FuSe 22 stupid question

[Good Soil (Pete)]

So I decided to see what diference the old Famous fuse 22 made. Did the usual man thing and didn't bother Reading the manual. First attempt made the engine stop working ....then decide to read the manual and found the famous 22 was in the boot and not in the engine bay. Took little ol 22 out and have to say I couldn't tell the difference.

Mmmmm that's odd thinks me. So laying down at the back of the car I found the exhaust flaps At the rear of the car and it would seem they are already open. Moving them definately seems to make he exhaust quieter. Are these the flaps controlled by famous 22?

So now for the stupid question. How does fuse 22 work?
I recall reading that over 4000rpm the valve should open everything up and the roar of a lion having a hot poker shoved somewhere should occur! Does that only happen if you are in gear? Blipping the throttle in neutral gives me a hearty roar but that's with famous 22 all in tact. Taking famous 22 out appears to make no difference to my exhaust flaps when in neutral. Think it might find it hard to drive and lay at the back of the car to check this when it's in gear.
Had a reasonable poke about under the dash and have not seen any switches that might control the exhaust flaps so I ruled that out.


What do you think?

[mikey k]

The fuse powers a vacuum pump that is used to close the valves.
No vacuum = open valves and nice noises
So with the fuse in you get the nice noise when you start up until the vacuum builds
Then again when the rpm goes over 4000 rpm.
There is a marked difference between the 4.3 and the 4.7 with the fuse out.
4.7's are a lot quieter at the bottom end

[rick-derby-]

Pete are the vacuum pipes connected to the valves they may have been what we term decorked rather than remove the fuse albeit the same effect

[Good Soil (Pete)]

Will check that out and see.