Timing

[ynot]

Usually retarding the timing helps with turbo spool, itll affect upper boost a but not much though.

Advancing or retarding is just changing where your heat energy is used with retard the combustion gas dont hang around the cylinder as long an are pushed into the exhaust an the extra heat spools the turbo quicker leading too better power an higher egt's. With advancing the combustion happens sooner an the gas's stay in the cylinder longer giving a more complete burn for better mpg, but the heat energy from that better burn, instead of going out the exhaust for the turbo gets absorbed into the motor making for higher coolant/oil temps an lower egt's

Hope that makes sense