Thanks for all the replies.
On 91 octane, for major production cars, I think the highest factory compression ratio for a FI motor is 10.5:1, and apparently that is pretty high. Motors like the Evo are around 9. They make up for it with high amount of boost, but this is safer than less boost and higher compression. It may also be better for turbo efficiency.
But to focus on that first point, how can the 86 with a 12.5:1 compression survive at all with boost on pump gas? Thinking of Boyles Law, my basic understanding says that compressing air can be much more dangerous than adding more air. Because pressure builds exponentially as volume decreases, compressing the volume a lot can result in huge buildups of pressure, but adding more gas to a larger volume won't add exponential pressure:
For that graph, going from a volume of 15 to 10 units meant a 20% increase in pressure from 100 to 120 units, a change of 20 units, yet going the same five units from 45 to 40 seems to only change the pressure from 30 to 35 units, maybe less than that. Depending on what the curve for an engine looks like, a change from 12.5:1 compression to 13.5:1 or to 11.5:1 could be a much greater pressure differential than a 9.0:1 going to 10.0:1 or 8.0:1.
It seems reasonable to guess that maybe, just maybe, that the reason this engine is known for being so "weak" has more to do with the high compression ratio, which is fine for being NA, but is just a ticking, time bomb for FI. This also explains why some people seem to be lucky and others are not. Perhaps it takes the right conditions to cause a large knock or preignition. Altitude, ambient temperature, quality of the fuel and heat on the motor all influence the possibility of a knock that could be severe enough to bend a rod. Some pump gas is 91 and some is 93. Some might have 10% ethanol, but others might have 15%. There are so many factors, but if the motor is 12.5:1 and FI then the opportunities for some people based on where they live and how they drive could be multiplied. Just saying it is possible.
Regardless, it sounds like I will be fine going with a CARB tune on a stock motor.
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PhyrraM ...I would definitely like to try a ride in a positive displacement SC, and a centrifugal SC, and a turbo car too, but I don't think that is going to happen unless someone local offers me a ride. My intuition says that immediate throttle response is what fits the light, sharp and nimble 86's personality. For a daily, this seems best too. If this car turns into a stripped-down, trailered, track car one day then I would likely change to a turbo.
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new2subaru ...I agree, the Vortech SC is the most OEM looking centrifugal SC, but I still like a more compact setup.
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Xxyion ...I will most likely be buying the SC kit through Racersline. I am a DIYer, but if it comes to it, I have heard nothing but good things about Neal, and I won't be afraid to give him a call.