Join Date: Jul 2006
Location: Valrico Florida
My past experience with a normally aspirated engine revealed less spark lead was necessary after added the second plug. The dyno proved it. If you think about it, you're starting two flame fronts in the same combustion space - therefore taking less time to develope maximum cylinder pressure. Sand Man stated his results were similar relative to stock. The engine I experimented with had as much as 35 degrees lead in single ignition form. The end result after adding the second plug was 20 degrees total @ WOT. Both CHT & EGT went down with the second ignition installation. Mid-range power was the most noticable change in power.
'77 930 turbo Garretson I/C 1 BAR spring, (2) '82 Triumph Bonneville Royal Wedding Edition
Past rides: '74 914 1.9 liter twin plugged track car, '83 928S, '87 924S, '75 911S w '78 ROW 3.0, '72 911T, '70 911T and various other insignificant domestic examples. Happiness is a grey tailpipe! Turbo lag......it's worth the wait!