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Childish popping flames on overun


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Every once and awhile the car pops a little flame out the back on the gear change, childish I know but fun. I was wondering if it is an easy task to make the car do it all the time on full throttle high rpm runs when changing gear? From a quick search it seems it may be to do with the overrun fuel cut and ignition retard but I'm unsure if its safe to have a dabble with these figures? If so what sort of changes is safe to make? or is it strictly a tuner only job? 

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So the flames coming out the exhaust are normally fuel passing through the engine unburnt and then igniting in the exhaust system. During the ECU's over-run fuel cut function the ECU turns the injectors off, so fuel will not be entering the engine. Normally the throttle is also closed, so reducing airflow and making the mixture in the exhaust richer. If you wanted to make this happen more often you could look at adjusting the fuel table numbers in the over-run area (high rpm, low throttle). You also want to make sure over-run fuel cut is turned off. You could also consider retarding the ignition timing when throttle is closed and engine speed is high.

The risk with doing these things is that the heat can built up and cause damage.


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