Exhaust cut out valve

[John Dixon]

Bought this to fit to the V8 conversion.
Basically having one quiet exhaust then open this to an unsilenced tuned length tailpipe under ECU control (rpm/load). Position will also switch maps.

 

[ZHead]

Forgive the Janet and John Blue Book 1 questions but I am keen to listen and learn here .....

Does this mean :

1 You will run two exhausts ?
2 Only one will be in use under gentle load ?
3 When under heavy load a straight through pipe will open up ?

I can see how that would affect the sound but surely the change in exhaust would change the engine characteristics ? Would that mean a progressively changing map to compensate for the exhaust differences ?

 

[John Dixon]

1) Yes
2) Yes
3) Yes, but it will probably be an rpm / throttle position switchover. Will have 2 maps that change as the valve opens / closes. It will make a pretty big difference I think as the cams I'm running have 60 degree ovelap @ 50 thou.

 

[ZHead]

Electickery Technology of the Devil.... I love it

Whay have you chosen to go down that route as opposed to just two pipes ? Is it to get the sound you want or do you see power / driveability benefits too ?

Surely you will not end up with a true dual exhaust system as in the traditional ka poh ka tah poh ka tah sound ? It would be more like a single exhaust system that just gets louder and growls more ?

 

[John Dixon]

Went with it so I have a quiet system for around town etc to avoid embarassement then an open system for the open road. There will be more power running the open one, but I'd probably get arrested driving around with it all the time!
Didn't want a dual system, I actually prefer the sound of a V8 through a single pipe.

 

[ZHead]

So are you planning to have what looks like a dual tailpipe but is in reality two seperate pipes ?

I have to say, I had never heard of it being done the way you are suggesting but it makes a great deal of sense

 

[John Dixon]

Will probably be one exit at the back and one side exit as the tuned length will probably only be ~1m or so from the collectors.

 

[ZHead]

OUCH !!!! Very loud and aggressive under heavy load then ?

 

[John Dixon]

Certainly hope so

 

[Russ]

Cool! Even Kitt from Knight Rider never had one of these!

 

[racer]

Great idea John. Could also be very usefull for passing noise checks at Track days!