Muffler Testing, etc.
Caveman, yessir, that is my 340 with one of the GTO sets on it for sound testing. The real ones are even better but I could not get the microphones in the right spot when I made that video.
I worked very closely with Joe at Waldron on this project. The cool thing is the ones he can make for A-bodies can be right at the 18" and 4.25" by 10.25" shell. He can go 2.25" or 2.5" like I did my prototype set.
TS, they use a large plate/valve that covers a bypass internally and when closed by spring pressure, they are like the stock 340 three pass muffler but when open using the vacuum actuator, the exhaust bypasses two of the tubes and exits through openings in the outlet bushing.
The vacuum signal is acquired from the back of the intake and then feeds a canister hidden under the driver's side front fender. The cannister connects to the switch which I have in my ashtray replacing the nitrous switch (from 1979) and then it connects to a nylon tube going back to the mufflers. Any vacuum signal from around nine inches of mercury and higher will actuate these.
We are both seeing about 7 to 10 dBA difference across the board (between open and closed) pretty much independently of the engine size except for the lower compression or smaller HP engines.
Caveman, yessir, that is my 340 with one of the GTO sets on it for sound testing. The real ones are even better but I could not get the microphones in the right spot when I made that video.
I worked very closely with Joe at Waldron on this project. The cool thing is the ones he can make for A-bodies can be right at the 18" and 4.25" by 10.25" shell. He can go 2.25" or 2.5" like I did my prototype set.
TS, they use a large plate/valve that covers a bypass internally and when closed by spring pressure, they are like the stock 340 three pass muffler but when open using the vacuum actuator, the exhaust bypasses two of the tubes and exits through openings in the outlet bushing.
The vacuum signal is acquired from the back of the intake and then feeds a canister hidden under the driver's side front fender. The cannister connects to the switch which I have in my ashtray replacing the nitrous switch (from 1979) and then it connects to a nylon tube going back to the mufflers. Any vacuum signal from around nine inches of mercury and higher will actuate these.
We are both seeing about 7 to 10 dBA difference across the board (between open and closed) pretty much independently of the engine size except for the lower compression or smaller HP engines.