Chris,
I've considered twin plug vs. single plug etc. I do not have experience regarding the driveability etc. ...others have way more experience than I do. But, one of the things that I was considering was/is the increase in HP per compression point. Here is a link to a handy compression/HP calculator. I've included a sample of the results for a 250 HP engine at 9.5:1 and the results of bumping the comp to 10.5:1. Does this jive with real world results? Hopefully, Steve and other experts in the field will check in and let us know. At the time I was considering this, I decided that the increased complexity of twin plugging was not worth it for a
street car and I went single-plug and 9.5:1 JE's.
That's just me....I could be wrong
Compression Ratio HP Determination Program
Bowling's Compression Ratio -> HP Calculator
Computation Results:
Engine Horsepower (peak) is 250
Old Compression Ratio is 9.5
New Compression Ratio is 10.5
Computation Results:
Computed New Engine HP is 257, a 3 percent change