Hallo,

i need an advise from someone who has some know-how in tuning a boosted engine.

my setup: Stock B16A1 Engine 10:1 Compression ratio.
Garret T3 with 7-8psi boost.
Standalone ECU.

my AFR is ~14,7:1 until 800mbar (absolute), from 0-3psi i have ~13:1 and from 3psi on until 6psi i have ~12:1
over 6psi i'am a bit rich at the moment AFR is aprox. 10:1 to 11:1.

if i rev over aprox. 5000rpm (Vtec is active) and go over 7psi the car starts bogging.

i think it is no knocking but i have no power at this moment.

ignition is stock with 0,75° per psi retard so i have aprox 18° ignition advance in this area.

Can someone tell me why my car boggs in this conditions and what do i have to do to prevent this?

Thanks
Malte.

 

Tune that 10:1 ratio to 12:1. Too much fuel is causing the bogging.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by MachAF &raquo;</TD></TR><TR><TD CLASS="quote">Tune that 10:1 ratio to 12:1. Too much fuel is causing the bogging.</TD></TR></TABLE>

Ok, i have now 12:1 and its a lot better... but only one problem left.

when vtec kicks in (5000-6000rpm) the car boggs also a littlebit fast after each other, hard to describe. but only in the first 2 gears and ONLY unter full throttle.

what can that be?

same somes up later at aprox: 7000rpm but not always.

Thanks
Malte.

 

Put your timing to 16deg before the retard. Check your gap .025-.028. What spark plug do you use?