Exhaust Query

[CocoPops]

Can you have a "2 stage" exhaust?

ie could you have two routes after the manifold?
one routed through the silencer and cat, and the other straight thru

Would this work? Using some kind of solenoid to direct the exhaust flow?

then you could have the quiet oem style noise or Ear splitting performance noise

Is this even possible, I've had a think and I can't see why not if you could deal with the splitting/valve/diversion work.

[Crazy Cricket]

Yes, in a nutshell.

In reality you would have to find space for the extra plubing and get the thing insured. Bit of a pain in the bum, and the engine would only be really mapped for one config. Another mechanical route would be to have butterflys in the tailpipes to take the sting out of a rowdy zorst at low revs. I think it was the Maranello Ferrari fitted such a system to.

A better bet would be to see if anyone can make a two stage sliencer/s for the clio, these have a valve inside that gets diverted by the exhaust gasses themselves, when you are gunning it.

[IainB]

There is actually a kit in the good old US of A that opens up the exhaust so you go from having a nice silent option, to a straight through. It can also be achived (especially on V8's ) by having a removeable 'cap' welded to the downpipe, enabling a straight through manifold at the track, then re-fitted for the drive home

[XTR]

Mr Cocopops Mode (Loud ) vs Mrs Cocopops Mode (Quite)


Just tell her....... its your car... not hers

[CocoPops]

lol @ XTR.

nah I'm thinking:-

Town/MOT Pass
Ragging/MOT Failure

[Vimeous]

I understand a number of Jap motors have kits available for this. Moby-Dick knows a bit more about what is available.

For my motor the option is to have a cat-replacement section of the same length which needs to swapped everytime the MOT comes round, something I can't be bothered to do, but many more options are available for more common cars. Fingers crossed!

[Moby-Dick]

I'm sure I've heard of actuator kits that will re route piping. Failing that a lot of the large bore jap exhausts have a "bung" that you can put in which reduces them to quiet (ish) levels of noise

[schrickvr6]

sounds a bit like the old exxup exhaust systems that had a cone inside the system that would give more back-pressure thus more torque at low revs and would open out for full flow at high revs

[CocoPops]

Ohh, this sounds like it's possible then.
Just need to find some web examples then talk to an exhaust company to see if it's possible.

My current exhaust is a 4-2-1 manifold into Cat, then it splits into 2 pipes again then it has 2 seperate back boxes (one per tailpipe).

There's gotta be for more power some where.

[doll]

I doubt very much whether it will be possible on a 182 because of a number of factors, firstly, you would have to be able to changing the system mapping of the vehicle due to the changes in airflow and fuel, you would also be removing back pressure from the system so you would probably loose bhp as you're car would be designed to run with certain levels of back pressure. You would have to have some sort of mobile mapping system, laptop or something tho manually adjust fueling etc when you wanted to switch exhaust.
Another problem you will have is the twin Lambda sensors you have, I doubt very much that you're car would run unless gases are passing the sensors, as a twin exhaust system would redirect this. There would be loads of issues and problems imo, different if it was a ten year old car, when catalyst technology was in it's infancy. Personally I think you would be giving yourself a hole heap of issues and a lot of expense for very little (if not any) gains. You'd be better of seeing if anyone has produced a sports catalyst for the 182 yet, but even then I doubt the gains would be that great. Without turboing the F4 lump, I doubt you'll get much more out of it, 180 brake out of that engine is impressive as it stands.

[dkmech]

Wise words these, doll. Perhaps too wise? He is a witch!!! Burn him!!!

[Moby-Dick]

Dual mapping isn't that hard is it ? you can get chips for the 200 with two mappings on them which would accomodate that. You are correct about the labmda's though. I have a jap spec engine which was designed not to run with lambda's so the cats were removed without any problems ( for my lovley ,shiney , flamey mongoose )

Seems like you have the same problems with the clio 180 as the honda s2000. The engine has all the power its ever going to have (without forced induction )from the factory

[doll]

Dual mapping isn't that hard is it ? you can get chips for the 200 with two mappings on them which would accomodate that. You are correct about the labmda's though. I have a jap spec engine which was designed not to run with lambda's so the cats were removed without any problems ( for my lovley ,shiney , flamey mongoose )

Depends on which 200 you are talking about, if you are talking about a Rover 200, then you are talking about 10 year old tech, which I mentioned in my last post is quite easy to bypass. The emission system on modern cars is somewhat different, you mess with emmision output, it ain't gonna run! Hence why people have trouble de-catting them, and where people have tried generally they have not had much success on the release of extra bhp. The other issue there is as I said above the engine relies on a suitable level of back pressure (as well as reducing emmisions), hence the introduction of EGR valves for the recirculation of gases (to maintain consistant back pressure), you give it more flow the computer just takes it away again, lol.

[dkmech]

He be meaning the Nissan 200sx

[doll]

He be meaning the Nissan 200sx

Aah, that's different then, two staging turbo's is easy. 'X' boost or 'Y' boost, pick you're stage. Get yourself an in car boost controller, you can even play wheel of fortune, lol.

[Moby-Dick]

I had an in dash adjustable bledd valve on my old rover 820 vitesse which was quite fun if a bit spikey

the 200sx has an HKS adjustable actuator on at the moment , but its a bit of a mare to adjust - when funds allow I'd love an EBC , with scramble mode