what's in a "performance" ignition coil compared to standard? <-- I'm not doubting it just wonder if the wires are a bigger or heat shielding takes more? a spark is a spark right?
I'm not an expert in this topic by a long way, but as i understand it you can get varying strengths of spark, which effects it's ability to jump across a larger gap, or it's resistance to being blown out by high boost.
If a spark is weak it could potentially fail to jump across a larger plug gap as plugs age, or at higher boost the weaker spark can be blown out much more easily.
it's possible to increase the swell, or coil-on time in the ecu, which basically charges the coil for longer before firing, but then you can burn out coils by running too high a dwell.
The TFSI coils I'm upgrading to are said to produce a stronger spark and can work over a larger gap.
Having said all this, the car drove brilliantly this morning with the new plugs!
Here's a little log I took on the way in:
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21psi at 4400rpm without VVT, slight dip to work on, but then a nice 22psi at 7200ish rpm before I ran out of road.
AFR isn't too bad, and timing is at a nice safe 18.5 degrees here.
No Hint of knock, and no WMI turned out yet at all, so I think we're in a good place.
69% duty cycle on the FID1000's is seeming fairly consistent across all pulls, and from the calculators I've found suggests we're well into the 400's.
I also borrowed the works Noise meter today, after not realising we owned one!
It has 2 settings based on the background noise and expected result, so I tested it on both to be sure of the result and worst case sound level.
dBA Low is for 35-100dB levels, and recorded 90.8dB at 4500rpm, taken at 0.5m 45 degrees from the exhaust, exactly as they test on a track day:
dBA High is for 65-130dB, and this test gave me a result of 93.8dB
Very happy with those results. it means I'm perfectly safe for Castle Combe next month, and should continue to be fine for most UK tracks. It also means that a large centre silencer should EASILY bring it in under 90dB for places like Thruxton.