Active Exhaust and Induction System

[Will Eastman]

Right I sure this will divide opinions but here goes it is an idea that I am interested in and think would improve the 182 in my eyes, and also I like a project.

The car currently has a full scorpion exhaust system and standard induction system.
I find the car is a too boomy when driving unspiritedly or with the girlfriend, but find the note of the exhaust to be not sporty enough to when driving spiritedly.
The valves would be operated by a switch added to the panel where the cruise control and traction control is located.

Induction system
A Y piece
B Relocated acoustic valve or other electric throttle body
C Standard airbox
D Cone filter

The acoustic valve will be operated by a switch (with the valve being open in sport and closed in non sport)

Exhaust system
A butterfly valve
B Cat
C Silencer
D Backbox
E (possible butterfly valve)

Again the valve/s will open when in sport and close in normal.

Right now a few questions for you guys...
1)What are peoples views on this set up in terms of viability and how it would sound.
2)I have not addressed how to make the car quieter (less boomy) in non sport mode any ideas on how to do this?
3)Would I be able to use a fly by wire throttle body for exhaust valve?
4)Would I be able to reuse the standard clio acoustic valve using a switch to open and close it?
5)Would a valve cutting off one of the two tailpipes quieten the car much and would it make the car run rough?

Thanks for reading this, I'm sure a lot of people won't like this idea but all feedback is appreciated, cheers

 

[Knuckles]

Sounds interesting.

mk3s have a similar induction set up as standard, with the second feed coming into play when pushing on.

and there's a bloke who has fitted an electric back box to his super 1600 replica, flick a switch and it goes from subtle to race car. I'll dig it out

 

[Knuckles]

Can't find the vid but it's in here somewhere

http://www.cliosport.net/forum/show...-WILLIAMS-IV-(Australia)&highlight=Super+1600

 

[Will Eastman]

Ah thanks looks interesting. Looking at some systems used on high end performance cars to get some ideas.
Is the mk3 clio (i assume 197) induction set up similar to the acoustic valve one on 182s, do you know how I would be able to manually control this with flick of the switch rather than through the ecu depending on rpm?

 

[stokie4ker]

I doubt a throttle body will be able to hold back the pressure of the exhaust gasses and the heat will probably kill it too.
You'll want something like this instead. Should be able to source one from a motorbike breakers easy enough.
Going to a straight through pipe exiting below the car might not be good idea. There's going to be an issue with fumes coming into the passenger compartment and the heat may damage something.
The adverse effects it would have on scavenging might be something to think about too.

It has been a few years since I removed the acoustic valve in my Clio but I seem to remember it not being very wide, certainly not as wide as the throttle body.
Instead of using a FBW throttle body for the exhaust you could use it for the intake instead but remember that you need a decent length <insert joke here> for good power.
Relocating the battery to the boot and moving the ECU should give you room to have a direct feed into the throttle body yet allow the second intake enough room to give a decent length.

 

[Tr1umph]

If your doing it your self they have some of the exhaust vavles on eBay search: exhaust control valve.
Or you could go to pro speed in Cardiff they do custom exhaust with butterfly vavles and also make custom intakes.

 

[Will Eastman]

Well I understand the issues wrt heat being let out under the car, I would consider routing it back into the system later on, so it acts as a bypass system (missing out silencers and/or cat).
Surely a throttle body would deal fine with the heat (as it gets quite hot in the engine bay). I can see the electrics possibly failing but the body and butterfly should be ok. Also the pressure wouldn't matter as the throttle body's butterfly pivots about the middle meaning the force opening it would be equal to the force closing it.
Yeh I have thought that space is tight meaning that battery relocation may be necessary.

As the sport mode (loud) will be when I'm driving more spiritedly I will have to ensure I do not loose (much) power with any of these mods.

I think possibly the biggest issue will not be making the car louder but making it quieter, anybody got any ideas on this?
Tr1umph, cheers, I have just sent an email over to pro speed

Cheers for the help

 

[1812lsd]

http://www.cliosport.net/forum/show...w-this-works&p=9916398&viewfull=1#post9916398

 

[MartinR]

I don't mean to sound rude but its a clio. either drive a 2000rpm nice and quiet or hoon it around above 5000rpm for noise.

The idea you have come up with is a good one but it will never work.

 

[GrahamS]

In this mighty car mods video they have a valve system exhaust

http://www.youtube.com/watch?v=VUL-6wsk7co

 

[Will Eastman]

Cheers, think that I would go for an purpose made electric exhaust valve. Unfortunately probably have to get it shipped from USA.

Does anybody have any idea what the internals of the single backbox scorpion exhaust look like? Have been looking at home manufacturers do this and would like to do it a little more professionally than just a straight out pipe so will need to know the route the gases currently takes, anyone?

 

[stokie4ker]

Well I understand the issues wrt heat being let out under the car, I would consider routing it back into the system later on, so it acts as a bypass system (missing out silencers and/or cat).
Surely a throttle body would deal fine with the heat (as it gets quite hot in the engine bay). I can see the electrics possibly failing but the body and butterfly should be ok. Also the pressure wouldn't matter as the throttle body's butterfly pivots about the middle meaning the force opening it would be equal to the force closing it.
Yeh I have thought that space is tight meaning that battery relocation may be necessary.

