Let's talk about cheap exhaust valve mod options!
#1
Track Day
Thread Starter
Let's talk about cheap exhaust valve mod options!
Hey Guys,
are there any options of modding the exhaust valves so they never close? Is it possible to disconnect the valves?
I simply don't want to install any add-on boxes and wiring inside my engine bay.
Thank you!
are there any options of modding the exhaust valves so they never close? Is it possible to disconnect the valves?
I simply don't want to install any add-on boxes and wiring inside my engine bay.
Thank you!
Last edited by GT4Faby; 09-29-2020 at 06:05 AM.
Popular Reply
03-27-2022, 05:45 PM
Rennlist Member
Easy Exhaust Valve Mod - With Adjustability
So I tried the "Wire Full Open" and did not like the slight drone when cruising around town. So I wanted a way to have the exhaust valves close "part way" in the ~1800-3800 rpm range, giving the increased volume desired, yet not the full blast.... and some adjustability to select the desired exhaust level.
I found these for a 6mm shaft (that's what the Valve shaft measures), and black oxide finished for corrosion protection. They cost about $13 for a set of 4, so I ordered a set.
They took about 5 minutes each to install, mainly due to not lifting the car and working up close thus my eyes were taxed. They fit perfectly and allow for significant adjustability in how much valve closure you desire. When the valves pull shut, the split collar stop squarely on the valve mounting bracket.
I set them with approximately 70% valve closure, you will hear a very slight reduction in volume at ~1800 rpm when accelerating, yet you have to be listening for it to notice it, other wise the exhaust note sound smooth and very linear as the rpm increase. No drone, and a perfect increase in exhaust note volume in the 1800-3800 rpm cruising range!
I like this mod and it only cost $13
I found these for a 6mm shaft (that's what the Valve shaft measures), and black oxide finished for corrosion protection. They cost about $13 for a set of 4, so I ordered a set.
They took about 5 minutes each to install, mainly due to not lifting the car and working up close thus my eyes were taxed. They fit perfectly and allow for significant adjustability in how much valve closure you desire. When the valves pull shut, the split collar stop squarely on the valve mounting bracket.
I set them with approximately 70% valve closure, you will hear a very slight reduction in volume at ~1800 rpm when accelerating, yet you have to be listening for it to notice it, other wise the exhaust note sound smooth and very linear as the rpm increase. No drone, and a perfect increase in exhaust note volume in the 1800-3800 rpm cruising range!
I like this mod and it only cost $13
#2
Burning Brakes
Already been discussed extensively in the last months...
2 options
6 mm grub screw inserted in vacuum lines/reatach the lines to valve for OEM look or to body with zipties
use metal wire to kep the valves open (default position when engine off), preventing them to close
2 options
6 mm grub screw inserted in vacuum lines/reatach the lines to valve for OEM look or to body with zipties
use metal wire to kep the valves open (default position when engine off), preventing them to close
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GT4Faby (09-29-2020)
#4
Track Day
Thread Starter
Thank you a lot! I found everything I was searching for.
I'm going to quote all interesting posts for everyone who is searching for this topic:
Solution 2:
I'm going to quote all interesting posts for everyone who is searching for this topic:
The previous description worked great for me! The valves are normally open so when the vacuum lines are removed, they are already open. It is pretty easy to remove the vacuum lines and insert the M6 grub screw even without being on a lift or jackstands. I did it by hand (although on one side it did came off quickly as I was forcing it, and I have a bloody knuckle to show for it!). Suggest that you do it when the car is cold; much easier to touch/feel what you're doing. Enjoy the music.
Ended up doing the vacuum line mod with the grub screws and actually like the sound. There is a hint of resonance between 2-2.5k RPM in certain situations but it doesn’t bother me given that I wanted the car to sound more robust below 4K. And the fact that I only take the GT4 out for spirited drives, usually by myself (my happy place), and don’t care to listen to music while doing so makes it completely acceptable. I believe the next step is Soul over-axle pipes - no other reasons for Soul other than I have buddies that have been very happy with them on other p-cars so figured I’d give it a shot. In the interim, I recommend yanking those vacuum lines, screwing in some M6 grub screws, reconnecting and enjoying more of that sweet n/a engine.
Super easy procedure, didn't require lift , just unplugged the lines with the hand, released a side clamp to have the end at a working reach, screwed the headless screws and inch or so, and plug again.
