Subaru Impreza GC8 EJ20 Trigger calibration base timing

[Christoforos]

Hi!

I have difficulty to understand how to setup the trigger calibration base timing because of the timing light. I am using digital timing light Sykes-Pickavant No.300530. Attached you can see its user manual.

Below you can see a picture of my timing pulley at idle and I drew and arrow to show you where it goes at 3500rpm. The second picture shows a preset value of degrees on the timing light as per the manual. I highlighted that below and also another point I got confused.

 

For now I did not make any changes on the base timing. Please see below.

 

Can you please help me understand who this really works and what value should I set my base timing?

 

Thank you so much!

 

 

 

300530+Digital+Timing+Light.pdf

[Adamw]

Set the lamp so zero advance is showing on the back LCD.  

In the "Set base timing" screen, set the "lock timing to" 10 degs.  With the engine running the mark on your pulley should line up with the 10deg mark on your front cover.  If it doesnot line up then adjust the trigger offset until it does (note you have to hit the enter key after changing offset).  

[Christoforos]

Hi Adam,

Thanks for the instant reply. When I changed the lamp to 0 then it just shifted 10 degrees and instead of showing near  0 as the picture above (white mark) it was shifted near 10 degrees at Idle and then much further at 3500. So I left the lamp setting to 10 as the default setting.

It seem to me though that the timing was shifting to 24 degrees when I was releasing the trigger of the lamp to go to 3500 RPM and then press it again to see the timing. I saw that if I kept it pressed from Idle and then increase the RPM then the timing was not changing by a lot and it was around 0. So I guess this was the correct procedure. Thus I added another 2,5 degrees and 60ms to delay and now the timing is spot on at 0 at the entire range of RPM!

To summarize, it was actually a wrong procedure of the use of the timing light.