As the sport mode (loud) will be when I'm driving more spiritedly I will have to ensure I do not loose (much) power with any of these mods.

I think possibly the biggest issue will not be making the car louder but making it quieter, anybody got any ideas on this?
@Tr1umph , cheers, I have just sent an email over to pro speed

Cheers for the help

It may get hot under the bonnet where the TB normally lives but exhaust gas is VF HOT. I seriously doubt the electrics within the TB would survive.

As you want it loud but not LOUD it might be an idea to have the output of the cat modified to 2.5" and have the take off for the valve after the centre box.
Bin the Scorpion back box and have a box fitted that has one exit then have a pipe from the valve going the the other cut out in the bumper. That way it will look normal from the back but when the car is in quiet mode the exhaust gasses only come out of the left exhaust and when it is loud the gasses come out of the right exhaust but you will have a small amount of silencing.

Cheers, think that I would go for an purpose made electric exhaust valve. Unfortunately probably have to get it shipped from USA.

Does anybody have any idea what the internals of the single backbox scorpion exhaust look like? Have been looking at home manufacturers do this and would like to do it a little more professionally than just a straight out pipe so will need to know the route the gases currently takes, anyone?

That exhaust valve on ebay looks the job but £970 ? Are they serious?
Have a look at this one from the USA for $90. You'll have to pay shipping and import tax but I doubt it will come to a thousand pounds.

 

[Will Eastman]

Yeh have been looking at lost of those, there seem to be a few people who make them in the US and a few from China. I am a little worried (backed up from reading online) about how the electric switches will stand up to the heat and weather. The other option is to go with a pressure actuated butterfly ie. as here as this is what all manufacturers seem to use. I am unsure how they are controlled with the flick of a switch though as the only way I can see them working is by using the building inlet pressure with revs (is that the correct way :S).

I like the idea of that, would I be able to make that single silencer very quiet do you think as that would be a cracking solution.

 

[stokie4ker]

Even better price on this one. About £70 shipped to the UK.

 

[Will Eastman]

I think that one really could be s**t though.

 

[Will Eastman]

If I went cheap,
http://www.aliexpress.com/item/2-5-...alve-High-Motor-Brand-New-2-5/1131324152.html
I make it £38 plus any tax...

 

[stokie4ker]

Yeh have been looking at lost of those, there seem to be a few people who make them in the US and a few from China. I am a little worried (backed up from reading online) about how the electric switches will stand up to the heat and weather. The other option is to go with a pressure actuated butterfly ie. as here as this is what all manufacturers seem to use. I am unsure how they are controlled with the flick of a switch though as the only way I can see them working is by using the building inlet pressure with revs (is that the correct way :S).

I was thinking the same thing with an electric motor stuck under the car but it shouldn't be too difficult to knock together a shroud using some thin alloy or stainless steel. Don't know how the pressure actuated ones work but I'd guess it was a vacuum from the intake manifold with some inline valve to operate the exhaust valve.

I like the idea of that, would I be able to make that single silencer very quiet do you think as that would be a cracking solution.

The 172 only has the one rear silencer and some of the systems for them are pretty quiet.
Do you have the single backbox Scorpion or the RS192 with two back boxes?
Could whip the offside box off and stick a rag in the hole to see how it sounds on one box then swap the rag to the box and see how it sounds with no back box.

I think that one really could be s**t though.

It's the same switch that Varex use on the silencer fitted by @RiccardoAUS to his Clio Super 1600.
The pipe work does look a bit pony mind.

If I went cheap,
http://www.aliexpress.com/item/2-5-...alve-High-Motor-Brand-New-2-5/1131324152.html
I make it £38 plus any tax...

Trouble with that is making the flanges and pipes.
I'd go for a kit with all that supplied myself.

 

[Will Eastman]

Yeh I think I will probably get the pipework done by a professional so is probably worth spending more on parts to make their job easier.

No I have a single back box system, I would be most worried about the heat issue with the electric motors.

Do you think there is scope in using a pressure valve as this would give really good reliability as it is a decent OEM product. If I found how to control it *anybody* then I think this could be a nice OEM-ish solution.

 

[1812lsd]

That exhaust valve on ebay looks the job but £970 ? Are they serious?
Have a look at this one from the USA for $90. You'll have to pay shipping and import tax but I doubt it will come to a thousand pounds.

Probably out of stock, so instead of relisting they just put a crazy price on it.

 

[Cup_Phil]

Induction - pointless

You won't get any extra power, the standard airbox isn't restrictive and it's well designed. You'd get a little tiny bit more noise but certainly not worth the effort

The exhaust has been done quite a lot on high power cars - standard silencers and cat for MOT and driving around normally, with a straigh through bypass for more power

However on a normally aspirated 2.0 clio you would lose power and the noise would be absolutely unbearable.


