Originally Posted by
Longslyde
I've worked with the settings in this area and found that the factory settings are about as good as it gets with a stock cam if that is what you are running. YMMV. The only area that I found some improvement was in the idle/cruise rpm area where GM plays with the cam settings to reduce pumping loss (for economy) and create an EGR effect (for emissions). I had to zero this area out as I was having a problem with low vacuum at cruise and it was causing problems with boost actuation and spark knock. After zero the lower rpm areas, it was much more responsive in that range and manifold vacuum raised by about 4-5 inches, which, in my case, made the supercharger function as intended. I wouldn't mess with the upper end of the tables, I think GM actually had those pretty accurate for the stock cam. Remember, If you change the cam timing in a given range, you have to adjust timing and airflow to find out the benefits or downfalls of that setting.
I do believe there are some substantial gains to be had with an aftermarket cam though if proper tuning procedures are followed. The mistake I see peple making is that they are only changing the setting for cam position and not adjusting the other parameters that go with that. In which case, it will not perform well or as well as it could. I believe this exact scenario is what makes people take the VVT out of the engine thinking that a non-VVT engine performs better.
Tak care! :cheers: