Interest in an active exhaust system?

[Brett]

Im only posting this as a guage of interest but would anyone be interested in an active exhaust system ie one that can be loud,dronny one minute and subduded the next. Im currently having a new collecter pipe made from stainless and the plan is after we have the jig made we make a few active set ups if people would be interested or even just a plain, straight through as Im having to begin with.

The plan is, two baffles are placed either end of the collector pipe with two diverter valves opening and closing to miss them. This will obviously be more benefitial to the QS Sport and Super Sport gang but will no doubt give the same results on others. As I say, a straight through, fully stainless tig welded collector pipe will also be on offer too should anyone fancy one of those. Once mine is done I'll post pictures.



Thanks

 

[Jamesv6]

Read up these a while ago after someone suggested it on here. I got lost of course as it was more technical than fitting a new air freshener, but I take great interest in reading thing I know nothing about.

I look forward to seeing yours.

 

[Rich]

Sounds fancy! Do you remember those cherry bombs around about 15 years ago that had a big arrow under the silencer (if you could call it that) that allowed you to choose how loud it went, you could make a 1300cc golf sound like a Vulcan bomber on the quiet setting.

 

[BenR]

http://shop.noweeds.net/main.sc

http://www.quicktimeperformance.com/QTEC/index.php

for the lazy.

 

[Brett]

Brett,

Excuse the naive question - but what difference does this make and what is the gain of doing it???

Tarr Tim

As far as a performance point of veiw is concerned not a great deal if any. However, for those of us with noisy Quick Silver Sport and Supersport silencers and other non standard systems, the possibilty of going from quiet motorway driving to manic howling at the push of a button or harder press on the throttle would be quite appealing. Many of the top Supercar manufacturers now produce them as standard too. Would also be very handy at certain track days.

 

[Jamesv6]

So basically it's like having a silencer down the track and something changes the points to change direction?

 

[Brett]

Exactly mate. The aim is to make one that will fit a completly standard car with out any modifications other than changing the collector pipe. This way pretty much all silencers will fit.

 

[alex020869]

Brett,

Are you gonna be doing this soon?????

I might be interested.

Alex

 

[Brett]

Brett,

Are you gonna be doing this soon?????

I might be interested.

Alex

Im having a stainless collector pipe and jig made up as we speak so it won't be too long. The idea is to use my car as a bit of a test bed for the active set up. If all goes well and it works how it should it will be offered to who ever wants one. My original idea was to modify a Janspeed silencer to run either quite noisy or stupidly loud but thought it be more beneficial to go from fairly quiet running then back to the usuall OMG sound. Mentioned it purely to see who would be interested.

 

[clarkeeuk99]

I may be interested. Excuse my ignorance, but am I right in assuming that the backbox is to stay the same based on what we all have?

Do you have a rough idea on how much this may cost?

Cheers,
Phil.

 

[Brett]

I may be interested. Excuse my ignorance, but am I right in assuming that the backbox is to stay the same based on what we all have?

Do you have a rough idea on how much this may cost?

Cheers,
Phil.

Yeah the plan is to have it fitting any vee with the usuall OEM silencer, Quicksilver silencer, Janspeed/K-tec silencer or any other replacement silencer. The only part that will be changed will be the collector pipe. It will be 100% out of veiw and un noticable until adjusted.

As far as price is concerned im not too sure at the moment. It will all be high grade stainless with mandrel bends and fully TIG welded so to ensure a brilliant quality part. The main cost will be in the valving/butterfly system and controls. This is what we are currently looking at.

 

[Jamesv6]

I need more help understanding this as I've got myself into what are probably daft thoughts about it.

Is it after the cats or before?
Does it just simply open and release some of the noise and gases into the air?
I'm guessing it will just sound like an exhaust with a big hole in it?
Will the ECU adjust to the sudden drop in back pressure when this is opened?
Does the car need what back pressure there normally is to run properly?
Is the engine management light going to come on permanently?
Will it be tied into the revs electronically or a manual 1930s style pull to open knob and cable system?

 

[Brett]

I need more help understanding this as I've got myself into what are probably daft thoughts about it.

Is it after the cats or before?
Does it just simply open and release some of the noise and gases into the air?
I'm guessing it will just sound like an exhaust with a big hole in it?
Will the ECU adjust to the sudden drop in back pressure when this is opened?
Does the car need what back pressure there normally is to run properly?
Is the engine management light going to come on permanently?
Will it be tied into the revs electronically or a manual 1930s style pull to open knob and cable system?

Q1. Is it after the cats or before?

A. This will replace the cats located in the collector pipe by two small mufflers/silencers. The entire exhaust will be kept other than the collector pipe which will be replaced so there will still be two cats left onboard.


Q2. Does it just simply open and release some of the noise and gases into the air?

A. No. This setup will switch it from using 2 baffles and a rear silencer to just the rear silencer on its own so all exhaust gasses will still flow through the tail pipes.


Q3. I'm guessing it will just sound like an exhaust with a big hole in it?

A. No. This is because it is still being silenced by the original rear silencer. So a QS Supersport will still sound like it should do but at the flick of a switch will be better suited for long haul motorway miles. Think of it as a way to quieten the car as opposed to making it louder.


Q4 & 5. Will the ECU adjust to the sudden drop in back pressure when this is opened?
Does the car need what back pressure there normally is to run properly?

A. There will still be ample ammounts of back pressure as the normal rear silencer is still in place. Will be no different from fitting full decats I should imagine.


Q6. Is the engine management light going to come on permanently?

This I'm not 100% sure on as yet but like I say, it will be no different to fitting Janspeed manifolds etc so I'm sure it will be easy to sort that issue out if it does occur.


Q7. Will it be tied into the revs electronically or a manual 1930s style pull to open knob and cable system?

A. Hahaha. No 1930 cable system James Lmao. Given that the cars are fitted with fly by wire throttle bodies, I'm sure there will be a way of linking the electronicaly operated butterflies to open at a set throttle posistion or a set ammount of revs. This will be looked into. As for now, it will be just a simple hidden sitch of some kind.

Hope that answers your questions ok mate. Like I say, I'm not doing this to make the car any louder or faster but quieter for those times a few of us get pissed off with a roudy engine behind us non stop. lol

 

[clarkeeuk99]

This sounds great Brett, thanks for providing us with all this information!

I'm definitely interested, so I look forward to hearing how you get along and the price.

Cheers,
Phil.

 

[Jamesv6]

Even more interested now.

Thanks Brett.

 

[Brett]

Been a bit behind on this recently but I now have a few very rough drawings of how the set up will fit and work. As a few of you may know, my first prototype will be fitted with the same pnuematic valves as fitted to the lattest Astons. However they are very difficult to get hold of so the next ones will be made by myself and a friend and will rely on turbo actuators to open and close them. Hopefully this will prove very reliable. more updates soon...

 

[BenR]

I dont want to seem like a stick in the mud, but how are you going to supply either vacuum for the aston valves, or positive pressure for turbo actuators, at the correct rpm point and on demand?

 

[Brett]

The system will always rely on the the vacuum of the engine so to begin with the Aston valves will work perfectly. If push comes to shove and I make another using easy to find turbo actuators, ill use the non standard type which I ran on my mini. They were fully rebuildable and would only need the spring to be placed on the other side of the diaphram (Which like an idiot I once did!) That way the actuators will work under vacuum and in the same direction as the Aston ones.

 

[BenR]

Ah, a rebuildable actuator, not a bad idea!

So the exhaust valve will operate purely on the basis of manifold vacuum? i.e its only closed at high vacuum (low throttle openings and on overrun?).

 

[MikeLarwood]

http://www.dmhperformance.com/ecutout.htm

Present.