Don't expect a significant chance, because is very subtle . What I would highlight though is that the car feels less restricted reaching 4000rpm and that "drone" that used to listen passing the 4000rpm doesn't bother me anymore.
Don't expect a significant chance, because is very subtle . What I would highlight though is that the car feels less restricted reaching 4000rpm and that "drone" that used to listen passing the 4000rpm doesn't bother me anymore.
Chiming in to say thanks to the previous posters for mentioning and helping with this mod. I just plugged the each of the valves with a couple M6 grub screws. I can’t quite tell a huge difference honestly, but I feel better now knowing the valves are open all the time.
Since this is the very first time I’ve “worked” on a Porsche it was a little a scary to just start pulling and plugging stuff. If anyone else comes across this thread and hasn’t worked on a P-car before either I thought I’d attach some extra pictures to show exactly where things were located as it wasn’t super clear to a new person like me:
I took off the wheels to do this. It’s not required, but since I didn’t know where or what I was looking for I thought it would help. I only took an additional 10 minutes to pop the tires off and on so I’d still recommend doing so for simplicity sake. Blue arrow indicates where to look for the vacuum lines:
An alternate closer view with the area circled:
Last but not least a close up of everything. Left circle is where you pull the vacuum lines off the exhaust valves, plug with a screw, then put back on. Right is the retaining clip you can undo in order to free more of the vacuum
line to work with.
Since this is the very first time I’ve “worked” on a Porsche it was a little a scary to just start pulling and plugging stuff. If anyone else comes across this thread and hasn’t worked on a P-car before either I thought I’d attach some extra pictures to show exactly where things were located as it wasn’t super clear to a new person like me:
I took off the wheels to do this. It’s not required, but since I didn’t know where or what I was looking for I thought it would help. I only took an additional 10 minutes to pop the tires off and on so I’d still recommend doing so for simplicity sake. Blue arrow indicates where to look for the vacuum lines:
An alternate closer view with the area circled:
Last but not least a close up of everything. Left circle is where you pull the vacuum lines off the exhaust valves, plug with a screw, then put back on. Right is the retaining clip you can undo in order to free more of the vacuum
line to work with.
Solution 2:
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#5
Burning Brakes
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#6
You're right, I was thinking "cheap for a Porsche owner", but my cheap isn't everybodies cheap. Had myself a golf tee mod in mind, did do this myself a decade ago, on BMW when no switches were available yet.
#7
Track Day
Thread Starter
Its not about the pricing point of the control boxes, but the installation requires the engine cover not to be fully closed. (to channel the cable trough)
And in my opinion thats quality wise a CHEAPER solution than removing the valve wires.
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#8
I only wrote CHEAP in the title to get the headline some kind of provocative... Clickbait if you want to call it so.
Its not about the pricing point of the control boxes, but the installation requires the engine cover not to be fully closed. (to channel the cable trough)
And in my opinion thats quality wise a CHEAPER solution than removing the valve wires.
Its not about the pricing point of the control boxes, but the installation requires the engine cover not to be fully closed. (to channel the cable trough)
And in my opinion thats quality wise a CHEAPER solution than removing the valve wires.
#9
Burning Brakes
The Soul valve control module does not require the engine cover to be opened up. It is a different approach than the CG one. With Soul you need to source power from fusebox and tap on the vacuum system on top of transmission. That is the option I chose. Waiting for JCR exhaust to come in (any day now I hope!) to install the module as it is easier to do with exhaust removed. It is also cheaper than the CG one.
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Soul Performance (01-05-2021)
#10
Rennlist Member
Do all of the exhaust valve control units (whether CG, Soul, Akrapovic, JCR) work with the standard exhaust or do some of them require their brand specific exhausts? I'm guessing it should work on OEM exhaust set up too but not sure.
#11
RL Community Team
Rennlist Member
Rennlist Member
If it to control the vacuum operated valve it will be cross compatible...
#12
RL Community Team
Rennlist Member
Rennlist Member
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TXRubicon (06-23-2022)
#14
Burning Brakes
#15
RL Community Team
Rennlist Member
Rennlist Member
For normal driving I have no problem with the stock operation, but when I choose a time for more exhaust noise an external controller allows this flexibility, even if an ECU can turn it on those openings would be mapped, that is not my desire.