DonRaye,
I think you are about there with 10.5:1. 11:1 might be pushing the envelope. There is a early detection / prevention tool that not only detects the detonation but corrects for it in real time. If you don't use electronic engine management then it pulls spark from all cylinders simultaneously
The engineering side is just one step short of black magic but the performance is stunning. It uses all its wizardliness (is there such a word?) with electronic engine management. Without electronic engine management I understand the function is similar but it affects all cylinders the same. Basically what happens is when it first hears the sonic signature associated with detonation it pulls several degrees of timing (you can set the number). If the knock is detected on the next turn of the crank it pulls more timing. As soon as it hears no further knocking it begins to add timing until it detects detonation again. When it finds this point it backs off the timing just enough to prevent detonation and holds the mark until bad things happen again.
The website is click here =>
http://www.jandssafeguard.com/MarineRacing.html
Great insurance for the time you run low on fuel and the only thing available for the next 40 miles is a Farm Tractor fueling depot with 89 octane.
Ed (another old fart)
p.s. I may have miss-spoken at the beginning of this post. You ought to give John a call. As I was reading his page for the marine/racing unit it may not require an electronic engine management system to adjust timing on cylinder by cylinder basis. He is easy to talk to and will give you the straight story right out of the box.
This is the unit for individual coil direct ignition engines. It has more explanation, a testimonial link at the top of the page and some explanation of the theory of operation. Click here =>
http://www.jandssafeguard.com/Vampir...S_Vampire.html