I tackled this in a different way, I did not want to have a remote in the cabin or give up two of my homelink buttons for flap on and flap off.
I found a switch at radio shack that looked close to OEM and fit into the hole in the ashtray where the cigarette lighter goes. I used the lighter ground connected to one end of the switch and ran a wire from the other leg of the switch under the counsol, into the Battery compartment and into the trunk. I then used a standard auto relay ($5 with wiring) I then bought a "extra circuit" from AutoZone that plugs into where the fuse normally goes, this device add a power circuit that I used to power the relay, ground for the relay was from the ashtray switch and the "switchable" power from the relay, i ran a short wire with a spade end and inserted into the circuit extender where the fuse normally would go. This when powered provides power to the one side of the fuse that goes to the exhaust flap vacuum pump. I was simple, cheap ($15 max) and works great. Easy to use and right at your finger tips

 

keitheva,

Just wanted to say thanks again for your post. I just installed the "Mild to Wild" unit according to your instructions and it works great! It was also really simple to do. I now have my normal sports car mode and a stealth mode for when I want to quiet things down. I had already forgotten how quiet the car is inside the cabin with the flaps closed -- it's like driving a BMW except for the grumble on the overrun and when the revs are over 4500.

Best,

Dave

 

Thanks and you're welcome Dave, glad it worked out!

 

I've been experimenting with the remote switch and I've noticed that the flaps tend to open up on their own after I manually close them. As far as I can tell, the flaps tend to reopen when I am no longer on the gas (e.g., at stop lights, when slowing down on the highway, etc.).

Could it be that exhaust pressure is required to keep the flaps closed? It seems like when the flaps are not disabled (OEM operation), they close only when you hit the gas. For example, when you are at idle or when you brake you can hear the throaty grumble, but as soon as you get back on the gas you can hear the flaps close up and the grumble goes away.

 

Yes the tube used to keep them closed is a vacuum tube and that requires air flow.

 

Actually, it's a common misconception that the flaps are closed until approx 4K RPM. What really happens is that the flaps are open at idle and closed from 1500 to about 4K, then open up again. This helps keep the engine from stalling at idle - the old "banana in the tailpipe trick".

 

I was under the impression that the flaps were open at idle to provide a more "robust" sound at idle and start-up.

 

Okay. Any idea then why this doesn't happen with fuse 15 inserted? I mean, if pressure is required to keep the flaps closed when I'm using this remote control unit, why isn't that same pressure needed to keep the flaps closed when fuse 15 is in place? The flaps didn't open on their own before I pulled fuse 15. There must be something additional going on here due to the presence of the remote control unit.

 

The flap is actuated with a vacuume pump that is electrically powered. The ECU tells the Vacuum pump when to provide vacuum to close the flap and quiet the car (generally 1500-4000) rpm. This is why when you pull the fuse the flap is allways open and the car is louder. The Prosche sports exhaust work the same way, so that the car will pass teh european drive by noise test.

 

Does this allow full control of the flaps, i.e. can you keep them closed at idle and high RPM? If so, could you provide more detail for us more short-circuited minds?
Mark

 

Just curious, but why would you ever want to keep the exhaust flaps closed at high revs?

 

The remote switch when turned off has the system on loud all the time reguardless of the rpm. However, when the switch provides power it operates as from the factory, I.E. Loud to 1500rpm, quiet from 1500-4000, and loud from 4,000 on. I can see why at times (late night near home) it would be nice to have it in the quiet mode but to do that you would have to provide power directly to the vacuum pump and by pass the ECU control. Not that hard, but... The Porsche sports exhaust was easy to set up that way as it used enging vacuum (vice a pump) that allway provides vacuum, and when the solnode had power it had the exhaust on quite. The factory set up does as the Aston, quiet from 1500-4000.

 

My car is much too loud to drive aggressively in the city

 

I've continued to play with the remote control and so far I can't identify any pattern to the car automatically returning to "always open" flaps other than the absence of throttle. Even then, the return to always open after removing throttle is intermittent.

Since the vacuum pump that controls the flaps is electronically operated, there must be something going on in the remote control unit that enables the car to return to always open flaps after I have put the car into OEM operation with the remote control. I wonder if it's a fault in my particular unit, or if it's just that the unit wasn't intended for the Aston application and, as a result, it can cause this to happen.

keitheva, have you noticed this issue? I'm debating purchasing a new remote control unit in case mine is defective, but I don't want to do that if it's just a consequence of the circuitry of the unit.

 

Am I to understand that you have a habit of driving in the city at 4000 to 7000 RPM but still want to remain "quiet"?