blue flame exhaust when shifting and pop

[ChevyAveoRS]

hey guys,
i saw a really nice 350Z on hwy 7 in canada. When he was shifting at really high rpms his exhaust popped and a lil blue flame came out. What caused this i am really curious. Is it legal? Would the cops pull hime over fr it. its not the first tiem ive seen it ive seen this on a audi a4 b4 and a skyline once.

[aveodude]

are you serious?

[mikedudley17]

he may be runnin catless and runnin a bit rich. runnin catless is illegal (in the US anyways). so if thats the case... or maybe race gas. i dunno what makes all the diff flames on cars. i just know how to put a spark plug in my exhaust to burn the excess ****.

[ChevyAveoRS]

i had a civic befor nd ran it catles and no pop or blue flmes. Could it be teh turbo or nos??
i dunno

[mikedudley17]

was he goin fast?

if so, then yeh it was prolly the NOZZZZZ.

[ChevyAveoRS]

around 70km/hr nuttin crazy

[aveodude]

It is called backfire and it is because he is running rich and extra unburnt fuel is expelled out of the cylinder. Then it is lit on the way out of the exhaust due to high exhaust temps or a misfire. Normally happens during off throttle deceleration.

[ChevyAveoRS]

is that bad for the car??? can the cops give them tickets?? its looks really siick though lol

[mikedudley17]

if its stock then im sure there isnt much the police can do about it, plus its prolly not doing it all the time.

[aveodude]

no it isnt bad for the car and yes the cops can stop you for it because 99 times out of 100, the cat. converter is cut out.