I remember seeing on the site sometime ago about a flaper valve that could be installed inline with any exhaust system. This flaper valve would remain partially closed at idle, and then when WOT it would gradually open. This in turn allows drivers with large diameter exhaust piping to have low end tq due to the back pressure that the flaper valve gives. Then at high RPMs the flaper valve opens up all the way to allow a free-er flowing exhaust.

If I remember correctly there were two types of flaper valves out there; mechanical and electrical. The mechanical is directly controlled by the driver by a lever from inside the cabin. The driver could then adjust the flow of exhaust and also change the tone of the exhaust for highway driving. The electical is directly controlled by the RPMs, the more RPMs the more the valve opens. Being able to adjust the valve's opening for tone control, that I don't know.

But I've tried searching the forum and the net and found nothing. Maybe I am not naming this device correctly. Anyone know of what I am talking about and where I could find something like this?









Juker008

 

I saw that on "Trucks" a while back.. the guy had that on a truck he was building. It basically worked like a exhaust bypass valve. On regular driving conditions, he has his exhaust system flowing through the cat and muffler, but when he wants to get a little more kick, he flips a switch and the exhaust becomes free flowing straight out of the exhaust manafold, for that few extra ponnies.. I thought it was pretty cool!

 

http://www.buickgn.com/electricexhaustcutout.htm



Your welcome.....:P



Smitty

 

Smitty U ARE THE FKin $HIT !!!
TNX A FK BUNCH !!!









Juker008

 

Looks like I'll be getting a new Mod soon. FUck the B-pipe, that shit is wack.

 

someone find out if this dude will do a groupbuy.

 

I heard from a buddy who has a G35S that their exhaust comes with one. Like their muffler is dual stage. They are only a single exhaust, but the muffles has dual tips. At a low RPM exhaust is only coming out of one tip, at a higher RPM the other one opens up.

I'll see if he has any more info on this.

 

Straight dual tip exhaust with variable capacity muffler and chrome finisher and three-way catalytic converter with closed loop feedback


seems the variable capacity muffler is what i'm talking about.

 

All the performance edition nissans are running this dual action muffler now. I first saw it on the new SER spec V, it works pressure just like what joker wanted

 

OK I really looked into that electronic flaper system and it is an electric manual flaper system. It is great if u are running a dual exhaust system like it was origionally intended for. Ex, by-passing the cat to make a free flowing exhaust.

Now if someone wanted to go with a 3" exhaust on an N/A car it would be overkill. With an electronic flaper valve the driver would be able to get the best of both worlds. The electronic flaper system would keep the exhaust system 1/4 open then at a preset RPM would open the flaper all the way to allow for a 3" free flowing exhaust system.

Think about it, u'll still have low end Tq because the exhaust is restrictive at low RPMs, then high hp through a FF 3" exhaust.

That is a very nice flaper system. Too bad it is not electronic. The minimum that I would as from the valve would be to tell me how much open or closed it is.

If anyone's got any ideas on how to make it electornically controlled, throw them at me. I've got some ideas myself but have to run them by others that could confirm that it would work.








Juker008

 

I would be interested in doing something like this too.. The gains you could get from this mod seems very logical..

 

Yea the g35 utilizes this. It would be interesting to see what kinda hp/tq gains on the low end with this.

 

if anyone is interested i have a used on that i had on my tl that i would like to get rid of, its in perfect working condition, just need to take it to the muffler shop to get it installed unless your good with welding....pm me if your interested

 

Can you give a little more details on what kind of gains it produced on your TL? Any butt-dyno you like to share would be fine.

 

I don't want this topic to waste away...

asiankidd, what made you try this? what other exhaust mods did you have? did you just have it on one muffler? How much you looking for? Where are you located?

I think this, along with a CT B-pipe would show some low and high rpm gains for N/A folk.

 

The only way something like this could work would be to have a "Y" peice put infront of the muffler and then you could mount these in the other outlet so that the exhaust can flow out with our entering the mufflers. I don't see this doing anything good for the NA guys. Proper backpressure is needed to build proper power, which is why you can buy a univeral muffler for $30 and a tuned axleback or car back can cost up to $1000 dollars.

Although it might benifit titand19 because of his turbo

 

I disagree.

A FI system needs as much room to breath as possible. That's why ALL_MOTOR unbolted his exhaust when he did his 1/4 mile runs.

So this dual capacity exhaust system would be only for the NA folk.