Got rebuild done & now getting knock at low boost , 5psi.
Only thing changed on new build is ;
- compression up to 9.1 from about 8.2.
- entire new fuel system, from 255l pump & stock lines upgraded to 400 lph pump & -8 lines.
Knock starts rapidly at 5psi , whether at WOT or 1/4 throttle & slowly approaching 5psi in second gear.
Using 91 octane. engine runs well under normal driving. Before rebuild could run 25psi w. alc.
Tune timing is about 27* when KR starts, dropped it down to 17* & still get KR .
XFI Log show no outstanding values.
Actual afr is close to requested 12: 1
EGT looks ok.
wandering if its something mechanical ?
Any ideas ???t
Only thing changed on new build is ;
- compression up to 9.1 from about 8.2.
- entire new fuel system, from 255l pump & stock lines upgraded to 400 lph pump & -8 lines.
Knock starts rapidly at 5psi , whether at WOT or 1/4 throttle & slowly approaching 5psi in second gear.
Using 91 octane. engine runs well under normal driving. Before rebuild could run 25psi w. alc.
Tune timing is about 27* when KR starts, dropped it down to 17* & still get KR .
XFI Log show no outstanding values.
Actual afr is close to requested 12: 1
EGT looks ok.
wandering if its something mechanical ?
Any ideas ???t