Exhaust Control Valves... Worth the effort?

**RAd28** · 19-07-2009, 09:26 AM

Hi guys,

I've been giving some thought to toning my exhaust down a few notches. At the moment I love the way it sounds, but it's a little harsh on the ears at night time when I just want to sneak home with the better half sleeping in the passengers seat. I thought about one of those stupid exhaust volume mufflers, but then I thought one of those butter fly valves with some holes drilled in it might do the trick... but the only ones I can find are Apexi brand, selling for ~$300ish which is out of the question.

So.. 2 questions are; Does it make an appreciable difference to the noise level? Can I get one cheaper then $300?

**Cuts** · 19-07-2009, 09:30 AM

would make a difference but IMO its not the right way of lowering noise level.

chuck in an extra muffler or resonator insted, save yourself a couple of hundred bux and sleep easy in the knowledge that you zaust is nice and free flowing.

ohh and the holes drilled in it idea will just increase the volume again.

**jeffro ra28** · 19-07-2009, 10:43 AM

I put one of those butterflies things on an rb20, didnt do a thing really.

Perhaps it has more to do with the location at which it is fitted ?

**Moppitt** · 19-07-2009, 11:22 AM

Theres a bit of info in this thread

http://www.toymods.net//forums/showt...+control+valve

I looks like an interesting way to have both a free flowing (yes, loud) exhaust when you want it and a quiet thing to sneak home when you want it.

Its done by a lot of manufacturers these days too. I've seen BMW's with a similar thing (although vacuum controlled shutting off one of the twin exhaust tips), have also heard about then new aston martins having something similar.

**TERRA Operative** · 19-07-2009, 11:39 AM

What about a Varex muffler? According to Xforce, they flow equal to a straight through muffler when they're in 'open' mode.
(Although they told me that they had lost the flow charts when I asked them for specs??.......)

**ReQuieM** · 19-07-2009, 12:29 PM

I didn't notice enough of a difference to justify the loss of flow/power so I ditched it and built a new quieter exhaust instead. You can get them from autobahn for about 150, that was about 1.5 years ago tho.