Saw this on ebay. Seems to be targetted towards the Nova and Saxo boys - cant think why.
It looks like a great idea. Every locost should have one.
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&category=43120&item=7922839571&rd=1
mine does that as standard
Oh dear god.... We should send emails to the bidders, telling them how said they are !
rrr... When I was a young engineer, we used to do this simply by switching off the ignition, flooring the throttle, and returning it to the top of the
travel ie no foot on the pedal, so you were on the overrun, then switch the ignition on. This filled the exhaust with unburnt fuel and then ignited
it.
Whay do you want a switch to do that for 20 quid!... Please send me your Tenners for this useful tip that will just save you a tenner!.
Downside is, it can destroy the exhaust... as we did this several times in the company Van.
The garage mechanics got wise to these over expanded bloated at the seams exhausts!... but it was fun... now I am older and wiser, and not so sad!
Moral of the story is you have a nice expensive stainless steel pipe and box... this can blow it out the water.!!
Geoffw.
That trick doesn't work on modern injected cars as turning the ignition of kills the injection.
I assume this device will just cut power to the coil pack and as you said allow unburnt petrol to pour into the exhaust.
It says may require removal of your cat. Damn right after you've knackered it with unburnt petrol and you fail the mot.
Having a propane tank blast gas into your tail pipe over a spark plug gives a much better effect and the only damage you do is to the bumper of the
car behind 
quote:
Having a propane tank blast gas into your tail pipe over a spark plug gives a much better effect and the only damage you do is to the bumper of the car behind
A friends car ground to a halt one day and he couldn't restart it. After churning it over for a few minutes it gave an almighty bang and the car jumped, people came running out of shops to see what had happened, he sat in the car as white as a sheet almost crapped himself. When we got the car home it had melted an exhaust valve and the explosion had blown the front box to pieces right under his seat.