Flames On Gear Change?

[Beaker™]

Seen a few cars emitting a flame at gear change or when 'backing off'. Am i right in thinking this is the ECU adding excess fuel into the cylinders on overrun in an attempt to keep things cool? And that the excess fuel then travels through the exhasut system (which is hot) and reaches the tailpipe (and oxygen) and ignites?

If so, is this type of thing built into the remap?

And is it advisable to run a CAT if your seeing flames? I know there shouldnt be much oxygen in the CAT but excess fuel could damage it right?

 

[ibizacupra]

usually a decat'd car and fuel on overrun igniting as you say. Unusual but unheard of on 1.8t's.... I know mine does it so I am told. (decat)

 

[Beaker™]

I see, so is yours mapped to add fuel on overrun?

 

[claudefrog]

most turbocharged cars run just that little bit rich to keep egt's down, so on over run you will get a few pops and maybe a bit of a flame if the exhaust is warm enough.. or you could be chavtastic and fit a flamer kit

 

[Beaker™]

or you could be chavtastic and fit a flamer kit

No thanks! lol

 

[Ant FR]

mine bangs really loud on gear changes if you rev it high through the gears.

not sure on flames though,

I do know that you can make any standard Cupra 1.8T flame really well if you sit and rev it up enough, saw a guy do it to his standard cupra up basildon one night, the whole exhaust system was glowing orange,

So doubt it was nay good for it but looked bloody good

 

[Ruddmeister]

I see, so is yours mapped to add fuel on overrun?

Bills car is running around 400bhp and a big turbo, infact it may be easier to list the parts that are still standard rather that list the mod's, I assumed you would have heard the legend of the Badger Wagon from Stonehouse seeming as you are only in Stroud?

 

[Beaker™]

Bills car is running around 400bhp and a big turbo, infact it may be easier to list the parts that are still standard rather that list the mod's, I assumed you would have heard the legend of the Badger Wagon from Stonehouse seeming as you are only in Stroud?

Yeah i know bill, very helpfull chap indeed

 

[ibizacupra]

I see, so is yours mapped to add fuel on overrun?

not sure how possible this is to fuel dump on off throttle as its something I want on it to help control EGT's. From my wideband A/F gauge I would say no it does'nt.... Where it might flame is from on to off to on throttle, blipping on change down into corners etc..

you would need to ask someone who was following me.
(did flames at the ring so I was told)

 

[Beaker™]

Interesting. Must have looked good though

 

[Ruddmeister]

not sure how possible this is to fuel dump on off throttle as its something I want on it to help control EGT's. From my wideband A/F gauge I would say no it does'nt.... Where it might flame is from on to off to on throttle, blipping on change down into corners etc..

you would need to ask someone who was following me.
(did flames at the ring so I was told)

That video clip of the Silver Ibiza with BT, from Combe, had flames changing up along the pit straight before Avon Rise IIRC......can't find it now though

 

[AlphaMale]

I know from Evo's that an Anti-lag for the turbo will cause a flame coupled with a Blitz exhaust.

Alpha

 

[ibizacupra]

That video clip of the Silver Ibiza with BT, from Combe, had flames changing up along the pit straight before Avon Rise IIRC......can't find it now though

one of these 2
http://badger-5.com/bin/movies/silver_seat_dvd.mpg

http://badger-5.com/bin/movies/duck_silver_seat_dvd.mpg

The car runs on Motec ecu, 3" single box exhaust and GT30R turbo...!

 

[Saul]

I know from Evo's that an Anti-lag for the turbo will cause a flame coupled with a Blitz exhaust.

Alpha

thats because with anti lag you basically dump fuel into the exhaust to keep the turbo spinning

 

[ibiza_95]

its mostly when you fit a decat and rev the thing to the limiter, when it starts bouncing at the limiter it pops a little and a flame may just appear in the exhaust, but this doesnt spit flames out like you may think, its usually just a flame which fills the exhaust

 

[Forbez]

Cossie's do it due to the way they are fueled when tuned, so that there's lots of petrol being used, which is dumped into the exhaust on let off after boost.

 

[andythom]

thats because with anti lag you basically dump fuel into the exhaust to keep the turbo spinning

Spot on.

Others do it just due to the fact that when your ragging it and lift of suddenly theres unburnt fuel in the exhaust....mixed with oxygen and heat and pop!!!

 

[psq43]

My standard LCR225 does it too at high rpm or when braking and changing down quickly! Cat Converter makes little diff as there is no actual ignition of gas at the front end of the system due to the very very high temps and the vapour being so hot making it harder to ignite! Once its gone past the cat into the cooler section of pipe and static from outside air and oxygen gets to it, then it fires up!

Had some concerns when was told by a fellow motorist this was happening so asked at the dealer and a turbo/injection garage and they both agev me the same answer!

Wont damage the cat as it ignites long after it has passed it!

Looks good(ish) at night too! lol

 

[psq43]

My standard LCR225 does it too at high rpm or when braking and changing down quickly! Cat Converter makes little diff as there is no actual ignition of gas at the front end of the system due to the very very high temps and the vapour being so hot making it harder to ignite (or some other technical gumph along those lines)! Once its gone past the cat into the cooler section of pipe and static from outside air and oxygen gets to it, then it fires up!

Had some concerns when was told by a fellow motorist this was happening so asked at the dealer and a turbo/injection garage and they both gave me the same answer!

Wont damage the cat as it ignites long after it has passed it!

Looks good(ish) at night too! lol

 

[psq43]

Ok, that a bit odd! went to edit and its posted same thing TWICE!!!!