27 Jan Crackle and Pop ECU Tuning
So what’s all the tuning buzz with the crackle and pop tune aka bangs and pops, popcorn, or burble tune? Why do they do it, and does it offer a performance benefit?
Well first off this tune is easily recognized by the telltale burbles and crackles heard during the deceleration of a vehicle. The main reason we’re seeing this rising in popularity is mainly because tunes like this make a car more fun for the driver.
a Crackle and pop tune is simply an adjustment to specific ignition timing, fueling and other ECU parameters in order to achieve the desired effect. Crackles and pops are created when an explosion occurs outside the combustion chamber in the exhaust system. Most modern vehicles have what is called a four-stroke engine, meaning that the piston has to move four times in order to make power.
As seen in the diagram above, ideally ignition occurs just after TDC (top dead center – where the piston is at the highest position of its stroke). Now for a crackle and pop tune, during the exhaust stroke of the cycle, the ECU parameters are changed so unburnt fuel is ignited when the exhaust valve is still open in higher rpm area of the load table and there is a low throttle demand, i.e. during deceleration after a full-throttle run. If done correctly the explosion will still be happening as the exhaust valve opens, letting the sound escape into the exhaust. That sound echoing through the exhaust is what creates the telltale crackles and pops.
Many people ask if this helps, or hurts the tune. Recently this has become popular because of the drama it adds to a car’s personality, but if done by an experienced tuner, it is mostly a euphonious sound modification. Similar concepts known as anti-lag is used to build boost on turbo cars, and 2 step also can help a vehicle stage for a race launch, however, the crackle and pop tunes aren’t usually designed with these things in mind. Keep in mind, that moving the exhaust event to outside of the combustion chamber isn’t consequence-free. The pressure and heat waves can put added stress on turbocharger turbine wheels, exhaust system components, and can rapidly cause a catalytic converter to deteriorate. That is why this modification is recommended for highly “modification experienced” car owners only on a vehicle that is not used on-road or subject to any laws that require meeting emission standards. On cars that do not have any catalytic converters and are straight piped, a crackle and pop tune often also results in some awesome fireballs. Check out the pictures and videos below to see some of our favorite firebreathers.
If this is something that intrests you, please feel free to contact us for more information. Through our partnership with HD Tuning, we are able to program crackle and pops tunes on most modern ECU controlled vehicles. Make sure to check out our previous blog post on ECU tuning so you can understand the basics!
If your looking to get that rollicking fun that comes with driving a crackle and pop tuned vehicle, we’ve got you covered! Give us a call at 630-305-3054, or check out our website www.fluidmotorunion.com.