Blowing Flames?
Senior Member
Joined: Feb 2003
Posts: 240
Senior Member
Joined: Dec 2003
Posts: 500
From: Minneapolis,MN
I 3rd that!
short and sweet....
On a turbo engine with the stock efi when you get on it and then let off the pressure in the intake manifold (after mass air flow sensor) is vented to the atmosphere from an aftermarket bov. The ecu still thinks that ammount of air is after the MAF so the mixture is rich which ends up as a flame out the exhasut.
On a NA engine its similar.
short and sweet....
On a turbo engine with the stock efi when you get on it and then let off the pressure in the intake manifold (after mass air flow sensor) is vented to the atmosphere from an aftermarket bov. The ecu still thinks that ammount of air is after the MAF so the mixture is rich which ends up as a flame out the exhasut.
On a NA engine its similar.
Senior Member
Joined: Jan 2003
Posts: 352
From: New York Long Island
its not that bad of a question. I remember when i was in high school way before any rx7s i never knew why either. Just cause some noob kid asks a question that you guys know the answer to doesn't mean u should just shoot him down. If you think about it, it's not that bad of a question for a noob, atleast there r real causes and effects behind the answer. Not like that guy yesterday with the stupid list of gay **** to do to his rx7 including a "flame kit". A great part about knowledge is that you can share it with others.
Rx7s spit flames from the exhaust due to a high amounts of fuel going to the engine, and some times some of the fuel isnt burnt and when it goes through the exhaust its set off causing a cool looking fire ball. Normally stock rx7s dont just shoot flames you need a big exhaust for less back pressure and a fuel cut defense helps also,,but isnt needed. you can do other things to let more fuel into the motor which causes more fire also but you really need a big exhaust. Most of the time u see a car spit flames when the dude shifts. the change in the rpm allows for less fuel to be used up by the motor. I normally get some flames when i shift to 3rd at high rpms, and most of my friends with 7s get the same.
now im not sure if all that is correct but whatever
Rx7s spit flames from the exhaust due to a high amounts of fuel going to the engine, and some times some of the fuel isnt burnt and when it goes through the exhaust its set off causing a cool looking fire ball. Normally stock rx7s dont just shoot flames you need a big exhaust for less back pressure and a fuel cut defense helps also,,but isnt needed. you can do other things to let more fuel into the motor which causes more fire also but you really need a big exhaust. Most of the time u see a car spit flames when the dude shifts. the change in the rpm allows for less fuel to be used up by the motor. I normally get some flames when i shift to 3rd at high rpms, and most of my friends with 7s get the same.
now im not sure if all that is correct but whatever
Member
Joined: Jun 2003
Posts: 34
Carrying on from racingxtreme's answer... my understanding is some rotaries shoot flames on shifts and deceleration as this is the leanest situation for an engine, fuel is the cooling agent in a engine so at this lean state the exhaust heats up enough to ignite the surplus fuel left over from the transition from normal mixture to lean when getting off the throttle.
