Changing Timing Reference Angle after initial setup?

[zeppelin264]

Can you change the "Reference Timing Angle" after you set it up to 50° BTDC? I'm thinking you could go in, set RTA to 60° in the menus and then lock your timing to 15°, resync the distributor and now you've effectively changed the RTA from 50 to 60? Does that make any sense?

[Danny Cabral]

Can you change the "Reference Timing Angle" after you set it up to 50° BTDC?

You can change the Ignition Reference Angle, but you'll have to synchronize the distributor again. If you have a Holley Dual Sync distributor, it has an inherent Ignition Reference Angle of 50°.

[rel3rd]

Danny, what does that mean for someone like me, who runs 50° cruise timing? Would I still set the Reference Angle at 60°?

[zeppelin264]

The reason for the 10° difference, is so that the computer has time to calculate where it needs to land the timing. In theory it should only take 1°-3° worth of time to calculate this. So if it's working then I doubt you'll have any issues, but according to Holley, you should have a reference angle of 60°.

[Danny Cabral]

Danny, what does that mean for someone like me, who runs 50° cruise timing? Would I still set the Reference Angle at 60°?

https://forums.holley.com/showthread...8860#post88860 (Related Forum Post - Ignition Reference Angle)

[rel3rd]

Danny, what does that mean for someone like me, who runs 50° cruise timing? Would I still set the Reference Angle at 60°?

The reason for the 10° difference, is so that the computer has time to calculate where it needs to land the timing. In theory it should only take 1°-3° worth of time to calculate this. So if it's working then I doubt you'll have any issues, but according to Holley, you should have a reference angle of 60°.

https://forums.holley.com/showthread...8860#post88860 (Related Forum Post)

I should have specified. I do run 60° Ignition Reference Angle (50° cruise timing) right now, with an MSD distributor.
Danny mentioned the Dual Sync & 50°, and I was just curious if the same rules applied. I believe they do, just wanted to be sure.

[Danny Cabral]

Yes, the same Ignition Reference Angle rules apply, but not necessarily 50°. EFI distributors have an inherent Ignition Reference Angle built-in, and if you change it, the rotor-phasing will be off. I once made this mistake with my old Mallory Hall-Effect EFI billet distributor (which I converted to my cam sync unit - LINK). I was wondering why I had to replace the cap & rotor so often (burnt terminals).

Testing the MSD CD ignition box. Points Output - white wire & Magnetic Pickup - violet/green triggering: https://www.msdperformance.com/suppo...ng_techniques/ (Troubleshooting Info) I would also ensure the distributor's "rotor phasing" is correct: http://documents.msdperformance.com/8644_tb.pdf (MSD Rotor Phasing Document) MSD has a good video on why it's important: http://www.youtube.com/watch?v=aWMlNwGW0tM (MSD Tech - Rotor Phasing Video) For naturally aspirated engines, the rotor is usually phased halfway between minimum & maximum amount of timing advance used. For forced induction engines, the rotor is usually phased at maximum boost retard, because that's when cylinder pressure is the greatest.