It's a nice idea but utterly pointless

 

[Will Eastman]

I understand where you are coming from and maybe the induction is a little pointless.

In terms of the exhaust I would make it so that it runs a VERY quite (well as possible) system when closed but runs a sportier note when opened up (probably not all the way as I can see this not sounding good).
Do you really think this proposed set-up would loose power on say 50% opening.


or possibly like this...

 

[MartinR]

Induction is dead in the water imo.

But the exhaust idea could work i think.

 

[Cup_Phil]

If you're wanting to do the exhaust just for noise then it would work - but put the valves after the cat and first silencer because TRUST ME decatted straight through on a 1*2 sounds like the world is coming to an end

What would be really nice would be to put a very free flowing rear silencer on that gives the car a loud/sporty noise - then put valves in the actual tail pipes around 3-4" before the tip. Have the valves open from the reading of the throttle pedal. Obviously with a min 20% or so so they never fully shut.
That way as you drive around on part throttle it'd be all quiet - then when you nail it you'd get the noise.

A lot of ferrari/lambos and stuff do that these days.

Would be quite expensive to do though!

 

[Cup_Phil]

http://www.ebay.co.uk/itm/EXHAUST-S...arts_Vehicles_CarParts_SM&hash=item4d0e1dbc1b

Something like that (though not ideal size) would work

You've got me thinking now - would be quite a cool solution for a track car. I looked at bungs to reduce the noise of mine for 95db days but they sap power - with that you could have it shut on quiet days and open on louder days lol

 

[Will Eastman]

If you're wanting to do the exhaust just for noise then it would work - but put the valves after the cat and first silencer because TRUST ME decatted straight through on a 1*2 sounds like the world is coming to an end

What would be really nice would be to put a very free flowing rear silencer on that gives the car a loud/sporty noise - then put valves in the actual tail pipes around 3-4" before the tip. Have the valves open from the reading of the throttle pedal. Obviously with a min 20% or so so they never fully shut.
That way as you drive around on part throttle it'd be all quiet - then when you nail it you'd get the noise.

A lot of ferrari/lambos and stuff do that these days.

Would be quite expensive to do though!

Not sure what you mean by decatted straight through sounds bad? Do you mean having an outlet straight after the manifold (before the cat) would sound bad? I've come round to this now.

http://www.ebay.co.uk/itm/EXHAUST-SO...item4d0e1dbc1b

Something like that (though not ideal size) would work

You've got me thinking now - would be quite a cool solution for a track car. I looked at bungs to reduce the noise of mine for 95db days but they sap power - with that you could have it shut on quiet days and open on louder days lol

This probably wouldn't work as the valves take about 5 secs to open so wouldn't be able to be throttle actuated, for this you would have to go with a pneumatic system.

 

[Cup_Phil]

Not sure what you mean by decatted straight through sounds bad? Do you mean having an outlet straight after the manifold (before the cat) would sound bad? I've come round to this now.

Yes - like 110db "ow my god my ears are ringing" noise. It's horrid.

This probably wouldn't work as the valves take about 5 secs to open so wouldn't be able to be throttle actuated, for this you would have to go with a pneumatic system.

I'm sure that's just down to what valve you use. The throttle body on 1*2's is electronically operated and works fast enough to match the throttle position

 

[Will Eastman]

BTW I have just been speaking to Charlie at Pro Speed in Cardiff about a stand-alone backbox set out similar to the first picture above. He said he can do it and they have the valves (though not currently in stock) so thats some progress.

 

[Will Eastman]

Having another thought, do you guys think there would be room for two pipes in the exhaust, think this would be cheaper.
The yellow box is a new much quiter silencer.

 

[MartinR]

not unless you decrease pipe bore size. but it will cause performance problems then.

 

[stokie4ker]

Having another thought, do you guys think there would be room for two pipes in the exhaust, think this would be cheaper.
The yellow box is a new much quiter silencer.
View attachment 107331

The cat bolts onto the manifold so unless you want to risk ruining it I'd stick to having the bypass pipe after the cat. There is very little room between the cat and the centre box either which is one of the reasons I suggested having the bypass after the centre box.

 

[MartinR]

Excuse my drawing lol.

Both these have side exit exhausts first one i would say it will be quieter due to going through a centre box first.

The second just goes through the cat and out the side, will be loud and brutal. red line is the valve,

 

[Will Eastman]

Been into a garage to have the exhaust system looked at and the car checked over. I found out something rather anoying. The scorpion cat that was put in new a month before I bought it was not only put in the wrong way (180 degree out) with lambda pointing wrong way, but it was also welded onto the centre section. So now even if I wanted to pop on a decat that I have lying around its over an hours work in a garage.

 

[Chi]

Thats sucks

 

[MartinR]

How the hell can someone put the cat on the wrong way round lol.

 

[Will Eastman]

I duno, I'm not sure who fitted it but have got a reciept for the sale of the cat from Roadruner Motorsport, but no labour costs. Amazing how somebody could do that to a brand new £400 cat.