shooting form the exhaust

[Nik da Greek]

A lot of the bangs may well be down to fresh air being drawn into the exhaust system around dry joints by the pressure change when the throttle is shut off after being open. You get this a lot on slip-together bike exhausts held together by springs rather than flanges. The air is sucked in through the joints and because it has a higher oxygen content than the already-burnt exhaust gas it exites the hot fuel molecules in the exhaust enough to re-ignite, hence the pops and bangs. It\'s also why Bobbit\'s pops and bangs loads when the airpump pipe is connected, it\'s basically injecting fresh oxygen into a really hot place with lots of fuel molecules wafting about! That\'s the three sides of the "fire triangle", that is; heat, fuel, air.
 
Sorry about the boring science bit. It ain\'t funny but it\'s true!

[RedRummy]

Bobbit said his air pump wasn\'t pumping though...

[Nik da Greek]

Oh, yeah. Maybe I made it all up, then! :Laugh I guess it\'s still pumping air down into the area where the de-cat is, though,even if it\'s not got a pipe actually into the de-cat itself any more. So it\'s still introducing lots of cold, fresh air just where there\'s a really hot bit of the exhaust with a few joints to suck the air in through.
 
Or am I talking b*ll*cks? Again?

[Ricco_04]

The air pump \'injects\' air to 2 places.  One for the center cat and one for manifold so im told

[BenLewisMav]

Mine doesnt seem to pop and make a loud noise but it does make 4 foot flames pour out of the exhaust for about 3-10 seconds after letting off after boost.
Guess its coz the microtech doesnt have a decelleration fuel cut set on it (was told that when running premix only its best to make sure the engine is always getting fuel, -and therefore premix oil, under all conditions)
Great party trick

[Mart160plus]

Disconnect the air sensor, I got 16ft flames under the gantry at the Ring cos mine slipped off in the heat. Been held on with cable ties ever since !

Anyway, I got to drive through the Dartford tunnel in my rex today. Nuff said.

[Laursdahl]

My baby does the best job when im really am beating it in first gear and taking it to 2nd then there is a BIG bang...  And the best part is if im racing someone from a standstill it just makes the bang when the exhaust is just beside his side window.. Muaha some have been bitching about that

[James H]

Hmmmm wonder if my fc will still do it one the Rensis is in it, will be running with no cats on a 3" system.... lets hope so!?!