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Installing aftermarket exhaust with vacuum-valves. How to wire it up?

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I recently bought the DesignTek Valvetronic exhaust system from Design 911. Unfortunately no installation-instructions were included. I've emailed Design 911 about it, but after 1,5 weeks they haven't made any progress. The only email-address I could find for DesignTek was parts@designtek.eu, but emails bounce. Then again, how hard can it be? :P

I've installed the mufflers. They sound great but the default mode is LOUD which isn't always so popular amongst the neighbors. Each muffler has a single vacuum-valve that closes the flap with vacuum present. The kit also included a vacuum reservoir, an electronic valve, a one-way-valve, a box for the idiotic remote control, keyfobs, a length of hose and various fittings, strips and cables. I have the Porsche factory PSE-switch for use with this and hooking up the electronics is easy. The vacuum though, not so much. I found a place to tap into the vacuum-system, on a valve on the back of the intake, left side. Not sure which side of the valve I should hook into though. Then there are the tank, one-way valve and electronic valve. I've tried to apply logic and came up with the following:

Vacuum from car



One way valve to prevent the vacuum tank and mufflers to feed vacuum back to the car in low-vacuum situations.



Electronic Valve



Two t-junctions to feed three hoses

// // \\

// // \\

Mufflers Tank Electronic valve

The valve either allows vacuum to pass through (power applied) or dumps one side of the valve to free air (power not applied). So with power on it allows the car to pull on the valves on the mufflers, and with power off it releases the pressure and the springs in the valve pulls it open. Sound good or did I miss something? I'm at vacuum 101 here..

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  • 3 years later...
  • 4 weeks later...

there's really nothing complicated about the Design-Tek system - all you need is a switched 12V to the air valve solenoid. The system is supplied with a good length of silicone vacuum pipe that resists heat form the exhaust and engine bay.


I wanted to use the OEM Porsche exhaust switch so fitted a 'ratchet relay' so that sucsessive pushes of the porche switch causes the valves to open or close. An additional wire back to the switch from the relay brings the LED 'active' light on when the button is pressed and the valve is open. My car is a convertible and I mounted the relay next to the engine ECU. The solenoid is mounted in the engine compartment, I took a vacuum feed from close to the inlet manifold and the system has always worked fine.


The only 'problem' that I have experienced is that if the car has not been used a a few days then the exhaust is at 'full volume' for a few seconds after start whilst the vaccum system builds enough negative pressure to operative the valves.


I didn't use the remote control system that was supplied with the system - I really didn't want the control the valve with a key-fob and to be honest I don't see why they supply this as part of the kit.     


The Design-Tek system is a really good quality unit at a low cost. I would recommend it to anyone.

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hehe, way to revive an old thread. 


I got it installed, wasn't too hard. And hooked up to an original Porsche exhaust switch (with a clear coating to match the other switches). That car is sold now, the Turbo I have now has a Milltek exhaust, no switch :)

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  • 7 months later...


I just ordered the valvetronic mufflers from Designtek to my 997.2 4S. What´s your experience about the sound level with closed valves compared to stock? With open valves, is it noisier than PSE or similar?


How and from where did you feed the 12V for the control valve?

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