Hope I do not get too reamed about this question. Just double checking myself. Running 331ci EFI w/ 76mm Turbo, Big Stuff 3 ECU, MSD Crank Trigger, Mallory Dizzy. I set up the crank trigger per the BS3 instructions 50* BTC then rolled the motor to 20* BTC with pointer on #1 plug and locked down the dizzy. My question: Is 20* BTC a good starting point for the timing? I am not using a cam sensor. Figured this was safe for now till I get to the dyno. I have searched for the answer but have not come up with anything solid. Thanks in advance.

 

Are you planning on running bank to bank? I would run a cam sensor and take advantage of the sequential fueling that this system offers.
Its not a must, just how I've always ran it.
For your question about fazing the rotor at 20 degrees btcd. That is fine, you will be adjusting the timing through the bs3 ecu and your laptop.
Basically the reason the rotor is fazed at 20 degrees is because at full boost this is approximately where your timing will be and where the coil will fire, so the rotor will be pointing right at the cylinder its firing under full load/boost/power/rpm. Obviously 20 degrees of total timing is approximate give or take many factors depending on your setup, but 20 degrees is where it should be locked at. I hope that helps and that I haven't confused you.

 

Thanks a lot for the reply. I know I need to use a can sensor, and I fully intend to do so. I just have not gotten the guts to cut up my dizzy at the moment. That will come in the future. I really just wanted to be sure of my estimate. I know there are variables that will change the adv and retard. I am still learning BS3 as I go as well. I am being extra careful with this car since my last one burned to the ground. Thanks again. Your reply is a big help.

 

When you add the cam sensor it needs to be set at 60 btdc, but that is after you already fazed the rotor at #1 at 20 btdc and locked the distrubutor housing in place.
Basically all you need to do is set it up as so and not worry about it from there, that's the way its setup to work.
Then make all your adjustments sitting on your ass in the car with a computer. Nice and clean, its a beautiful thing when a keyboard becomes your screw drivers and wrenches!

 

Can the BS3 not use the Explorer cam sensor? That seems like a much better option than cutting up a distributor.