I've only owned my Tubo Trans Am for 4 months and have quite a bit to learn. I have experience with small block Chevys, carbs and HEI but never had to graduate to EFI and distributorless ignitions. In an offline thread I was learning some things about the TTA ignition system. I learned that the module under the coil pack is just basically a big honker version of the transistor amplifier/switch as found in an HEI. The ECM controls both the timing of the injectors and ignition.
It's my understanding that if one is using a stock ECM (or one with an aftermarket chip), they can just forget about base timing and advance curves - trust whatever the programming is - after the cam and crank sensors are set.
But my car has an Accel Gen 7 DFI. The spark advance across the entire range of the engine (MAP/load vs. RPM) is programmable. So, question number one is: where can I find basic/typical advance curve information for the 3.8 turbo engine that I can program into the ignition screen?
This Gen 7 system can be used on almost any engine of course. The main screen looks like a dyno display. It includes a real-time timing readout. In the installation instructions for the Gen 7, they tell you to compare (and adjust) the reading on this screen to match a (true) timing light reading off of the balancer. On the 3.8, no timing mark (that I've seen) and no timing tab present. So... I'm kinda stuck when trying to do this. Aside from tearing the engine down, adding a timing tab, degreeing the dampener and setting #1 at TDC, is there something else I could do?
Fortunately the car runs, so maybe I don't need to verify the base timing. But one of the reasons that I bought this car is to expand my knowledge of automotive technology (EFI, distributorless ignitions and turbocharging) - and occasionally take the car to the track to validate improvements. So I am trying to learn as much about the car (theory and practice) as possible.
Best, BC3
It's my understanding that if one is using a stock ECM (or one with an aftermarket chip), they can just forget about base timing and advance curves - trust whatever the programming is - after the cam and crank sensors are set.
But my car has an Accel Gen 7 DFI. The spark advance across the entire range of the engine (MAP/load vs. RPM) is programmable. So, question number one is: where can I find basic/typical advance curve information for the 3.8 turbo engine that I can program into the ignition screen?
This Gen 7 system can be used on almost any engine of course. The main screen looks like a dyno display. It includes a real-time timing readout. In the installation instructions for the Gen 7, they tell you to compare (and adjust) the reading on this screen to match a (true) timing light reading off of the balancer. On the 3.8, no timing mark (that I've seen) and no timing tab present. So... I'm kinda stuck when trying to do this. Aside from tearing the engine down, adding a timing tab, degreeing the dampener and setting #1 at TDC, is there something else I could do?
Fortunately the car runs, so maybe I don't need to verify the base timing. But one of the reasons that I bought this car is to expand my knowledge of automotive technology (EFI, distributorless ignitions and turbocharging) - and occasionally take the car to the track to validate improvements. So I am trying to learn as much about the car (theory and practice) as possible.
Best, BC3
