Astronomical boost + direct exhaust = Bigass backfire on dyno run.
What is 'Backfire'
- Any combustion taking place outside the engine cylinders will most definitely cause backfire. Car backfire is a very common problem. The symptom in the form of sudden burst of flames may make it seem as a very drastic fault, but is caused because of the simplest of faults as listed below.
- Cross placed spark plug wires could automatically set off your ignition timing and cause a power stroke ahead of time and cause backfire. Therefore it is always necessary to know which wire fits in which spark plug, and marking these wires while disassembling a vehicle is vital. The chords don’t have to necessarily swapped at the engine head as they can be jumbled up even at the distributor. So check twice.
- Poor Ignition timing is one of the most frequent reasons that causes backfire. For those of you who are new to the term ignition timing, Ignition timing quite simply is the timing set in for your power stroke. A power stroke is an explosion in your cylinder that causes your crankshaft to rotate essentially rotating your engine. Poor valve timing causes opening of the exhaust valve while a power stroke is in order thus allowing the explosion to run through the exhaust manifold.
- Bent valve facing is seen more in older cars or cars that have been running for quite some time. In this scenario ignition timing does not quite matter as no matter what you do, the combustion will escape the cylinder owing to the bent valve which will act as a leak in the cylinder.
- Excessive valve clearance is not a very likely fault, but it is quite possible. Valves are designed to open at certain strokes and remain shut on others. If the valve timing of your car is improper an unlikely valve clearance could occur and cause backfire.
When troubleshooting for car backfire always do so in the chronological order of the given sequence of steps listed above. You don’t want to check for bent valves before checking if your timing is of, simply because if you are facing backfire because of switched spark plug chords and you are trying to diagnose bent valves, you will end up dismantling your entire engine head for nothing. So do follow this order as given and you should be sorted.
Backfire is a serious issue and should be dealt with immediately. The engine cylinders may be accustomed to hot flames, but the rest of the car isn’t. Untreated backfire will definitely lower your bhp and could also damage your engine severely if left untreated for a long time.
