what are the advantages to running a 0 timing split on the ignition ???

 

There is a sticky about this in the single turbo section.

-Destin

 

In theory better torque at higher RPMs, BDC used a 6* split on my car with 17* leading advance on 111 octane. At 25 psi we made 506rwhp/387tq (yesterday ) on essentially a small street port/stock 2mm seals/PT67 .81 P trim. Basicly for most guys it's not worth the risk of firing the trail before the lead, so they make it skinny, but not zero.

 

Not sure if you realized what you said there in the last sentence, but negative split (trailing firing before leading) should never be used under boost, ONLY under vacuum. I know CLR specified that I must have split under boost. I'm currently around 8 degrees split with MUCH tuning left to do.

 

I think Carl was saying that when you run 0 split, there is a chance that your trailing will fire before leading. As you said, this is a HUGE no-no under boost. He's not advocating negative split, he's saying that you should watch out for it when running 0 split.

 

Right, it the OTHER thread () there's mention of some ECUs not being able to handle the timing that accurately, so if you run 0 split, you run the risk of occasionally hitting negative split=bad. To what degree, I don't know. I'm at 5 right now and will probably bring it to 2 to see what happens.

It's a better idea to run larger split at low load/idle though to help smooth things out.

 

If using a PFC for a FD, an easy way is:
(1) you set up you timing only for IGT, you can also set IGL the same as IGT just for your own reference.
(2) run two leading coils with each having it's own ignition amp to fire both plugs for it's rotor, and fire the coils from the IGT leads.

This insures 0 split.

If you want to run 4 coils and amps, then split each trailing lead into two leads.