EPA exhaust noise notice - good muffler?

[JETGSR]

I'm screwed?? i'd be lucky to be as low as 100Db and I have cat, and biggest muffler i can fit under the rear and a dumpy.

so far police have left me alone, but i tend not to be a smartarse and i'm an old bloke too.

bit it is something I will need to look at soon.

what about those mufflers with the internal spring loaded baffle that opens up underload.
never used one but have seen them. and from out side you would have no idea.

the baffle would stay almost closed under 4000rpm free rev but open up once under load.

most people dont make boost on a free rev ie: no load
load that engine up at same rpm and varoom BOOST and shit load more gas flow.

worth a thought?

 

[clone]

And what I they seize in some way ? Guess its the same as the varex

 

[EVOCPE]

You can get a control kit for the Varex now, which allowsyou to program the butterfly to open at certain RPM

http://www.xforce.com.au/about-varex-remote-control-sports-muffler.php

I was gonna ask them if any chance it can be made to open with pressure, that way just set what PSI u want it to open at

 

[khubner1]

are you talking boost pressure because surely with a electronic gauge/sender you could do what you planning. all it does is take a pulse from the cas/distributor. and a electronic guage works on a pulse. i think i might have a spare boost presure sender here might try hooking up to a tacho and see what it does. if it make the needle move it would just be a mater of finding out the range it makes the tacho move and programing the varex control unit accordingly

 

[EVOCPE]

Its the

VK05 (Trial Version)
Automatic control kit which features an extra function that can adjust the volume automatically according to the pre-set RPM by users

... and yes im talkin about boost pressure

 

[clone]

The new FP falcon v8 supercharged has this but it works on pedal position ie of the throttle plate. More then 40% open allows the straight through full flow exhaust

 

[EVO-00X]

Hmmm... that sounds like it could be better than RPM. How about reading from the TPS that indicates how much open the throtle body butterfly is! 40% sounds like a good start point to open up the varex. The stationary noise test governs what rpm to conduct the test 4000-4500rpm which if you programmed the varex to open under this rpm level you will get full flow and full noise risking failing the test. But if programned by TPS throttle position then you can do high rpm with minimal throttle... just gradually work your way up in pedal pressure and pass the test. Its also good to stop the back pressure popping sound when off throttle coming down from high rpm when the pedal is released. The pop is what usually fails you even if your exhaust is quiet.

 

[clone]

yeah ford actually made something good for a change. Only reason i know abit about it as i had to work on a couple that had a problem

 

[EVO-00X]

The HSV W427 introduced the variable exhaust valve into the Aussie manufacture market back in 2009. It was rpm based from memory. Took Ford a few years to make something similar lol. This goes to show that the laws are difficult to adhere to even in brand new V8 cars. The exhaust noise limit has made the manufacturers adopt this method to enter the market. Of course they wont market the variable valves as a must to meet noise control, they market it as a "quiet vs sports" mode novelty lol.
These cars already fitted with control valves from factory are legal.. but if fitted to a normal car it is illegal. Fukn double standards if you ask me.

 

[khubner1]

I agree if a butterfly valve is legal for production car should be legal to fit aftermarket. But it just like bike and fezzas they don't adhere to the 90 db either bikes I know have their own rule but super cars don't follow the rule. Seems its a case if pay enough money and well pass anything

 

[ONPSI]

For the boys in QLD I'm about to go get tested as I got done last week. Lucky I was only 107db! I was sure I'd be heaps higher then that. They make you rev to about 4700rpm. I didn't close my varex either as it hasn't been working for a while. Got some tricks to get it under the 90db, will update once I clear it

 

[khubner1]

unlucky man. good thing is tho we don't have im240 emissions tests here. (yet)

 

[EVO-00X]

Here in NSW if you get referred to a DECC checking facility, the guy actually has your car up on a hoist and inspects the exhaust system for baffles or obstructions. He looks at the cat too for obstruction or if its been gutted out. If it doesnt have any markings on the cat that prove adr youre fukd, if the cat is welded in youre fukd because he cant remove it for inspection either. Just be careful where tou get referred to because they fine you for doing stuff like that.

 

[ONPSI]

Don't say that...although my exhaust itself is legal meaning I have a proper cat, but it ain't goin on a hoist...

 

[EVOCPE]

I know a good way to get your exhaust quiet

Cut a 2mm plate in the shape of your flange half way down your exhaust, drill some holes in it, on the engine side throw some exhaust silencing material/steel wool or whatever

 

[4piknup]

I used to push steel wool up the pipe.

As I have a ebc, and starting to up the boost, I was going to use the standard boost ecu trigger to run a relay and trigger a Varex into the sport mode.

 

[BZY247]

Those interested in different Varex mufflers.
I have had the cannon, twin tim and now a single tip oval.

Cannon is the loudest for obvious reasons as the body is pretty small hence lack of noise resonance.

Twin tip is also a straight through design, in fact the twin tip oval and single tip oval is exactly the same, but are less noisy than cannon as there is more body to help reduce the sound.

Twin tip exits into one tip which then instantly splits into the twin tips.

What i did now is got my single tip oval varex, cut off the single tip with "Varex" writing on it and welded on a 4" dump tip.... Looks just like an old skool oval muffler now with a dump tip. It could just be in my head but due to noise/exhaust getting thrown downwards i can swear its not as loud.... while maintaining the 3" straight through piping design.

I have not closed the butterfly on this muffler yet as my cig lighter is fruked, so will be hard wiring it shortly, which is also more stealthy.
FYI when having the dump tip welded on it allows you to really fit the muffler as hight as possible tucked in under the body, which also hides the varex butterly motor unless you lay on your back, get under the car and tilt your head up to try catch the glimpse.

Hope this helps.

 

[BZY247]

 

[evo-gsr]

The noise of a 93t is no comparison to a 63t....different kettle of fish.

 

[ONPSI]

So my varex works now, I'll get a db meter on it in the next few days and see how loud it is with it shut vs. open (107db @ 4500rpm)