Before my gps could show 110 kph : by 105 kph, exhaust noise already started increasing fast with rpm, even when I'd replaced the original 7 carbon-core * with 6 medium efficiency ( ~300 ohm per ft ) * & 1 high efficiency ( 0.2 ohm per ft ) * between transformer coil & distributor. If the original 7 * were still used, then likely noise would start to rise fast by 100 kph. In 1980 I already could buy medium efficiency *, but manufacturers in '94 still used cheapo carbon-core * because buyers have no chance to test drive on highway @ such a high speed, so cannot notice this inadequacy. My honda F20A ( 1 coil & distributor ) too had this problem : noise rose & torque dropped fast @>3000 rpm ( 100 sparks per second ) even when medium efficiency * & no-resistor plugs were used. Only after I fitted high efficiency ( 2 ohm per ft ) *, did this problem on highway end. Users of these single coil engines on highway @ high speed, better fit high efficiency *, unless their gear ratios are low enough : e.g. Hyundai Sonata @ 110 kph ( per speedo ) needs just 2500 rpm.
- posted
14 years ago