I'm not sure what they're technically called, but does anyone have an exhaust valve installed? It's a valve that opens up fairly early in the exhaust stream, and just dumps the exhaust before the mufflers or anything else in the way.

I know the rotaries benefit from free flowing exhaust, and I'm in the process of switching my 6th ports over to electronic actuation (so backpressure won't be a concern). I'm thinking of dumping exhaust just behind the presilencer.

How much of a difference would this make? It would obviously be terribly loud, but would the power gains in the high end be worth it?

-=Russ=-

 

It's mechanical:
http://www.jcwhitney.com/webapp/wcs/...gId=-1&TID=100

 

they used to call them crop dusters, cuz on old carbed muscle cars youd leave a trail of flames under your car.

 

That's what I'm looking for. What kind of power/efficiency gains do they produce on a rotary (probably similar to just open headers instead of a full exhaust system)?

I'd probably also dig up an electric version - I've seen them, somewhere. Just one more switch in the ever growing control panel.

-=Russ=-

 

i saw a video of same civic hatchback with like 500+ HP, and he smoked the **** out of a viper ... he had that on there ... it was activated by a switch, and just dumped the exahaust RIGHT after the exhaust manifold i think ... sprayed to the side of the car if i remember correctly ... anyone else seen that video?

 

scoot used something like this on there 4 rotor Fd,.. it opend up another, larger diameter muffler so that the pp motor could be properly muffled and still make power.

 

Most of them can't handle the heat of the 13B. Several people have tried, but no one has had success.

 

i cant imagine that cast iron moving parts would react well to rotary exhaust.

 

Ive got a cuttout that dumps just before the cat. sealed closed by a metal plate held onto the outlet with three studs and wing nuts. I got 2 at jegs for $60. Ive got a high flow system alread with the magnaflow high flow 3" cat and muffler that it really doesnt make that big of difference. I think i got an extr tenth in the quarter with it open. Very stinky. Cool to hear the turbo though.

 

A better option is to use v-band clamps in the construction of the exhaust system, and that way you can reconfigure the exhaust however you like within a matter of minutes. The cut-out system you describe shoots the exhaust out at an angle, which is not optimal. Also, you would need a resonator on the end to be legal even at the race track, and don't even think about using open exhaust on the street unless you want every cop within 20 miles homing in on you to give you a ticket.

Benny's exhaust system is a good example of the v-band modular construction concept. Also notice the slip-joints and tie bars that join the header to the Y-collector.
http://images.realride.com/cgi-bin/i..._Benny/exhaust

 

that isnt true i have videos of a 1/8th mile race track i went to in lakeland, huge rotary turn outs. some of with that on it sticking out the side right behind the front right tire then the other peice going back to a muffler for city driving. mostly saw it on first gens. the 2nd gens i saw their had a huge 4" downpipe.

 

unless you use it regularly i would bet the turbulence in the exhaust it would cause would be more of a loss than a gain. you would lose a little bit of power by just having it on there when not in use.

 

If you used a regular mechanical one (with wingnuts that holds the plate on) it'd work fine. It's standard grade mild steel, same as the rest of the exhaust. I could see electrical or cheap actuated mechanical ones having problems.

You can get them from SummitRacing or Jegs for something like 15-20 bucks.

 

There is a thread By Marcell burkett on the rotary performance section regarding one made by ATP which will wor, but is imited to 3". Carl

 

that might have been a pipe from the Wastegate.

 

MOST of them can't handle the heat. Didn't say all. The ones I am aware of have cracked/broken after a few hundred miles on the street.