Hey ppl saw this system on reviewed on autospeed 4 years ago, was a cool idea but operation was crude...
now it's been updated and looks awesome so check it out...
http://www.hyperflow.com.au/techaes.htm
http://www.hyperflow.com.au/techbulletins/Active_Exhaust_System.pdf
http://autospeed.drive.com.au/cms/A_2291/article.html

apart from making you exhaust quieter with much less drone the additional back pressure at low revs / part throttle will restore the bottom end torque you lost when you installed a straight through exhaust...

It would be nice to see it on more cars from the factory.

A few cars that I can think of that have a variable muffling system: Mitsubishi GTO, VW Golf R32, and for some reason some expensive car like a Ferrari is popping into my head.

What I want is a valve on an exhaust dump pipe that is near the engine. When you open it, it goes loud. Real loud. I've started my car with only the exhaust manifolds attached. I have a video of it but there's no revving because there were neighbors all around.

Operating in an envronment like an exhaust system I'd give it a few months life time, diaphragms and valves don't like those conditions, just ask 3.0l diesel patrol owners who are going back to nissan in under 15k because there engine either wont run or are gutless.

Operating in an envronment like an exhaust system I'd give it a few months life time, diaphragms and valves don't like those conditions, just ask 3.0l diesel patrol owners who are going back to nissan in under 15k because there engine either wont run or are gutless.

no probs with reliablilty (dont know what a diesel pajero & or patrol have to do with this system)

"the new valve’s bushes and shaft are made from the same sort of materials you’ll find in external wastegates – their high temperature resistance makes them ideal."...

"The operating environment is corrosive, hot and often extremely dirty. The HyperFlow Active Exhaust System is manufactured to exacting standards to assure reliable operation. In this current environment of noise regulations and ever more aggressive law enforcement, the HyperFlow AES is and ideal addition to high performance vehicles – you select, noise or no noise…"
The system has a 1 year warranty as well...

I have spoken to the guy that invented it and it is made out of I corrosion resistant alloys. Very cool, should last for ever.

Cheers
Mattg

I never said anything about corrosion, merely operating conditions. An exhaust is full of both particulates which seize moving parts quickly and temperature which ruins diaphragms. I mentioned the 3.0l patrol because they've included a diaphragm operated nozzle ring in the turbo, inside the turbine housing to adjust the turbos drive properties as the engine accelerates to increase it's power spread. This sounds like a good idea in theory, but in practice these fail regulalarly and are being replaced under warranty at alarming rates, nissan sends the cars to us to diagnose them so we see a few :/ Just saying I've seen to many good theorys put into practice and fail miserably because the engineers just don't/cant account for operating conditions.

Matthius

The diaphram is not in the exhaust flow but located on an arm to control the butterfly but I can see your point that it may get very hot. The butterfly looks very solid but you never can tell but since they offer you a warranty then I assume it would work pretty well. There was also a manual one by Apexi for around $250 I saw in another mag. Anyone know how much the active one is? Its distributed by MRT so I would guess big bucks.