matt33

Has anyone tried the below combo and/or able to guesstimate on the decibels:

Turn away pipes
Sharkwerks center
Stock side mufflers
GPS valve closer

I moved from stock sides + BBI center (sounded incredible) to side delete with stock center and hoping to find a middle ground that will still pass sound.

Thanks
Matty

adi_d

Matty,

Stock sides + sharkwerks center + side pipes + gps will definitely pass sound. I ran the setup for a year. I think with walves open it is about 100db and closed it is obviously around 90db.

Sound was definitely better/more noticeable than side delete and stock muffler, but then you add the 40lbs weight back

matt33

Thanks Adi.. I will probably go to that setup. Unfortunately the BBI center has integrated tail pipes so cant add the turn away pipes so probably going to go with the SW.

Matty

bweSteve

Hey Matty,... Just a thought,.... (& I'm not in Cali, so do not have this issue here in MD. In fact just passed Emissions w/ stock sides & Sharkwerks Center)....

But to pass sound in Cali,... with a stock side + center bypass,... you could simply disconnect the vacuum solonoid in the engine bay (eliminating any vacuum entering the lines just to be safe), and then on the DAY that you are going in for testing, simply clamp the valves closed on each side down at the valve. Then unclamp it when you get home.

Not sure what your ultimate goal is here (whether a particular exhaust setup,... or maybe to get as loud as possible but still passing sound tests,.... etc etc)

=Steve

matt33

Thanks for your thoughts Steve. My goal is the best possible sound (not necessarily loudest).. while still able to pass sound.

I currently have: valved side deletes + GPS closer + stock center + turn away pipes.
Definitely passes sound and sounds "good"... just a long way short of the absolutely incredible sound with stock side mufflers + BBI center section (which unfortunately ran at 103db!).

Per Adi's experience.. my new thinking is: stock side mufflers + SW/similar center + turn away pipes + GPS. The advantage is a (hopefully) much better sound, the disadvantage is adding weight and heat to the back of the car with the stock side mufflers. SW/similar is required over the BBI center as the BBI has integrated tail pipes so cannot attach the turn away pipes.

Matty

bweSteve

correct me if I'm wrong, but when the valves (just prior to the center bypass) are left open, the majority of the muffled interior of the side mufflers are bypassed.

This pic is just before I installed the Sharkwerks center bypass...
When the valves are open, I thought it was a quick straight pass-thru along the bottom of the side mufflers. But I've never seen a cut-away of the side mufflers, so I don't know that for a fact.
Looking at a pic, my impression was that it flows from the Cat, straight thru the bottom of the side muffler, and into the bottom outlet (then thru the open valve) & out the tip...

bovien

Sorry to hi-jack a bit, but which GPS Valve option are you using?
The build-your-own, or is there a viable option to purchase?

matt33

I use the Alekshop GPS product

bovien

Thanks! I will get one if possibe. Are you able to program GPS points where the valves close yourself? I'm in Denmark and driving small tracks here and sweden, and would need to program the device with GPS points. I cant find any info online on the device.

Spyerx

FWIW on my 3.6:
cup 100 cell headers
side bypass pipes
stock center
small holes capped

102db measured at thunder hill (entry to front straight full 3rd gear throttle)

LateBraking

Pretty much, yeah.

Side exhaust cutaway. Path shown is when lower valve is closed, so obviously when valve is open, path is more direct.



Center exhaust path valves open:



Valves closed.



Probably simpler in your case to get the Carnewal manual valve controller, this is what I did. The product works well if you want to manually control on/off for your side valves.

http://www.carnewal.com/products/997...Manual-Control

bweSteve

Thank you very much LateBraking for posting those pics. Exactly what I wanted to see.

bovien

Very interesting!