Neb

Finally got around to installing these, very easy to do. I left about 1cm of movement to allow some closure and prevent the valve from seizing as suggested by someone above.

for the fellow Canadians, these 1/4 Collars I got on Amazon fits perfectly and is small enough to actually fit inside the 3 bolts if you want.

$20 for 4 of them, arrives in a week.

AZSSMUK 1/4" Shaft Collar Double Split Axle Collar Clamp of Metal Set Screw,4-Pieces

Parki

I installed the collars last week. Positioned them in the middle to leave some room for closing. Happy with the result so far.
Does anybody leave them installed when the car needs to be at your dealers place for a service? Would it affect approved wartanty?

Nick_CT

My dealer even offered to do this mod for me when they loaned me a GTS that was louder than my own and I asked why, so for me anyway it certainly does not affect the warranty.

slilley

The only time I'd remove them before going to the dealer was if I was having problems with the exhaust valve operation! For any other potential problem that would fall under warranty, this collar mod would be no different than running an aftermarket exhaust or OAPs.

I did this collar-mod 800 miles ago now, and the results are just phenomenal! Every drive feels special, and the beautiful sounds of that glorious flat-6 make me want to run the engine continuously between 4K and 7K. When the roads are empty, driving under an overpass or in a tunnel is intoxicating.

I can see where some might find it too loud, but to me it's perfect. And it completely eliminates the annoying switchover from electric-car-silent-mode below 4K to raucous above 4K. For the record, I also have Akra OAPs - that was the first exhaust mod I tried (ran 1,000 miles like this), followed by wiring the exhaust open (250 miles like this) - but this collar mod is "just right" because it eliminates most of the drone from the exhaust being open 100% below 3K rpms.

greengobln

So after talking to the folks from global industrial they realised that I was sent the wrong ones, the fully refunded me super service. I ordered the one from Amazon but they only have one at a time. I received and install took 2 minutes obviously when you have the right ones it's super easy lol. Now I have to wait for the Amazon seller to restock another one lol

Reedy

My turn.I picked up some 6mm stainless steel collars from a local widget store. They cost like $50 but a Cargraphic controller costs $500 so i'm ok with the experiment.

My OEM exhaust isn't on the car at the moment so a test fit was simple. These ones clear the bolts easily enough but the challenge is clearing the rolled steel bracket. It makes it hard to get an allen key onto it when they are sitting flush, so leaving a small gap and allowing the valves to actuate a small amount is probably best.
(Note the exhaust is sitting upside down in this picture)


My Silenced JCR race pipe was arguably even easier because they have a flat surface, and they are also inverted compared to OEM so the collars just fall right down flush with the flange and are very easy to tighten in this position. No play in the valves but I am not sure whether they are likely to rattle. It's late and pouring rain here at the moment so ill take it for a test drive on the weekend and decide whether to keep them. I've put the gopro under the car and played with the PSE button and they don't move at all with this setup.

Reedy

Took the car for a bit of a drive and I'd say with the JCR exhaust the difference is fairly small, especially from inside the car. To me this is a no brainer with the standard exhaust but with the silenced JCR it's not life changing.
I think ill go back to normal operation because the quiet mode is handy for early morning cold starts. Maybe some kind of middle ground where you don't quite let the valves close all the way would be a good option with this setup. The beauty of having them installed now is I can just slide them up and down the shaft to adjust accordingly.
Installation was a bit of a fiddle but at least adjustments can be done with the car on the ground.

Dana Itani

Hi, I managed to unclip the hose but can't figure out how to unplug it. Do I just pull on it hard or I need to release something?

I have the 2022 model and the dealer told me for legal reasons this year is actually lower sound than prior year of 4.0

slilley

@Dana Itani I believe your dealer is incorrect: there's been no change that I'm aware of to the exhaust in the 2022 models compared to the previous years. If you want to remove the exhaust vacuum line, you just pull hard on it. ("That's what she said!" -Michael Scott ) But then you also need to cap the vacuum lines and zip-tie them somewhere so they aren't flapping around. Personally, I think it's probably just easier to wire them open full time than to pull the vacuum lines - but I still prefer the exhaust collar mod option because it does eliminate some of the drone at low RPMs from having the exhaust open all the time!

