Active Exhaust Cutout Valves - now with videos!

[Rusty]

Tunnels are now hilarious

[nip]

Tunnels are now hilarious

Why not have a screamer pipe, my mates got one on his 500hp 200, it sound awesome

[Rusty]

I don't really need any more noise Screamer pipe can't be turned off and the car is now my daily driver

[re2500]

Another butterfly for a screamer diverter!!!

[Rusty]

If you had an unlimited budget then, yes, that's a good ideal but it all adds up... Be best off using a boost operated valve for that one and would be cheaper too. There was a good 3 hours' work to fit the valve on mine, which was included in the price but if you supplied your own and paid by the hour, then it might get a bit pricey unless you're a very good customer...

[SteveH]

I had the pleasure of hearing this in the flesh today, very nice indeed

[Rusty]

I was wondering how long it would be before there was a 'review' on here

POWER!!!

[SteveH]

It gets the thumbs up from my lad too! I'm going for a side exit with a single box after hearing yours on WOT

[Rusty]

That's just silly I'll send you some links about what you should do.

Yeah, he and the R32 that couldn't shift the white whale from its rear bumper were both impressed I'm sure

[Jack4688]

Just discovered this thread, I am going to have to get one of these!!! How has it held up after 2 years of use?

[Rusty]

It's been fine except for having to get a replacement valve, following a track day 2 years back. This was done, without fuss and under warranty, so once again A1 service from Charlie at Prospeed.

My conclusion is that the valves don't like being turned on and off unless the engine is at idle and so I have only opened or closed it after allowing it to cool for 10-15s after any WOT action and only at idle. It's been A1 since then.

With that in mind, it's not something that you can run with a boost threshold activation, unlike the vacuum / boost activated valves and it's slower to react too.

The option of having the car sound like an S1 is great but if I was doing it again, I'd have the exit at the rear, rather than under the rear seats, to avoid some unwanted resonance in the car. Most people love the mentalness of it but also comment that it's a bit crude.

I'm certain that with a little thought and a small inline silencer, you could fit one of these and make it sound loud but also tune that noise a little. No reason not to keep the OEM backbox, if it's in good condition, so you can have the best of both worlds.

[Thuppu]

I have been thinking of a control valve setup like this, because I have much room above the rear silencer. Main reason is to make less noise and drone while driving on highway, and to avoid waking up my neighbours at 5am in the morning when I go to work.

[Rusty]

With that setup, you're unlikely to need 2 silencers as the gas will flow through both tubes. Porsche bypass silencers with a smaller bore pipe, I guess to tune the sound as a portion of the gas still goes through the original silencer. It is the straight through portion that contains the valve.

[Jack4688]

My conclusion is that the valves don't like being turned on and off unless the engine is at idle and so I have only opened or closed it after allowing it to cool for 10-15s after any WOT action and only at idle. It's been A1 since then.

Sound advice

The option of having the car sound like an S1 is great but if I was doing it again, I'd have the exit at the rear, rather than under the rear seats, to avoid some unwanted resonance in the car. Most people love the mentalness of it but also comment that it's a bit crude.

I think I'd have to go for the middle of the car. I've been wondering how to increase noise without just chucking it out the big hole at the back. The solution came to me in May when the rear half of my exhaust fell off after a splash through a puddle. It sounded insane and I had the biggest smile on my face that I can remember. Frankly it was disappointing that we fixed it the next day

Then up until a few days ago my turbo wasn't fully clampled down onto the downpipe and made a similar noise, with just a touch of sanity. After a while I got bored of the constant howl from the engine bay, although it was still fun when I drove close to a wall

This seems like the perfect addition to any sporting car - mental when you want to impress your mates and frighten old ladies and civilised when you set off for work at 6am

[Thuppu]

With that setup, you're unlikely to need 2 silencers as the gas will flow through both tubes. Porsche bypass silencers with a smaller bore pipe, I guess to tune the sound as a portion of the gas still goes through the original silencer. It is the straight through portion that contains the valve.

The plan was to keep the valve closed at normal easy driving, so the exhaust gases goes only thru the 2" silencer, and will propably be a lot less noisy. Then under WOT at 0,5-1 bar the valve opens up and gases flows free thru the 3,5" silencer. Well of course some gases will go thru the smaller pipe as well, but that makes no harm..?