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UPDATE: Don't bother popping the lever ball off the socket because you'll end up with valves that flop in the breeze and incessantly rattle. The valves themselves have no spring tension. That is provided by the actuator.
But I did find that the hoses pull off the actuators very easily and I just plugged them with a threaded 10mm bolt/washer and tied them up to the cross bracing. Now time to drive and see what I get. If I still get that phony scream at 4K RPM I'll know it's the symposer and it'll be next on the hit list.
UPDATE: Don't bother popping the lever ball off the socket because you'll end up with valves that flop in the breeze and incessantly rattle. The valves themselves have no spring tension. That is provided by the actuator.
But I did find that the hoses pull off the actuators very easily and I just plugged them with a threaded 10mm bolt/washer and tied them up to the cross bracing. Now time to drive and see what I get. If I still get that phony scream at 4K RPM I'll know it's the symposer and it'll be next on the hit list.
This might sound crazy...but on the last 2 GTS 4.0s I have owned, I have removed the valve actuator from the vehicle completely (three 8mm nuts), plugged the vacuum line, and used some thick metal wire to hold the valves in the 'open' position. It has worked great on both applications. I am happy to take photos and share more if you are interested.
Last edited by greenGTS; 02-11-2023 at 07:22 PM.
Reason: quote
I think I've finally achieved the best result possible (to my ears) given the hardware I've got. Mind you, I won't ever spend $5K for an aftermarket rear box so I had to experiment with the stock rear section with and without Akrapovic OAPs.
Initially, I tried the collars with stock OAP's and was unable to dial out ALL of the phoniness of the computer controlled valving without positioning them to essentially keep the valves open all the time so I took them off. I wanted a throatier sound as well, and that's why I bought a set of Akra OAPs from a Rennlister. They delivered exactly what I was looking for as far as tone. But I still had that silly artificial nonsense that the computer forces on you at 4K RPM. I absolutely hated that.
What I've settled on is the Akra OAP's and disconnected/plugged vacuum lines to the actuators. While this setup is slightly louder than I wish it were as I roll around town at slow speeds, it sounds awesome most of the time and there is ZERO shenanigans at 4K RPM, which is the part I was trying hardest to deal with. That instantaneous scream that was almost entirely non-throttle position related drove me crazy because it was so inorganic. Totally unnatural. Nothing about it felt/sounded correct. Well, now I just have a little screamer all the time and that's ok with me. It's not obnoxious. Idle sound is decent. And it's the same note ALL THE TIME. The way most exhaust systems are. Nice to finally have the same note all the way through the entire RPM range. Hope this helps some of you achieve something better than stock without breaking the bank.
The brace I secured the loose vacuum line to has a little groove machined in it that the line fit nicely into. Looks a little hackerish but I wanted to keep everything there and accessible in the event I need to return it to factory.
If you have your valves held open then you have no reason to activate PSE button . . . if you do not activate PSE then your sound symposer will not be activated.
. . . Initially, I tried the collars with stock OAP's and was unable to dial out ALL of the phoniness of the computer controlled valving without positioning them to essentially keep the valves open all the time so I took them off. . . What I've settled on is the Akra OAP's and disconnected/plugged vacuum lines to the actuators.
You did not like the shaft collars because the valves were held open all of the time, but you then went and unplugged the vacuum lines to the valves . . . which holds the valves open all of the time. Why not just put the shaft collars on, instead of all that work to unplug and tie the vacuum lines under your car??? Am I missing something here???
You did not like the shaft collars because the valves were held open all of the time, but you then went and unplugged the vacuum lines to the valves . . . which holds the valves open all of the time. Why not just put the shaft collars on, instead of all that work to unplug and tie the vacuum lines under your car??? Am I missing something here???
Avera
Maybe. I never had them positioned so that the valves didn't actuate at all because I wanted to see if I could achieve something I could live with at less than wide open. I couldn't. There was always that silly 4000 RPM dance.
And to be honest, for those who want the valves wide open all the time it's easier to unplug the vacuum lines and tie strap them up than it was to 1. get those damn collars to secure onto the shaft, and 2. not bang into the actuator nuts making an audible clanking noise.
