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NoDOHC · 04-02-2011, 07:11 PM

TTL means Transistor - Transistor Logic. This is almost always referring to a 5V signal.

There is no reason that I can think of that you should power your coils all the time (feed the Battery + with a switched source). The secondary ground should be connected as close to the spark plug as possible (this is the return path for the spark), the battery ground should be connected to a good ground point or the battery negative

Will the Platinum Sport ECU permit driving a coil at 5VDC instead of 12? (adjusting the pullup to 5V instead of 12V)? If so, you can invert the ignition output, drive the high at 5V and connect the low to the ignition output.

You can also ground the negative side and leave the output non-inverted (it will go high to energize the coil, fall to fire).

There are basically 2 things that you need to know. First, are the TTL inputs capable of accepting 12V (nominal - actually about 14V)? If not and second, can your ECU drive to 5V instead of 12V?

04-02-2011, 07:11 PM	#2
NoDOHC The quest for more torque Join Date: Sep 2008 Location: Sheboygan, Wisconsin Posts: 855 Rep Power: 17	TTL means Transistor - Transistor Logic. This is almost always referring to a 5V signal. There is no reason that I can think of that you should power your coils all the time (feed the Battery + with a switched source). The secondary ground should be connected as close to the spark plug as possible (this is the return path for the spark), the battery ground should be connected to a good ground point or the battery negative Will the Platinum Sport ECU permit driving a coil at 5VDC instead of 12? (adjusting the pullup to 5V instead of 12V)? If so, you can invert the ignition output, drive the high at 5V and connect the low to the ignition output. You can also ground the negative side and leave the output non-inverted (it will go high to energize the coil, fall to fire). There are basically 2 things that you need to know. First, are the TTL inputs capable of accepting 12V (nominal - actually about 14V)? If not and second, can your ECU drive to 5V instead of 12V? __________________ 1986 GXL ('87 4-port NA - Haltech E8, LS2 Coils. Defined Autoworks Headers, Dual 2.5" Exhaust (Dual Superflow, dBX mufflers) 1991 Coupe (KYB AGX Shocks, Eibach lowering springs, RB exhaust, Stock and Automatic)