I was wondering if an exhaust brake or something of the sort would be an effective boost decreaser? I know that a boost controller hooked to the wastegate can only increase boost. But what about decreasing boost?

Also it would be an effective silencer for city use. And increase spool up time. Would it not?

I've seen for hotrods a selector Y-pipe that has a flapper that shuts off one or the other outlets. Like for straight pipes as apposed to mufflered.

It got me thinking if this would be an effective "VARIABLE restrictor plate"?

 

i always thought it would be fun to have a valve that switched from a nice, conservative street exhaust to straight pipes w/o emissions

nice surprise for whoever decides to race you

 

Someone had a valve that he rigged up where it used the whole exhaust system with the valve closed, and when open it just vented straight out.

 

APEX'i has something like that, they use a stepper motor to switch between silent mode and power mode.

 

They sell them through Summit Racing. An electironic exhaust cutout that let you switch from full exhaust to open downpipe with the flip of a switch.

 

Exhaust cutout, thats the word I was looking for. The one this guy had was similar to the summit one. He was selling it last month.

 

https://www.rx7club.com/west-rx-7-forum-193/fully-automated-exhaust-silencer-581180/

 

I decided to just put a manual exhaust cutout(The one that requires you to climb under the car and take off the cap) on my TII GSL-SE because the electric ones are expensive and I only plan on opening it up at the track. I live in a small town with one main road and an open downpipe TII would probably draw every Cop in 2 miles, lol.

 

ATI, IIRC, makes one taht essentially uses a wastegate actuator to open the cutout under boost. You can set it to open at any pressure, and when your intake reaches that pressure it opens turning your exhaust into an open downpipe.


BC