4 ms·

yeah, this is actually something we are looking at for the Saab T5 engine series. It uses an integrated coil pack for all the cylinders, which in turn means, a

yeah, this is actually something we are looking at for the Saab T5 engine series. It uses an integrated coil pack for all the cylinders, which in turn means, a failure of one is a failure of all. I know some of the tuners have switched to using more normal coil pack setups, but unfortunately the T5 system is pretty unique so its not a thing that can be easily hot swapped. One interesting tidbit is the coil packs run a bit of current over the plug when it's not sparking to measure ionization to determine engine conditions (i think mostly knock)

bayindirh 5y ago
> It uses an integrated coil pack for all the cylinders, which in turn means, a failure of one is a failure of all. That’s interesting. My coil pack is also integrated, but it’s designed to fail independently. Maybe it’s the design of the coil, but not an inherent shortcoming of the system itself. > One interesting tidbit is the coil packs run a bit of current over the plug when it's not sparking to measure ionization to determine engine conditions (i think mostly knock) Didn’t know that. I knew that engine knock was measured with vibration sensors, crank position relative to other things and engine output measurements via load sensors (irregularity), but ionization measurement is new to me. Have any sources, so I can read more?
- calvinmorrison 5y ago
  I think it was basically since Saab was fairly early to the coil pack game, these "Direct Ignition Cassettes" was in production in 88... Yeah... no standard knock sensor, which is the normal way to do things, but it's much improved because a regular knock sensor on a 900 can't really tell, what cylinder is knocking (and no cylinder behaves the same, regardless of what you do), so on a distributed 900 with the Bosch systems, it'll hold boost back or (with ezk) retard knocking for a few full cycles. With ionization it can determine -which- cylinder is knocking and adjust timing and fuel on that one specifically Here's a good article https://eeuroparts.com/blog/tech-corner-saab-trionic-and-ionization-sensing/ https://eeuroparts.com/blog/tech-corner-saab-trionic-and-ion...
  - bayindirh 5y ago
    That was an awesome read, thank you!

bayindirh 5y ago

> It uses an integrated coil pack for all the cylinders, which in turn means, a failure of one is a failure of all. That’s interesting. My coil pack is also integrated, but it’s designed to fail independently. Maybe it’s the design of the coil, but not an inherent shortcoming of the system itself. > One interesting tidbit is the coil packs run a bit of current over the plug when it's not sparking to measure ionization to determine engine conditions (i think mostly knock) Didn’t know that. I knew that engine knock was measured with vibration sensors, crank position relative to other things and engine output measurements via load sensors (irregularity), but ionization measurement is new to me. Have any sources, so I can read more?

calvinmorrison 5y ago
I think it was basically since Saab was fairly early to the coil pack game, these "Direct Ignition Cassettes" was in production in 88... Yeah... no standard knock sensor, which is the normal way to do things, but it's much improved because a regular knock sensor on a 900 can't really tell, what cylinder is knocking (and no cylinder behaves the same, regardless of what you do), so on a distributed 900 with the Bosch systems, it'll hold boost back or (with ezk) retard knocking for a few full cycles. With ionization it can determine -which- cylinder is knocking and adjust timing and fuel on that one specifically Here's a good article https://eeuroparts.com/blog/tech-corner-saab-trionic-and-ionization-sensing/ https://eeuroparts.com/blog/tech-corner-saab-trionic-and-ion...
- bayindirh 5y ago
  That was an awesome read, thank you!