I tend to agree with both of the above comments in general.
@RustyRatRod i will say this, don’t think of it as pulling timing out, think of it as needing a new optimal timing number. As the air in the chamber is now much more dense, the optimal timing number will drop from an optimal NA number. NA an engine might like 34-35 degrees for wot. That same engine on boost might make the best power on 28-30 degrees. For example;
My 489 BBC on the dyno NA made best power at 39 degrees. Same engine only with turbos made best power at 30 degrees at 9psi. We swung the timing all over and were NOT octane limited. We ran 118 octane for initial testing. The new dense fuel mixture “required” a new timing number.
One more point, dropping compression on a boosted engine has the exact same effect as dropping the compression on an NA engine. Boost is a multiplier.
