acoustic engineers

[Rocket Man]

i have just visited this local exhaust manufacturer ( http://www.powervalve.co.uk )
they had a good look over my Atom with the possibility of developing and making a new stright through exhaust. it was pointed out to me that it can not only be done but performance can be increased by introducing a performance cat ( they told me it can give more performance with a performance car than just not having one )
they said it could be also tuned to provide a characteristic sound.
all sounds good but still waiting for the costing.
i have told them it would have to look good, sound good, and be a sensible price. they can also provide a polished or brushed finish to the exhaust.
i know that Will (meladdo) Young knows these people personally so perhaps he will chip in a coment.
i have been askd to gauge any interest there may be out there for such an exhause produced for a " reasonable " price

[Oli1122]

I did remap my car in march and we tested different settings to see where you can gain additional hp.

The difference between 200cpi sports cat and the decat pipe on my car where +2hp and +5nm in favour of the 200cpi sports cat. Even on remapping process the car with decat pipe was not better at all times. For me not worth the hassle mot/tüv. The only good thing is the weight saving on the decat pipe.

Just for additional information (has nothing to do with the topic):
We also tested various intake systems (standard, different "dryer hoses", longer pipe, shorter pipe (ram intake). On my n/a car the longer pipe gave more hp (about +4hp) but lost nm in midrange (-10nm) but gained hp in high rpm range (+2nm).
I left it stock and replaced the org. dryer hose (innerside was not smooth) for a flexible pipe which is absolutely smooth on the inside. With this I gained 2hp on top but no loss in the midrange nm.

Next thing to do is to swap to a better intake manifold, going back to a smaller throttle body and a new exhaust backbox. I will also modify the exhaust manifold exit with a tapered pipe. I hope that the Venturi effect will accelerate the exhaust gases. But you need a free flowing backbox first so i'm quite interested how this works out.

For me the exhaust sound/ loudness can be absolutely stock. I'm not interested in a screaming exhaust I only want the power.

But thats me and the above mentioned testings apply to n/a cars.

[meladdo]

Indeed, I do know Nige and things must have changed as he has never been remotly intrested in developing a pipe for the Atom, intresting, I will have a chat with him