Can you cold start RS5 with valves closed?

[spa]

I know if set in comfort it will close them up after the initial start up but is there a way to have them close before you start. I know opposite of what most people ask for just trying to keep the neighbors from organizing a lynching party for me.

[superswiss]

I don't believe so. The valves are controlled by a vaccum and in absence of it they are open, so upon cold start the vacuum pump has to first create a vacuum to close the valves.

[cmoore86]

Are you talking about the cold startup sound or the valves on the exhaust? If its the valves on the exhaust, then unless you turning the car on and cycle through the drive select modes and get back into dynamic before actually starting the car, then the valves are closed. The extra loud cold start up is controlled within the CPU. I believe the only way would be to disable in vag-com (if even possible)

@superswiss - can you disable cold start up with vag-com? And if so, would that do anything bad for the car?

[LINDW4LL]

He's only asking about the valves operation.

[spa]

I'm talking exactly what superswiss describes. Thanks for the info. Might start it with garage door closed to muffle that intial sound. I bought the car with non sport exhaust and I just got exhaust installed and they also replaced the resonators of the downpipes with a x pipe, I'm wondering if putting the stock resonators back in the downpipes would ease the cold start up sounds. I have never heard a stock sport rs5 cold start so I really have no frame of reference as my non-sport was so docile on start up. Thanks!

[Ducman5]

Has anyone found a solution to this? I also would like to have the valves closed on cold start-up. I see there are independent remote controls for valves but without vacuum I'm afraid these would not accomplish the goal. Need to have the option for a quiet start. If I can't find one I may have to go back to stock exhaust.

Thanks

[cmoore86]

Unfortunately I still say that the exhaust valves are closed for cold start. If you do a cold start up cycle though the exhaust modes in drive select until you get back to dynamic. Exhaust should get louder. At least that is what mine does every time. Unless I am misunderstanding the question...

[Ducman5]

[QUOTE=cmoore86;12489581]Unfortunately I still say that the exhaust valves are closed for cold start. If you do a cold start up cycle though the exhaust modes in drive select until you get back to dynamic. Exhaust should get louder. At least that is what mine does every time. Unless I am misunderstanding the question...[/QUOTE

If I cold start in comfort the car will start with valves open and close shortly after. If I start in dynamic they are open and stay open.

[spa]

@Ducman5
I too had your problem, with way to crazy coldstarts, the valve remote control box won't help this as you guessed. My solution was to put a Solo Performance resonated X pipe (called Mach X) in where the factory downpipes resonators are, mutes the start to totally acceptable for me..and still have a nice bassy exhaust tone for driving around with valves open and gets rid of some of the raspiness of aftermarket exhaust, it allows sounds nice and quiet in comfort fwiw.

@cmoore86
The exhaust defaults to open with shut off, for cold start you get an initial startup bark with the valves open and as soon as vacuum builds they close no matter what mode you are in. I have a valve remote control from https://www.special-exhausts.de/shop/ that overrides factory setting and it allows you( if you want) to switch the valves to open right at start up and they will stay open.

[DeanoC]

I had to map out the cold start split injection and retarded timing.

As has been said above the valves will be shut when you start it in any mode after the initial 'bark' until you cycle the modes.

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[djnuge]

Great info.

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[Murazor]

You can turn off valve control manually, all you need is to disconnect one connector in the trunk.

[djnuge]

@Ducman5
I too had your problem, with way to crazy coldstarts, the valve remote control box won't help this as you guessed. My solution was to put a Solo Performance resonated X pipe (called Mach X) in where the factory downpipes resonators are, mutes the start to totally acceptable for me..and still have a nice bassy exhaust tone for driving around with valves open and gets rid of some of the raspiness of aftermarket exhaust, it allows sounds nice and quiet in comfort fwiw.

@cmoore86
The exhaust defaults to open with shut off, for cold start you get an initial startup bark with the valves open and as soon as vacuum builds they close no matter what mode you are in. I have a valve remote control from https://www.special-exhausts.de/shop/ that overrides factory setting and it allows you( if you want) to switch the valves to open right at start up and they will stay open.

Is this product available in the USA?

[Durin]

@cmoore86
The exhaust defaults to open with shut off, for cold start you get an initial startup bark with the valves open and as soon as vacuum builds they close no matter what mode you are in. I have a valve remote control from https://www.special-exhausts.de/shop/ that overrides factory setting and it allows you( if you want) to switch the valves to open right at start up and they will stay open.

Hi Spa, does that controller fully manually control the valves ? i.e if you want the valves closed in dynamic will it also do that ? When I installed my exhaust I had a simple switch installed into the factory wiring running to the vacuum solenoid in the boot, this allows me to open the valves even if I’m in comfort mode however it doesn’t stop the valves from opening in dynamic.

[spa]

Hi Spa, does that controller fully manually control the valves ? i.e if you want the valves closed in dynamic will it also do that ? When I installed my exhaust I had a simple switch installed into the factory wiring running to the vacuum solenoid in the boot, this allows me to open the valves even if I’m in comfort mode however it doesn’t stop the valves from opening in dynamic.

It will over ride the valve staying open in dynamic but when you hit the rpm where the valves open in any setting they will still open. But for example if you are cruising around in low rpms with valves open because dynamic and you hit the button the valves will close.

Is this product available in the USA?

