If you hook your distributors vacumn advance to a constant vacumn source (ie not manifold vacumn), then you will have way too much advance at WOT. In the same way if you advance your timing to say, have 8 degrees mechanical advance at 1000, then by 1500 RPM a full 22 degrees advance, your car will knock hard down at low rpms (to much vacumn advance). I have my vacumn advance hooked up to a manifold vacumn port, ie no vacumn advance at WOT.
The way I set my timing was like this: i bought a weight kit, with weights and springs for 22 degrees advance at WOT. the advance curve I used is like this:
base advance: 8 degrees
mechanical advance:
8 degrees at 1000 RPM
15 degrees at 1200 RPM
22 degrees at 1500 RPM
the rest is vacumn advance. I created my own lockout tab to stop the vacumn advance from going above 15 degrees.
So at idle I have: 8 base + 15 vacumn = 27 total
At WOT I have: 8 base + 22 mechanical = 30 total
I find I have to use 94 octane gas with this combo to not knock at lower RPMs. But that might be just because I have oil in my gas! XD
This ignition combo really woke up the car over stock.
The way I set my timing was like this: i bought a weight kit, with weights and springs for 22 degrees advance at WOT. the advance curve I used is like this:
base advance: 8 degrees
mechanical advance:
8 degrees at 1000 RPM
15 degrees at 1200 RPM
22 degrees at 1500 RPM
the rest is vacumn advance. I created my own lockout tab to stop the vacumn advance from going above 15 degrees.
So at idle I have: 8 base + 15 vacumn = 27 total
At WOT I have: 8 base + 22 mechanical = 30 total
I find I have to use 94 octane gas with this combo to not knock at lower RPMs. But that might be just because I have oil in my gas! XD
This ignition combo really woke up the car over stock.
