jadeboy

iTrader: (1)

I have researched options to control (turn on and off) the noise from my Borla Exhaust Catback, it seems the solution is to install a Butterfly valve exhaust control valve. Has anyone been able to implement this with success?

redcrxsi

Where would the exhaust value redirect the exhaust gas? You'd have to install something else to actually quite it down. The valve would just redirect the glas flow...to somewhere.

jadeboy

iTrader: (1)

I would likely have to change the muffler.. The X-Force Varex remote control muffler with the butterfly valve seem to be an solution... just don't know if it will fit with the existing Borla Exhaust Catback.

redcrxsi

Ah, that makes much more sense!

Borola runs 2.5in pipe and considering the various options available with that exhaust I'm sure you could fine one that would fit.

id suspect you would need a muffler shop to install to deal with the hangers etc but should work. No idea if it will sound good or last reliably.

Also not sure on the exhaust tips but something could be divised to work with the stock tips.

mcauley

iTrader: (2)

I have though about this. I too have the borla exhaust and if i block the two lower exhaust outlets it does away with the noise completely. I used a wet cloth to block them. i though about getting a shop to weld on a valve just as it leaves the boxes.

flowrider

iTrader: (9)

PPE has a solution with their Dual Mode Exhaust:

http://www.ppeengineering-onlinestor...ust-950010.htm

Lou

BLKLBL

blocking the lowers quiets it down.. Did you try to block the uppers instead of the lowers? Looks like more clearance with the uppers to install valves...
I measured the outlets, they look around 2 inches.. Amazon.com sells cheap butterfly valves in 2 inch that may work to block either the uppers or lowers if welded on...

jadeboy

iTrader: (1)

Please provide full details of what you used, the results and cost.. I would prefer to keep the borla muffler..

jadeboy

iTrader: (1)

I just placed wet cloths in the bottom outlets.. drastic different in noise. the droning is almost completely gone.. there is still some noise in the middle and higher frequencies. but the annoying low frequency is mostly gone..

I don't want to permanently close the bottom outlets. So a cap (similar to rain cap for exhaust) or butterfly valve exhaust is a solution.. the only challenge is that almost all butterfly valves are made for exhaust flange and not muffler outlets.

jadeboy

iTrader: (1)

It's finally installed..

I tried welding the butterfly valves (didn't work really well).. but the better solution was to used exhaust clamps with pipe size changer (2" on borla muffler outlets, 2.5" on the butterfly valves).
The Borla muffler bottom outlets were cut to be straight to fit the butterfly valves. The most time consuming task was cutting the exhaust tips to fit the butterfly valves.

Decibel reading went from 76 dB to 66 dB on idle, from about six feets behind the car on the ground. Most of the "lower" frequencies were mostly eliminated - it's most annoying noise on longer trip.
Really happy with the end results but it was a pain to get working.. if I had to do it again, it would probably take 8-10 hours, I probably spent 24 hours in total on this installation.

FFM

Nice work, I'm always curious as to what configuration of plumbing goes on inside these mufflers. The ideal design, and likely what PPE does, is that one path is perforated (the quiet side) and then the other is a straight pipe (valved).

If Greddy made a stainless version of their exhaust, since they utilize a twin entry design to the muffler, you could valve one of them and in theory, when closed, that chamber would act as a helmholtz resonator. Man I wish my fabricator buddy still lived in town. I'd like to design my own ultimate system.

Vervish

iTrader: (4)

Nice work - where did you get power to control the valves? Did you run a new power line from battery or did you pull power from trunk?

jadeboy

iTrader: (1)

I connected the remote cable (one of the ML AMP) from my JL AMP to a relay for trigger on and the main power came from the battery which was wired to the JL AMP.. very simple setup.

mahcah

iTrader: (3)

I have to say this is a great alternative to the PPE dual mode exhaust system. I will be divvying up something similar to this.

tas02

iTrader: (2)

That's a cost effective solution, sir. Nicely done.

FFM: Though Helmholz resonators look like "bullet" mufflers on the outside, an open chamber on the inside is required to achieve the intended result.