I know it's not an internal engine mod, but didn't know where else to post the ? I have a bi mode exhaust on my vette. Stock from GM. In the quiet mode, it routes the exhaust through the muffler and is "stock" quiet. In the straight thru mode, the exhaust goes straight thru the muffler without any muffling. It's like a straight pipe instead of a muffler. You control it with vacuum. With no vacuum, the flap that diverts the exhaust through the muffler is open....hence, at WOT, it's like a straight pipe. Bullet loud. With the flats are closed, it's as quiet as a stock muff.

I wished someone would make the system for our trucks. The vette mufflers just won't fit. To me, that's the ideal exhaust system. Loud when you want it, and quiet when you really get tired of the noise. I've searched and apparently they're only available on vettes. Anybody heard any different?

 

electric cutout

 

It's quite a bit quieter than cutouts. With headers and no cats, cutouts would attract more attention than I'd want. The bi mode muffs are loud, but not so loud as to get you a ticket. I have cutouts on my truck and I wouldn't think of opening them up around town. The bi modes from GM, while loud, won't get you thrown in jail toolng around town.

 

there is a guy on here(cant remember his name), but he has his cutout open to another muffler rather than just open exhaust like ur looking to do...

 

i think thunder550 has or had a vacuum activated cutout on his truck, i am not positive but you may try sending him a pm

 

I have cutouts now. They're way too loud to drive on the street. I'd like to have a bi mode muffler like the vette boys have. The muffs on my vette have a switch that makes them adjustable between agressive and stock sounding at the press of a button. Best of both worlds. B&B Fusion is an aftermarket version for vettes only. A little louder than the vette GM "NPP" mufflers. Also, the Z06 vettes have a similar setup. I can't believe no one makes a similar muffler for other applications. How many times have you wished your big mouthed exhaust would shut up and behave?

 

yes i read that but you could use one of those cutouts through a bullet muffler or maybe one of the flowtech (i think that is the brand) mufflers that has a straight through side with a cutout type opening. it would normally go through the muffler side and when you got into it the cutout would open and you would have sort of a bi-mode exhaust system.

 

BTW, the section you should have put it in was "GM Engine & Exhaust Performance".


Not being rude or anything. Just FYI so you know.


I really need a cut out. I passed a bunch of harley's today and felt bad because they were louder

 

Isn't that what Corsa is known for? Quiet when cruising with no drone then when you hammer down on it very loud? Why not take the smallest straight through mufflers on put them on your cutout, hell even a glasspack? Then it would be quieter than when just open pipe? Get some purple hornies or whatever with the 3 bolt flange and bolt it up. They have a turn down on the end so you would have straight through performance that made it a little more quiet

 

There is a company that makes a bi mode exhaust muffler. Look for waldrons. They make a reproduction of the 1970 GTO stock bi mode muffler. BTW, I used a 2006 Z06 muffler under my avalanche, it is still pretty quiet.