Are you telling me that the only thing that PSE does is control a plastic tube in between my engine compartment and the cabin? Lol. I hope not.
Last edited by SpyderSenseOC; 02-11-2023 at 09:23 PM.
Maybe. I never had them positioned so that the valves didn't actuate at all because I wanted to see if I could achieve something I could live with at less than wide open. I couldn't. There was always that silly 4000 RPM dance.
And to be honest, for those who want the valves wide open all the time it's easier to unplug the vacuum lines and tie strap them up than it was to 1. get those damn collars to secure onto the shaft, and 2. not bang into the actuator nuts making an audible clanking noise.
Are you telling me that the only thing that PSE does is control a plastic tube in between my engine compartment and the cabin? Lol. I hope not.
I cannot imagine how it is easier to unplug the vacuum lines and do all that tying up with zip ties than it is to pop on shaft collars? Takes about 5 minutes and you do not even have to lift the car to get them on.
Not sure about the 'banging' you reference with shaft collars, as I have never had any banging. Perhaps your shaft collars are bigger than the ones I utilize?
I am not saying all the PSE does is control the sound symposer. What I am sayin is that once you hold your valves open (by any method), then all the PSE does is control the sound symposer. So, if you hold your valves open there is no reason to activate the PSE button unless you want to activate the sound symposer. If not, do not activate the PSE button . . . no need to plug or disconnect the sound symposer.
I cannot imagine how it is easier to unplug the vacuum lines and do all that tying up with zip ties than it is to pop on shaft collars? Takes about 5 minutes and you do not even have to lift the car to get them on.
Not sure about the 'banging' you reference with shaft collars, as I have never had any banging. Perhaps your shaft collars are bigger than the ones I utilize?
I am not saying all the PSE does is control the sound symposer. What I am sayin is that once you hold your valves open (by any method), then all the PSE does is control the sound symposer. So, if you hold your valves open there is no reason to activate the PSE button unless you want to activate the sound symposer. If not, do not activate the PSE button . . . no need to plug or disconnect the sound symposer.
Avera
Well, tugging on a vacuum line and slapping on three zip ties is easier than wrestling with those collars. I've installed the collars twice, too. Neither is difficult, but I did find installing the collars to be more tedious. Both require jacking the car up six inches or so, so I consider that part a wash.
The banging I mention was unavoidable contact of the collars to the mounting nuts if the collars were positioned too far away from the actuator. And that's due to the fact that the actuator shaft doesn't move in and out of the actuator in a straight manner. The lever action of the valve causes the shaft to move laterally as it enters the actuator body, thereby shoving my Amazon collars into the mounting nuts causing the metal on metal clank. The further away from the actuator the collar is, the more deflection. It's possible that different collars have different radiuses and some might not experience the clank while others do. I don't know.
Your last point is well taken. I'll have to run it through the paces with the button on and off to see if I can detect any difference.
Last edited by SpyderSenseOC; 02-11-2023 at 10:38 PM.
A few observations. After putting a few miles on it I'm pretty sure that disabling the valves entirely while running only the Akra OAPs resulted in a situation where the car was just a tad too loud at times when I didn't want it to be. Sitting at idle there was more tubbiness/farting than I prefer. My ideal situation is pretty quiet until about 2K RPM and then increased volume thereafter. Like my C63. So, I reinstalled the vacuum hoses and the collars, but I put the collars much closer to the valves than I had them the first time. Meaning the valves are close to wide open all the time, but not quite. I'm hoping this creates a situation where that silly 4K scream sounds like a more gradual transition and more throttle related rather than algorithm based. I cannot live with quiet, quiet, quiet, 4K, waaaahhh!
That PSE button with the actuators disabled? I could tell zero difference turning it on or off while cruising under varied loads. Couldn't tell if it was doing anything or not. If it was, I couldn't hear it. Time to drive it again and see what the collar adjustment accomplished.
