Dual exhaust for Bonneville wagon

[jmt455]

I worked with the new owner of my old company to develop a dual system for 305 G body applications.
Here is the system on my Bonneville wagon...

Here are some pictures of the system in my car...please excuse the dirty, greasy underbody. Cleaning up under here is on my winter project list!

This view makes it look like the pipes are not evenly spaced on each side of the driveshaft, but they are equidistant from the driveshaft centerline.

We added the offset (the small "S" bend) on the passenger side to follow the floor pan. All pipes are 2 1/4" aluminized steel:

Anybody recognize these mufflers?

Tailpipes exit just behind the rear wheels:

A few of my friends have heard the car and we all agree that this stock 305 has no business sounding this good!

 

[Bowiemontecarlo86]

Looks good bro you should make a video and let us hear it running.

 

[Longroof79]

Nice system, Joe.
Are those cut-outs in front of the mufflers? I like how clean the tips exit behind the rear wheels.

 

[Bonnewagon]

Very nice! That trans crossmember sure helps a lot.

 

[jmt455]

Looks good bro you should make a video and let us hear it running.

That's the plan!
If the weather holds (meaning no snow!), I'll be posting a video in the next couple of days.

 

[jmt455]

Nice system, Joe.
Are those cut-outs in front of the mufflers? I like how clean the tips exit behind the rear wheels.

No, they're not cut-outs...but they are closely related
Those are vacuum actuators that operate a bypass valve inside the muffler.

They are reproductions of the 1970- Pontiac GTO "Vacuum Operated Exhaust" (VOE) system.
There is a dash-mounted vacuum switch that allows you to open or close the bypass from the driver's seat.

Here's a video clip of the system on one of my previous cars:
http://www.youtube.com/watch?v=pSEvVso21pM&feature=g-upl&context=G2c9f82aAUAAAAAAAQAA
So much fun!

In "open" mode, they tested the same as Turbo mufflers (flow rate and dyno tested on the 71 GTO shown in the video)
In "quiet" mode, they flow and perform like the stock Pontiac passenger car muffler.

 

[magoo_oner]

How much does a exhoust like that run

 

[jmt455]

They are working on their kit pricing...should have numbers shortly.
I'll post an update when he's ready with prices.

The VOE mufflers are expensive - they are all stainless steel. Two mufflers with the control kit start at $570.

 

[pontiacgp]

Nice system, Joe.
Are those cut-outs in front of the mufflers? I like how clean the tips exit behind the rear wheels.

No, they're not cut-outs...but they are closely related
Those are vacuum actuators that operate a bypass valve inside the muffler.

They are reproductions of the 1970- Pontiac GTO "Vacuum Operated Exhaust" (VOE) system.
There is a dash-mounted vacuum switch that allows you to open or close the bypass from the driver's seat.

Here's a video clip of the system on one of my previous cars:
http://www.youtube.com/watch?v=pSEvVso21pM&feature=g-upl&context=G2c9f82aAUAAAAAAAQAA
So much fun!

In "open" mode, they tested the same as Turbo mufflers (flow rate and dyno tested on the 71 GTO shown in the video)
In "quiet" mode, they flow and perform like the stock Pontiac passenger car muffler.

so those Dynomax mufflers that have the "new" invention of a valve isn't new at all....

 

[jmt455]

The Dynomax design is different; it opens and closes without operator control.
The Dynomax valve is spring-loaded; it stays closed until the spring's resistance is overcome by the exhaust gas pressure acting on the valve. At sufficient flow rates/pressure, the valve opens.

It's amazing how many different systems have been patented over the decades.

Back in the early 1900s, muffler bypass valves were a popular accessory on many vehicles.
They were cable-operated bypass valves, mounted at the muffler inlet...a precursor to today's electric cut-outs.