Retarding base timing for increased boost performance

[Dan-TSS]

I wish this was covered with more in depth detial as it seems to be a common question that I am always pounded with.
I would like to have people chime in with what base timing they set with the distributor for the following(as others stating the obvious, not just me, will back up what I always say). It seems many people have a hard time understanding advance and retard...and get quite retarded(haha) when it comes to thinking it out. :lol:

-'84-'86...original(stock) Base Timing is...20 degrees...retarding the base timing to XX degrees helps with detonation/knock for higher boost with A STOCK ecu.

-'87-'89...original(stock) Base Timing is...10 degrees...retarding the base timing to XX degrees helps with detonation/knock for higher boost with A STOCK ecu.

[bemis]

For my 84T, orginal turbo, injectors, and FP at 48lbs, I put my timing to 15 degress at 10lbs boost. At 15lbs, I use methanol/water injection and return the timing to 20 degrees for auto-x events, ~23 degrees for the street. At 18lbs, with methanol/water injection, I would bring the timing back to about 18 degrees.

Without methanol/water injection, I would follow the pattern, Boost=1/Timing, where Boost is greater than or equal to 6lbs and Timing is less than or equal to 20 degrees. In other words, as Boost goes up Timing goes down.

[Ken in AZ]

Dan-TSS wrote: I wish this was covered with more in depth detial as it seems to be a common question that I am always pounded with.
I would like to have people chime in with what base timing they set with the distributor for the following(as others stating the obvious, not just me, will back up what I always say). It seems many people have a hard time understanding advance and retard...and get quite retarded(haha) when it comes to thinking it out. :lol:

-'84-'86...original(stock) Base Timing is...20 degrees...retarding the base timing to XX degrees helps with detonation/knock for higher boost with A STOCK ecu.

-'87-'89...original(stock) Base Timing is...10 degrees...retarding the base timing to XX degrees helps with detonation/knock for higher boost with A STOCK ecu.

Dan, there are alot of variables to contend with, too much so to make such a blatent statement as to timing versus detonation. Some cars out here in AZ durring the summer have DET problems at stock timing and stock boost. also fuel quality will play a factor, I can only get 91 octane out here, but other areas can get up to 94 octane.

I personally would never run less than 10deg base timing in any stock compression Z31, you would loose too much bottom end and possibly run into an EGT issue. even with my NA compression turbo on 91 pump I would run 15deg base timing up to 18psi on my intercooled set-up.

to summerize I'd say start at 15deg base on any z31, and never go below 10deg base for high boost applications