
u-joint 3/8 socket!!!! This is most important
13mm socket 6pt
12mm socket 6pt
22mm O2 sensor socket
3" extension
6" extension
12mm ratcheting wrench
1) Start by removing the entire air box assembly. I just undid the hose clamp at the throttle body and took the entire assembly out.
- Unplug MAF
- Unplug solenoid for helmholz. A flathead will pop out the metal clip.
- Unplug vacuum line from solenoid. Be gentle, just pull straight down.
- Un click the wire loom for the MAF and solenoid from air box.
- Un click the tube on the right side of the air box as well, attached to ram air port.
The reason for taking off the airbox is to make the O2 sensor wiring easier to get too and easier to put back properly. Worth the 10min to remove air box.
2) Get under car and start un-doing the two clamps that hold the cat section to the muffler section. Take all bolts and nuts out just leave the clamps holding the pipes in place.
3) Undo the 2 spring clamps that are next too the large clamps on each side. Remove the bolt and the clamp from the car.
4) Go on the top side and un-clip the wires to the O2 sensors. I only did one side at a time to make it easier. My recommendation is to remove the wires from the cable runs to make sure they slide right out with the cats. un route the sensor wires to the underside of the car. Leave them installed into the cats.
5) Start on the drivers side and unbolt the three nuts on the cat section. These are 13mm nuts and make sure to use 6pt sockets to not round the nuts off. The studs stay attached to the factory cat section. Remove the factory metal gasket.
6) Move the cat section close to the drivers side to drop the pipe end out of the clamp. Once its out finagle the entire cat section out from the underside of the car.
7) Take your O2 socket and remove the O2 sensors one at a time from the factory cats and reinstall into the NHP. Make sure they are just hand tight.
8) Repeat the process on the passenger side to remove cat and reinstall O2's
9) Install the DRIVERS side cat section first as it is much easier. Insert the pipe end into the pipe clamp but do not tighten. Line up the header and cat and place the NEW gasket in-between and start using the supplied bolts and nuts. The bolts are 13mm heads and should go on the header side while as the 12mm nuts are easier if they are on the CAT side. Tighten accordingly.
10) At this time I ran the O2 wires up to the top side of the engine bay and plugged them into the drivers side connectors. Run the wires into the wire holders and make sure everything is connected properly.
11) Start on the passenger side and finagle the cat section into the engine bay. Line up the pipe and clamp and insert. Also repeat the same process as drivers side with the bolt heads on the header side and nuts on the cat side. These bolts are where the u-joint is a necessity!!
12) After the header to cat bolts are tightened run the O2 wires up to the top of the engine bay and plug in.
13) Reinstall the clamps with bolt heads facing up and the nuts facing the ground.
14) reinstall the spring clamps same as #13
15) Double check all connections to make sure things are tight.
16) Reinstall airbox...make sure the two grommets under the air box are either on the air box or in the chassis. Mine fell out and I had to put them back on the air box bottom.
17) Redo all connections MAF, solenoid, vacuum. Before placing air box back down onto grommets.
18) Reconnect hose clamp and re-snap the connections to the hose and wire holders.
19) Recheck all connections. Move tools out of the way. make sure O2 wires are not near any moving parts.
20) Start car and immediately go to back of car and run your hand around the connections to check for exhaust leaks. If leaky turn off car and retighten bolts in a star pattern.
21) Drive off ramps and enjoy!!!
22) I always like to recheck all my bolts after about 500miles to see if anything loosened up.
Hope this helps. I would've taken pictures but I was filthy ha
This is about 6-7” if extension.
I installed Soul 200 cell cats. 3 broken bolts but getting the rusted nuts out of the socket was the only drama. I will post before / after videos. I am thrilled with the sound!
06-13-2020, 08:21 PM
#10
Rennlist Member
I too recently installed the NHP hi-flow CAT pipes. Although I am liking the extra mid-to-high end response, I don't think it is the sound that I am looking for. I don't think it sound very good (too raspy at low rpm) so I am in the market for aftermarket mufflers to deepen the tone.....
I have a Softronic tune on my car and that's what the Std and Sport mode refers to
I have a Softronic tune on my car and that's what the Std and Sport mode refers to
Last edited by lowbee; 06-16-2020 at 08:33 PM.