Sweet!

What about when the pin that the plate is on gets rusted into place (doesn't take long with 409). I'd think it would be a big waste of $$$. That'* $140 ($70x2 if your doing duals) that could be put towards a CAI, high flow cat, full tune-up, etc...

I hope no-one waste'* their blingage on these.

I was just thinking about welding a 3" flapper tip to a flange that will bolt on to the downpipe flange from my headers so I can remove the entire exhaust for track use only. That would drop some weight and high rpm backpressure while still maintaining some low end torque.
May have to increase the backpressure spring slightly, and fab up a 316 ss pin to replace the stock 409 one but it just may work...........open headers.
It would be loud as hell, like when I drove to the muffler shop with open headers to get the exhaust flange welded on. The lack of low end torque was noticeable but when I put the hammer down....

Just an idea right now for a future project.
What do you guys think :?:

Yer crazy and I love it

Has it ever been done??

Innovation is the mother of invention.

it`* already out there ....called exhaust cutouts 2 1/4 or 2 1/2 diam. you slip it over your exhaust pipe weld it up just past your collector and has 3 nuts/wingnuts that holds a plate you take off so you can run it like a exhaust bypass ....works great .....but now the 1/4 tracks going to full exhaust ...open headers /shortie pipes are being outlawed for noise.... but its still a good idea if you what to make your own ........just cost wise...i found it cheaper to buy mine thru Summitt.......

I think he'* talking about a cutout that can create backpressure to a certain point until the spring resistance is overcome. It'* a new twist on an old idea.

Gonna have to be a light spring.

I don't like stainless steel springs, they break. The one in that unit is probably low alloy steel.
It would be even more challenging to install a rotary positioner that is electronically controlled to vary the backpressure flapper depending on engine rpm or simply have two positions, barely open for quieter low rpm and full open for the kill.

You could run it off a throttle cable.... Just hook up another to it or something, like dual carbs?
I meant a light spring, as in light action/resistance, to keep the flapper closed.