more info here: http://www.jacobselectronics.c...r.htm

it's a jacobs boost master timing control. it got 3 *****, one **** is to retard timing of up to 15 degrees(base timing without boost) from stock timing, 2nd **** is to retard timing up to 15 degress on boost on top of what you retard on the 1st ****. it's not a retard per pound of boost. the 3rd **** is the rev limiter, adjustable from 2k - 10k rpm and it work well with my MSD 6A.

since i'm using VAFC hack, i find this device to be helpful. i retarded 4 degrees from the stock timing of 16 degrees and there's no knocking anymore. i retarded 2 more degrees on boost.

i got a question though, how is it that it doesn't need to short the service connector as with the adjusting of static timing found on helms manual? i believe the Apexi ITC doesn't require shorting of the service connector as well unless i'm wrong. any idea about this?

 

from my understanding, you only have to jump the service connector when you are physically moving the distributor. the unit pictured below changes timing by delaying the signal instead.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by keebler65 &raquo;</TD></TR><TR><TD CLASS="quote">from my understanding, you only have to jump the service connector when you are physically moving the distributor. the unit pictured below changes timing by delaying the signal instead.</TD></TR></TABLE>

Thats what I heard too