Good thread idea sikdatto1200,
Here`s some thing to check and some remedies,
-ENGINE CONDITION, piston damage, ring wear, poor oil control .(will cause mixture contamination and lower octane rating)

-BLOCK PRESURE, water pump must be making fairly good block presure (about 25lb)
never run an engine without a thermostat or suitable restrictor to maintain good block pressure. otherwise you will be getting localised boiling (Hot spots) around exhaust valves and combustion chambers leading to higher combustion temps and detonation. Even tho the temp guage is reading normal!!!

-INTAKE AIR TEMP. This is probably the the most important one for turbo engines. I cant recall the exact figures but something like for every rise of ten degrees c in air intake the fuel octane requirement goes up by one point..(feel free to correct my figures here) Realising that a turbo compressor at at 65% eff. making 20lb boost on a 20 deg. day has a discharge temp of 120degrees!! This is where intercooling comes in!!
Draw through carb setups are the most handycapped here.. Increase the fuel octane or a very good water injection set up might get these setups out of strife unless you lower the compression, which can give you a sluggish engine off boost.

-OTHER CONTRIBUTING FACTORS, mixture quality, the shape of the combustion space(plent of squish).Igntion curve and total advance, plugs, the cars gearing, engine size v car weight ..

Or something like that,
Simon.