Speaking of exhaust collar mods, here's a video a friend's son took of us last weekend on a back-road tour through the nearby countryside in Oley PA. I'm in the silver CGTS4.0, directly behind the blue 718. You can see/hear me at the 13-second mark. When I saw my friend's son on the side of the road with his camera, I quickly downshifted so he'd get an audible treat for his effort (yea for PDK! ). If the embedded video doesn't work below, just click on the "Watch on YouTube" at the bottom-left or bottom-right corner of the video window.

coldfire

I just recently tried this out on my Spyder. For you fellow Canadians looking for a local distributor that has a stainless steel option, I ordered these and they fit: https://www.fastenal.ca/sku/34486?pm=28478&catId=603515

Install was easier than I expected. I didn't even lift the car up, just laid on the ground to access. The clamps are a bit fiddly to handle because the set screws are small, but if you have a small screwdriver/wrench it's not too bad. I stacked 2 of the collars which covers about half of the valve shaft.

After an initial drive, thoughts so far:

• Where I set the collars really reduces the sound delta between PSE on/off. The abrupt transition while driving is almost gone now, a much smoother transition. But there's still enough valve closing that I can tell the difference at idle/low speeds when I turn PSE off.
• This almost seems like how it should have come stock. Enough of a difference on/off, but no weird abrupt transition and you can actually hear some engine character in that valve closed range 2k-5k rpm. No real increase in drone.
• This of course does nothing to change the "tone" of the stock exhaust. Ultimately if that doesn't match the character you expect from the car (I'm in that camp), this won't really change anything. Even though I like this and think it's how the car should have come with this OEM exhaust, I'll likely still go to an aftermarket system with a merged (x-pipe) path.

Cmcdaniel993

I ordered the McMaster - Carr 6mm Shaft Collars. Installation was simple and they have surprising grip. I bought 4 additional cheap collars from amazon thinking I would need to stack them to avoid slippage when the valves continue to open and close. After 3 weeks, no slippage, so no need for additional collars.

On one hand, they are overpriced when paying $56 / 2 ... and on the other hand, this is simply the cheapest and most effective exhaust mod that increases volume and tone, while reducing drone. (when installing at the halfway point to allow partial close of the valves at the ~2-3k range) Im not even sure if I need replacement OAP's now.

So... selling my new Cargraphic Valve Controller that I purchased from Supreme Power earlier this year... never installed. $350 https://rennlist.com/forums/market/1303823

elevensheep

Thanks for the detailed descriptions

Just installed the collars, and it made a very substantial improvement to the sound of my Spyder.

I have left roughly a 5mm gap between top of the collar and the base of the valve, and I’d say the exhaust note is now just about perfect.

pdxmotorhead

Its also probably good to allow some movement to keep it from getting stuck with age.. ??

snrubel

Possibly this is a dumb question, or has already been asked, but is there anyone on here that knows whether restricting the range of movement on these actuators has any long term negative affect on their operation, or on some other system?

StormRune

In old 911 threads I've been in, I recall hearing of the valves getting stuck or sticky when the actuators are completely unplugged and never moving for a lot a miles. When someone tries to reconnect them (changes their mind or a new owner), there's been a small handful of reports of them being stuck or sticky, as best I recall. Of course, the materials being used probably just keep getting better so I don't know if this is an issue any more.

In some of the posts earlier, you'll see some of us mentioning we've left some about 5mm of play on the valve both to reduce drone in that mid-range snd with the added benefit of making sure the valve moves some just in case sticking might be a problem. I think you'll find you don't need it held totally open to get the improved sound.

As to long term negative effects, the valve is built to sit in the exhaust flow so sitting modestly closed shouldn't do it any harm. I doubt the modest change in engine back pressure in that range when max flow isn't occurring - roughly half of total RPM - could present any issues for the engine. Even when its fully "closed" it's not a perfect seal. I'm usually super-cautious about doing potentially harmful things to my cars, but with this I decided any risks were very unlikely.