still knockin'

[1 RARE T]

well my lmtd. is still giving intermitten knock (.9-7deg.) when ever it decides to. put in some octane boost that CLAIMED a 4-6 point increase. B.S. raised fuel pressure back to 50 psi line off. now car feels slower and sometimes knocks at 30mph and sometimes at 90 mph. 02' s are usually above 825 sometimes 870 and still knocks! how can it retard 3-4 degs with those 02's ?

 

[John Larkin]

17psi on 93 octane can easily knock. Octane boost is worthless. You need xylene or something stronger. Your other knock source is too much fuel pressure. Back it down to around 43 line off, back off boost to 15 and see how it goes. Pull a sparkplug after WOT and look at the coloring.