Mabuhay

Can you folks tell me at what RPM your cams "shift"? I was playing the other day and it seems that the cams shift (sounds like the engine shifts gears) at about 6000 rpms. But doesn't this sound a bit too high especially when the rpm limit is around 7k rpms?

Can X51 owners tell me when their car shifts cams?

knfeparty

Mine is fast at all RPMS.

I do notice a definite difference in sound between 6k and 7k, but I think that has more to do with the intake and exhaust headers than the cam timing.

Mabuhay

At first I thought it that the change in sound was due to my Sport Exhaust. But even when I turned it off, I still get that change in sound at around 6k. But to your post, I don't believe the intake and exhaust headers can dramatically change notes like that by themselves.... I.e. - the cam profile needs to change, no?

balefire

Variocam Plus on cam timing changes at 3200 rpm for all 3.6L whether or not you have x51
https://rennlist.com/forums/996-foru...t-3200rpm.html

However, there is a dip in hp just before 6000 rpm as shown on this x51 dyno plot that may explain the "rush" some x51 owners feel at that rpm.
https://rennlist.com/forums/996-foru...-x51-dyno.html
https://rennlist.com/forums/996-foru...ar-reason.html

I can easily hear and feel the 3200 rpm cam timing change in 2nd gear partial throttle. At full throttle, this disappears.
I cannot hear or feel any difference at 6k. My car pulls strong all the way to my 7200 rpm redline from 3200 rpm.

Attached dyno plots are thanks to oneeyedjack and 10 GT3