Can somebody help me understand the TDC offset angle?

the Haltech series 6-8 FD map has this set to 5 degrees, does it need to be adjusted with a stock trigger setup?

is this only for people using aftermarket trigger setups?

Thanks, i'm still learning since switching over from Microtech

 

Just use the haltech default settings. Lock it and check with a timing light

 

using the default settings on the S6 map which are firing at -5 with a 15 split on lock mode, and with a 5deg TDC offset angle, im hitting the factory 20deg ATDC mark on the front trailing coil. then when moving the timing light to the leading coil, im hitting the 0 degree mark my engine builder made on my pulley.

does this sound correct? my logic tells me that with those settings it should really be hitting -5 deg ATDC on the leading and not 0

 

just confirming that everyone with the stock FD trigger/pulley are using -5 as a the TDC offset? and the 15 split -5 lock timing to check.