+1
Best torque generally occurs when peak cylinder pressures are reached roughly 15 degrees after top dead center. As long as you can advance your timing enough to have peak cylinder pressures at the right time you are good. Turbo set ups, especially high boost applications are nearly always knock limited due to extremely high cylinder pressures. This is why you see large hp gains from W/M injection and high octane fuels because they allow timing to be advanced to the point where peak cylinder pressur occurs at the right moment (roughly 15deg atdc instead of for example 25deg atdc knock limited). If you are not having detonation/knock before your torque curve peaks, then 94 isn't needed.
I'm not trying to repeat Captain Bondo, just reinforce.
Cheers.
Quote:
Originally Posted by Captain Bondo
What it actually depends on is whether or not you are knock limited currently with 91. Many small-bore normally aspirated engines with pent-roof combustion chambers are not knock limited on 91.
In other words, ignition can be advanced to the point that makes best torque, and further advance results in power actually dropping off. If you can hit that point currently then you will not gain anything.
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