Ignition Mods

With the factory PCM options are a bit limited in what can be done for ignition system improvements. Switching to an aftermarket ECU opens up the doors to almost anything you could ever want to do, but this page is just about what can be done using the factory PCM.

The 3800 uses a waste spark ignition system where two cylinders each share one coil. Because of this your coil options are a bit limited unless you want to perform surgery on your ignition control module.

The factory ignition system is actually very reliable and quite good for higher horsepower builds according to most people. Typically though spark plug gaps will need to be tightend pretty significantly once you use a turbocharger. Most will gap the plugs down to around 0.025“ instead of the factory 0.060”.

You will know if you need to decrease your plug gap if you start misfiring under boost and everything else looks okay. It's a pretty common issue.

You can switch to aftermarket coils to improve the spark of the factory ignition system.

The L67 and L32 engines are equipped with hotter coils than the L36 or L26 engines. These can be used to improve the performance of the factory ignition as well.

L67 and L32 coils can be identified by the blue tab located on the bottom of the coils.

Way above what I want to try to explain right now, but basically it's running 2 ICMs in parrallel to output more power to the coils.


There is one aftermarket ignition controller that is well-known. This is the MSD 62152 DIS-4 Ignition Controller.
This replaces the factory ICM and will also require an adapter to mount and use the factory coils. This allows you to use a 2-step launch control.

Amazon reviews of this have been pretty mixed though and it is pretty expensive with a price tag of $700 for the box alone.

You would need the MSD 8870 coil interface module for all 3 coils as well and that could be an extra $150.

There is a device called the “N2MB WOT Box” that will allow you to set up a 2-step launch control and no-lift shifting. It basically cuts power to the ignition control module to kill spark at a set rpm or during shifts.
You can find these from most vendors and will cost around $200

To make this work with the ICM in these cars you will need modify the ICM and separate the coil power from the power leading to the rest of the module. The ICM module itself needs to have power all of the time while the car is running, you can't pulse power to it or you will see all sorts of crazy ignition behaviour.

Some homework will need to be done when you dissect your ICM and determine which pin receives 12v. You could do this with a multimeter and probe the leads that lead down into the chips themselves or if your ICM looks like this one you could just do the same thing that was done here.

The 12v power wire is shown as red in this image. The idea is to provide separate power sources to the coils and the ICM circuits so you can pulse or cut power to the coils while the rest of the ICM still has 12v:



Seal it back up with waterproof RTV or something and make sure the new wire always has 12v with the ignition in “run” and “start”. Then feed the old wire power from the WOT box