They shipped to me (Canada) so I assume to the US shouldn't be an issue.

[djnuge]

It will over ride the valve staying open in dynamic but when you hit the rpm where the valves open in any setting they will still open. But for example if you are cruising around in low rpms with valves open because dynamic and you hit the button the valves will close.



They shipped to me (Canada) so I assume to the US shouldn't be an issue.

What is the correct model # for the one you installed? How is it working?

[Overbias]

Not sure if its already been explained but the loud cold start is only partly due to the exhaust valve position. The main difference in the sound upon cold start (vs warm start) is the Secondary Air Injection system (referred to above as split intake) this is the system that accelerates the heating of the Cats and recirculates the unburnt fuel in the exhaust mixture to re-burn it to reduce emissions during cold start. This is why the sound changes after about 30 seconds. The SAI closes and changes the intake path along with the valves closing to return to 'normal' exhaust pathway vs hotter, higher flow for when the SAI is open and the Cats are warming. Personally I wish we could rip it all out and just enjoy the NA sound all the time but then you know "The Planet" and everything. Conclusion, wresting manual control of the Exhaust valves will only partly change the startup sound.

[djnuge]

Not sure if its already been explained but the loud cold start is only partly due to the exhaust valve position. The main difference in the sound upon cold start (vs warm start) is the Secondary Air Injection system (referred to above as split intake) this is the system that accelerates the heating of the Cats and recirculates the unburnt fuel in the exhaust mixture to re-burn it to reduce emissions during cold start. This is why the sound changes after about 30 seconds. The SAI closes and changes the intake path along with the valves closing to return to 'normal' exhaust pathway vs hotter, higher flow for when the SAI is open and the Cats are warming. Personally I wish we could rip it all out and just enjoy the NA sound all the time but then you know "The Planet" and everything. Conclusion, wresting manual control of the Exhaust valves will only partly change the startup sound.

That's a great explanation. Now things seem much more clear. I removed my resonator so that initial cold start is "scary". Especially if you're starting your car at 2:00am in a quiet neighborhood. It's also bad when your parked somewhere and there are people sitting near the back of you car. You have to actually give them the heads up, unless you're in the mood to get yelled at by pissed off people. LOL.

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[spa]

What is the correct model # for the one you installed? How is it working?

I use it every day since I bought it, performs flawlessly. I have version 3. Send him any questions if you have any concerns. He was super nice and easy to deal with. Plus I got some free Haribos and a pen with the order lol.

[AGA_RS5]

My rs5 is straight piped. Plus I leave for work at 4:30 every morning lol. If you think you neighbors hate you then you should meet mine lol

[makisupa]

My rs5 is straight piped. Plus I leave for work at 4:30 every morning lol. If you think you neighbors hate you then you should meet mine lol

I’m also straight piped. Need to start it in the garage with the doors closed in the morning (leave before 6am) so my neighbors don’t completely freak out.


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[Ape Factory]

The SAI is only partly responsible...it doesn't circulate fuel but does inject more air as the injectors are being fired out of phase along with changes to the ignition timing to raise EGT's quickly and heat up the cats. The SAI's do exactly what their name says, inject more air into the exhaust which is needed to burn the additional fuel making it past the exhaust valves unburned. Remove the cats and no need for the SAI and no cold start. It's kind of like burbles.

[JamesRS5]

Replacing the air driven valves with electric actuators would be simple enough to do and clear out space to install a spare wheel if you wanted it.

https://www.aliexpress.com/item/32835851208.html

[[email protected]]

This module can keep the valves fully closed or fully open at startup:

Controller Package | RS5 Exhaust Valve <-Click Link for More Information

- Complete Control of Exhaust Valves with Factory Controls
- No Additional Key Fobs Required for Full Control
- Plug In - Tapping of Two Wires is Required
- Dynamic - Valves are Fully Open at All RPM
- Automatic - Standard Factory Valve Behavior
- Comfort - Valves Remain Closed until 5000rpm
- ESP Double Tap - Immediate Closing or Opening of Valves
- Startup - Valves Revert to Last Setting Used on Shutdown

This way you can use the factory drive select modes and make the valves behave pretty simple and more intuitively. No need for a key fob, changing how the valves are actuated, etc.

Cheers,

[JamesRS5]

Alex, how does installing a module maintain vacuum in the reservoir to keep the valves closed when the car hasn't been driven? That's just a control box but doesn't bypass how the system operates the valves, the only way to do this would be to remove the vacuum operated valves and replace with electrically operated actuators.

[Overbias]

This unit appears to be the best functioning of all of the ones I have seen. I don’t see installation details on the website. Looking at the wiring loom though it would appear that the current wiring is completely replaced. Can you confirm that and publish the install?


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[JaySline]

That's a great explanation. Now things seem much more clear. I removed my resonator so that initial cold start is "scary". Especially if you're starting your car at 2:00am in a quiet neighborhood. It's also bad when your parked somewhere and there are people sitting near the back of you car. You have to actually give them the heads up, unless you're in the mood to get yelled at by pissed off people. LOL.

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I installed a remus muffler today that went from the cylindrical resonators to the rear muffler. When I started up the car it was way too loud. So I took off the mid section piping of the remus and installed the Capristo front/middle muffler. Now the car sounds perfect. I can't imagine running this exhaust without the cylindrical resonators.