Discussion and questions related to the course Reflashing
I just had some questions regarding Cam Timing. I understand that for the lower rpm range you target a more advanced cam angle, and then as the rpm increases you target a more retarded cam angle. This goes right in line with your explanation with air velocity and how you can increase VE by targeting a more retarded cam angle where air can still be forced in even when the piston is rising.
My question is when Road Tuning I'm sure it's impossible to tune the Cam Angle, so would you just leave it at the stock targets? And when you are adjusting the Cam Angle, is 50 degrees the max it will let you go due to Piston to Valve Clearance?
Hey John, unfortunately cam control is one of those areas of tuning where it's very difficult to do a reasonable job on the road. The dyno really is almost an essential here if you want to get worthwhile results.
In all OE engines that incorporate VVT, the cam movement is mechanically limited so that valve to piston contact can't occur. This means you can safely move the cam to each extreme of travel with no risk. In a VVT engine with modified cams it's really important to do this checking manually to ensure no chance of damage if something in the cam control system fails.
Understood, thank you!