Rennolazine

I tried pulling apart here but it wouldnt budge

Soul Performance

"This guy just put a sock in it"

Pete I just sprayed water all over my desk laughing at that

For those chiming in on this topic, we feel this is a SERIOUSLY underrated mod and a real gamechanger. Professionally documenting this with photos and video, along with putting together a little kit for those that want to do it, is a priority for us and we aim to have this done very soon for those that want to try it. Any photos or explanations of those that have tried this successfully, please post in this thread so we can all reference it moving forwards

Regards,
John Gaydos

BWJ

I was not convinced that just plugging the pipe leading to the passenger compartment would prevent the sound tube from delivering drone noise to the interior of the car. If the flapper valve was still active, intake noise would still be piped into the engine compartment via the tubing path and that noise might be audible inside the car. Also, some of that noise (drone) might be able to penetrate the foam plug I installed since very few things are totally sound proof. Think of someone in a car next to yours cranking their sound system, particularly the bass frequencies. That sound will definitely penetrate your car. Just figured I would eliminate as much of the problem as possible, especially since I would already be in the engine compartment with access to both ends of the sound tube. Unfortunately, I didn't take photos of the process since I really didn't know if it was going to make much of a difference or not. Actual plugging of sound tube was very straight forward. Accessing the engine compartment is more complicated but very doable if you are handy with tools. As far as finding the foam to stuff the tube, it really isn't critical to use the exact same material I did. The important thing is to make sure the material will withstand the heat in the engine compartment and that it will expand once you stuff it in so there are no gaps inside. Also, it should be closed cell foam to resist noise penetration. Think neoprene.

Rennolazine

I need to disconnect the vacuum to that flapper **** asap. Also apparently the 992 gt3 is even worse. Look at the chris harris video “its louder in the car than the 991.2 to offset the wltp restrictions”. This is gonna be required moving forward on all the “opf” cars that sound like *** from the factory. Soul u need to get whipper snapping and ill be happy to help promote this on all my cars moving forward. Gt3 is being conceived as we speak.

BWJ

Also, while it would have been possible to just remove the vacuum hose and use rubber caps on the vacuum line and the flapper valve, there were two problems with this approach. One, would not look OE when finished, Two, without the rubber hose to stabilize the vacuum line, that vacuum line would be free to vibrate and flex which could lead to some premature cracking or other type of damage. Vacuum leaks will most certainly negatively affect your engine's performance and might trigger a CEL. Also, if you try to stabilize that unsupported vacuum line by strapping it down to some other part of the engine compartment, you will put significant strain on the formed plastic tubing it is made out of, which in the long run is not a good idea.

Westcoast

That part of the hose is heat sealed/glued in, normally they are designed to come off at the end of the hose assembly not in the middle, the arrow shows where it will come off.

BWJ

That hose is not glued onto the vacuum line. It will pull off with a bit of wiggling. Best approach is to pull the rubber hose off the flapper valve as shown in the picture (arrow) and then, while holding onto the vacuum line so it won't twist, use a pair of pliers to twist the hose until it will pull off the vacuum line. If you don't remove the hose from the vacuum line, you can't insert the plug as I described.

Westcoast

I would be trying a little closer to home, a close celled foam like Ethafoam, it is everywhere and used in packaging as well, it can be almost any colour, white, red, blue even black. I probably save too much but it is very common place: ethafoam - Bing images

Agreed, a closed cell foam, but not likely neoprene as it would not easily compress then expand into the pipe.

Westcoast

Not trying to challenge you here, but if it pulls off easily at the vacuum valve why not simply use a vacuum cap on the valve and then plug the pipe?

BWJ

Not sure I would use Ethafoam since it is no where near as dense as neoprene. Neoprene (wet suit material or sleeping pads for camping) does expand enough to form a nice tight seal. You just have to cram it into the tube so it already more than fills the space, then let its sponginess insure a perfect seal. There are probably other materials used for sound deadening purposes in cars that could be utilized and I suppose you could also use silicone sealant if you wanted to deal with the mess but I think the foam is the easiest way to do this.

BWJ

See my previous post on that subject. #935

lovetoturn

Great write up BWJ. A benefit for all of us due to your willingness to take the time and just get it done. This has been talked about, but not executed to the level you just discussed. Thanks Again.

And to John at Soul, I bet this is why your results with Helmholtz resonators was so variable and not exactly how you thought they might help with drone. Can't fully get rid of drone via exhaust modifications when part of it originates from the intake side of the engine.

IL_Pete

I did the OAPs and the Valve Controller at the same time a few weeks ago. Wow! I love it, it really transformed the car. I run the Valves fully open most of the time, sometimes I turn them off leaving and entering the neighborhood, especially in the mornings or evenings. Also when I see a police car I sometimes turn them off, no reason to attract unwanted attention in that regard. I had my dealer (who installed both) program Homelink 2 & 3 for On and Off for the Valve Controller, which makes it super easy.

The sound is really great, especially at higher rpms. Also there is a great burble on overruns, and sometimes you get rewarded with a loud crack on an aggressive acceleration followed by a shift. Nothing over the top that sounds artificial, just right.

I am thinking about doing more, to further improve the sound. I don't want it any/much louder (it seems pretty loud already now), but to improve the sportiness of the tone.

Matt at Obsessed Garage posted this today:


OAPs plus the Valved Rear Box from Soul, with the Valves permanently off. It does sound slightly better than just OAPs and the Valve Controller, but I worry about the drone Matt discusses.

I am not conscious of drone with my current setup. (But I have a GTS 4.0 Cayman, not a GT4. Likely the Cabin sound is louder in the GT4, and given that maybe drone is too.)

Soul Team, and others here - what would you suggest? As an alternative to adding the Valved Exhaust, I had also thought about the new Street Headers, and keeping the rear box stock. The demo video of the Street Headers on the Soul Website sounded good, but that was just the Street Headers, with stock OAPs and Rear Box.

Would the Street Headers plus the OAPs and Valve Controller but a lot louder than it is now, with the OAPs, Valve Controller and Stock PSE rear box? Any demo videos of that combination?

Thanks in advance for any inputs!

-Pete

Westcoast

Good point regarding the hose and line, certainly don't want things waving about in there! I would likely have removed the line completely and capped off the connections at each end, this would eliminate the chance of a vacuum leak as well, As for the OEM look, my dealer knows me already, they have seen what I have already done over the years and would simply talk to me if they needed to understand what I had done.

Ethafoam comes in different densities, I have it ranging from quite soft to firmer than Neoprene (which I also have), sound insulation works best when it slows down the sound waves (dependent also on frequency), as the material approaches a solid it can actually act as a conduit for sound, anyway...

A little trial and error never hurt, and you have a good idea here and I appreciate that you shared it with us. I would like to try the foam-in-tube part first to see if that makes enough difference... and hopefully from the cabin side if possible. ​​​​​​​

Bob Z.

That's the exact setup I am going to do with my Spyder, when it arrives in July...already purchased everthing.