A few observations. After putting a few miles on it I'm pretty sure that disabling the valves entirely while running only the Akra OAPs resulted in a situation where the car was just a tad too loud at times when I didn't want it to be. Sitting at idle there was more tubbiness/farting than I prefer. My ideal situation is pretty quiet until about 2K RPM and then increased volume thereafter. Like my C63. So, I reinstalled the vacuum hoses and the collars, but I put the collars much closer to the valves than I had them the first time. Meaning the valves are close to wide open all the time, but not quite. I'm hoping this creates a situation where that silly 4K scream sounds like a more gradual transition and more throttle related rather than algorithm based. I cannot live with quiet, quiet, quiet, 4K, waaaahhh!
That PSE button with the actuators disabled? I could tell zero difference turning it on or off while cruising under varied loads. Couldn't tell if it was doing anything or not. If it was, I couldn't hear it. Time to drive it again and see what the collar adjustment accomplished.
Your description is pretty much what I was after. I felt I was able to get it so the open / close transition was pretty much gone (admittedly I didn't have the OAP's you have which likely amplify the sound). At that setting, in town with PSE operational I found it perfectly civil. In my case, the collars were slid down to the bottom (near the nubby on the plunger) and allowed to hit the nuts on the valves. I never noticed a clank or sound with that setup. They were also still tight after a month like that (hitting).
I use a 6" rule and measure the distance from the bottom of the Collar to the underside of the Actuator Mount. The position I like best has this distance at 18mm.
I set the collar position and measure COLD.
Your desired position may be different, as there are probably slight variations in manufacturing dimensions, and your desired exhaust level will be unique to your tastes. I have used only one Collar per side, and have experienced no slipping of the collar,
You might have to try a few different Collar positions until you get what sound best to you. That is the beauty of the collar mod - it's adjustable!
Your description is pretty much what I was after. I felt I was able to get it so the open / close transition was pretty much gone (admittedly I didn't have the OAP's you have which likely amplify the sound). At that setting, in town with PSE operational I found it perfectly civil. In my case, the collars were slid down to the bottom (near the nubby on the plunger) and allowed to hit the nuts on the valves. I never noticed a clank or sound with that setup. They were also still tight after a month like that (hitting).
I think the clanking I've referenced is due to the collar glancing off the nut on its way to the base of the actuator. If the collars are set far away from the actuators (like you describe) you are probably getting a direct hit of the collar onto the nut and the lever action stops there, so no clank. I'll report back after I drive it again.
I wonder if there is a device we can install inline on the vacuum hoses that would slow down the actuation process. Like a clutch slave delay valve does on a lot of the BMW's and other later model manual transmission cars. Or maybe we can put a stronger spring in the actuator itself to slow that process down a bit? Or maybe some type of vacuum line reducer with a smaller inside orifice. It's the instantaneousness of that 4K RPM change that chaps me. Something to think about.
Last edited by SpyderSenseOC; 02-17-2023 at 08:36 PM.
I have had my Spyder for 800 miles now and have not tried to go beyond 5k but frankly I can't tell the difference between PSE on/off so far. As this thread suggests a significant improvement below 4k with plug or wire , being a non DIY and has never done any mods on any cars I want to give valve wiring a try as it seems the lowest risk option.
May I ask (sorry if sound silly):
1. Is there a valve on both sides that needs to be wired?
2. Do I need to PSE button on or off once valve(s) wired? Does it matter either way? Can I damage anything by having the PSE status either way?
3. Does valve always open affect gas mileage?
I DIY installed Flat6 OAPs on my '22 Spyder, and it came with plugs for the valve vacuum lines. I chose not to use them but didn't throw them out either.
1. Yes
2. Wiring the valves open makes this moot. But my understanding is that switching to valves open activates the sound symposer which many dislike. If that's true, it's better to leave the switch in the closed position.
3. No, but Auto start/stop does improve it because it activates cylinder deactivation, which 99% of owners don't use. With my OAPs I get horrible drone when deactivation kicks in. Someone else said it's like being inside a tuba and I agree.
First mod on the car on day #2 of ownership was to add the exhaust collars, and since Im in the "breakin phase", it has made the experience 10X better.
Well worth the 20-30 mins this took me. I will be installing the AKRA OAP's next week.
02-11-2023, 05:51 PM
