Variocam engagement abrupt
05-24-2007, 05:26 PM
#47
Race Car
Originally Posted by JimB
Bill, If I'm not mistaken, what people are feeling at 3500 is the valve lift. The timing shift is somewhere between 5800 and 6200. It's what's happening when you see that big dip in your dyno chart.
The timing shift is also binary. If you power the switch, your cam chain tensioner is on one side, if you don't power its on the other.
The timing shift is also binary. If you power the switch, your cam chain tensioner is on one side, if you don't power its on the other.
05-24-2007, 06:29 PM
#48
Addict
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Originally Posted by wrljet
The chain tensioner scheme is for the non-Plus version, no?
1999, it is definitely the cam timing shift that causes the HP drop. If you look at the "before" dyno on the plenum thread you can see it happen. At least in my car the resonance flap didn't have much effect. We unplugged it and it had no impact on the dyno. Go figure.
05-24-2007, 06:51 PM
#49
Race Car
Originally Posted by JimB
Aren't all 3.6Ls Plus? Maybe not. I know the 3.6L we put in my race car still used the tensioner. I know this because we had to modify the cam sensor ring and add an rpm switch to control the timing shift. Once we got it right it worked perfect but it was a pain.
1999, it is definitely the cam timing shift that causes the HP drop. If you look at the "before" dyno on the plenum thread you can see it happen. At least in my car the resonance flap didn't have much effect. We unplugged it and it had no impact on the dyno. Go figure.
1999, it is definitely the cam timing shift that causes the HP drop. If you look at the "before" dyno on the plenum thread you can see it happen. At least in my car the resonance flap didn't have much effect. We unplugged it and it had no impact on the dyno. Go figure.
05-24-2007, 06:56 PM
#50
Originally Posted by JimB
Aren't all 3.6Ls Plus? Maybe not. I know the 3.6L we put in my race car still used the tensioner. I know this because we had to modify the cam sensor ring and add an rpm switch to control the timing shift. Once we got it right it worked perfect but it was a pain.
1999, it is definitely the cam timing shift that causes the HP drop. If you look at the "before" dyno on the plenum thread you can see it happen. At least in my car the resonance flap didn't have much effect. We unplugged it and it had no impact on the dyno. Go figure.
1999, it is definitely the cam timing shift that causes the HP drop. If you look at the "before" dyno on the plenum thread you can see it happen. At least in my car the resonance flap didn't have much effect. We unplugged it and it had no impact on the dyno. Go figure.
Check out the link I posted earlier. It shows the timing adjustment scheme is on the end of the sprockets. Not the sliding tensioners.
Bill
05-24-2007, 10:42 PM
#51
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Originally Posted by wrljet
As far as I understand it, yes, all 3.6s are Plus.
Check out the link I posted earlier. It shows the timing adjustment scheme is on the end of the sprockets. Not the sliding tensioners.
Bill
Check out the link I posted earlier. It shows the timing adjustment scheme is on the end of the sprockets. Not the sliding tensioners.
Bill
05-25-2007, 01:56 AM
#53
Three Wheelin'
Originally Posted by rcg412
That service manual is awesome - thanks for posting!
Freakin sweet piece of literature to go with my 2002 Carrera. Where did you get this?
05-25-2007, 09:12 AM
#54
Originally Posted by jasper
+10!
Freakin sweet piece of literature to go with my 2002 Carrera. Where did you get this?
Freakin sweet piece of literature to go with my 2002 Carrera. Where did you get this?
Bill
05-25-2007, 01:21 PM
#55
Instructor
Join Date: Jan 2007
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I have stayed out of the oil debate but this thread shows a very important part of why I stay with the factory oil specifications. The Variocam plus system is HIGHLY dependent on oil temperature and viscosity.
05-25-2007, 02:06 PM
#56
Race Car
Originally Posted by itorque
I have stayed out of the oil debate but this thread shows a very important part of why I stay with the factory oil specifications. The Variocam plus system is HIGHLY dependent on oil temperature and viscosity.
Every moving part of the engine is HIGHLY dependent on oil temperature and viscosity.
05-27-2007, 03:53 AM
#57
I've always noticed the Variocam kicking in between 2500 and 3000 rpms, but this is with an 02'. Keep in mind that the 99-01 cars have a much simpler system. They only have variable cam degree on the intake only. The 02+ have variable cam degree on the intake and exhaust, in addition variable lift (similar to Honda's VTEC system). Hence why the newer system is call "Variocam Plus". The operation of both systems is completely dependant on engine oil. Even a small deviation from the correct engine oil viscosity can easily cause problems with the engagement of this system.
