Originally Posted by E3r2E9r
Correct me if I'm wrong but that is a separate unit that needs to be purchased? What percentage of people actually use it? I never here much talk about it. How does one know how much ignition to reduce? CPS module is great but someone would still need to tune it and I doubt many go through the motions to accurately dial it in. I've done some research but I dont hear many people tweaking their CPS modules, correct me if I'm wrong, I'm willing to listen.
It's an add on for the G4 and native on the G5. There is a default curve programmed mapped on boost, RPM, IAT, and gear. To throw out data points at say 15psi 5500rpm its around 3.5 degrees in 3rd, 4degrees in 4th, and 4.75 degrees in 5th. Normally users just run the default mapping with it but it's also user adjustable.
BMS has always been clear that the benefits with CPS are minimal on pump gas and nonexistent with meth but many come from other platforms like Subus where it's absolutely necessary. The concept of a truly superb adaptive ignition system and what BMW has done with it are foreign to them. So it's easier to just let those customers run the CPS module so they can feel warm and fuzzy. Normally it's only suggested for those with large turbos or nitrous, those running exceptionally poor fuel quality, or those who want to run a boost profile that dramatically differs in shape from the OEM profile.