Rotor Phasing a Pro Mag 44 with a Pro Cap

Alright well im trying to get this right but have been told multiple ways of doing this and multi point at which I should be checking my rotor phasing. I was hoping someone can set me straight.

I have Twin Turbo BBC with a pro mag and bs3 engine managment efi system. I have my base timing set at 25 with the ecu disconnected so the is the pyshical fixed timing. I plug in ecu and comand 32 and check it with a light and its right on, I pyshically locked the mag a 25 because I will not run more than say 22 deg or so under max load/boost. I have read and been told to divide max retard by 2 then set phasing at that point so say 12.5. I however pull 27 deg out on the starting ling to build boost/anti lag this is 20 deg off of pyshical 27 off of base 32 which is 7 deg electronically advanced to really only 20 back. I do not know where to set rotor phase.

Any advice would really be appreciated. Thanks in Advance!!

 

First let me state that I am no turbo expert by any means, but here is what I see.

On an engine that only sees retard from base timing the common practice is to split the difference between the base timing and the retard timing so if you had a base timing of 35 degrees and a max retard of 15 ( yielding 20 degrees ) you would split the difference 7.5 degrees and set your rotor phase at 27.5 degrees.

On your engine you will probably have two or three possible trains of thought, my choice would be #1

1 Since your engine runs anywhere between 7 and 32 degrees you should split it at and set at 19.5.

2 Since it runs under heavy load between 7 and 22 degrees you should split that and set at 14.5

3 Since you sometimes run as much as 32 but most of the time during the run its 7-22 you should split that difference and set it at 17


The good news is that I know people who pull 14.5 with a small cap where there is no ability to phase the rotor and it works without missfire so even though you are pulling 25 total you have the ability to phase and split the difference so you are really only 12.5 out at the crank which is 6.25 at the rotor.

When you said that you were going to phase at the 12.5 I think you meant to say you were going to phase with 12.5 out of your 32 and set at 19.5 either that or I am misunderstanding this whole rotor phasing deal and need an education, wouldn't be the first time.

R/G