At what point should I mess with the timing or fuel pressure on my
Lo3 305 TBI




TBI Rules

when it works :lala:

 

Spend $20, get Summits 0-30psi FP gauge, $10 for the Mr.Gasket t-fitting, and splice it into the top flex fuel line. Record what the FP is when the underhood temp is cool. Make your FPR adjustable (I've attached a pdf file explaining how).
Use a timing light and record your base timing. Advance it a couple degrees when you get to the track and after you get a few base line runs. Look at MPH, if you gain mph, bump up a couple more degrees until you loose mph, then back off a couple degrees. THEN adjust your fuel pressure. Play with it until you notice no difference in mph, then go back to timing.
This is the basic way to tune until you get into vacuum AFPRs and eprom burning.