6.4 Afternarket Cam VVT Tuning

[FLandy]

Yes, with a degree wheel and dial indicater. The card that comes with the cam will have on it somewhere "installed intake centerline" or something like that. You're basicly checking to see if you got everything lined up correctly when you installed the timing set. Search for "checking camshaft centerline" on Youtube.

[LilSick]

The cams that are to be installed 'locked' have the dowel in a completely different location than the cams that are to be installed 'limited'

you dont by any chance have a motor on the stand right now do you FLandy

[LilSick]

I tried lowering the numbers in the high rpm to gain more hp but i feel the car power drop. Doesnt make sense. Normally retarding the cam should gain hp up top.

like i just said ^^^ that would depend on where the dowel is

if the cam is meant to be locked, not limited, it is already retarded a bunch

[Spray-Cam Hell-Ram]

Well, I for one, am starting to realize that you likely do have to check your centerlines by way of a wheel and an indicator, because I am also starting to think that these centerline values in at least some folk's logs may very well be bogus values for some reason. I'm over here scratching my head a bit because my intake centerline does not match what my cam card specifies. What's got me confused here is that according to my logged centerline and I'm not talking about a degree or two here. I have it figured to be a 9-degree variance between the two... but that being said, I just don't see how this could be right. If this were the case, wouldn't a 9-degree difference in cam position, to say the least, have a negative impact on this build's performance?

[LilSick]

wouldn't a 9-degree difference in cam position, to say the least, have a negative impact on this build's performance?

in many areas of the power curve, yes

the camshaft is the brain of a naturally aspirated reciprocating engine

[Spray-Cam Hell-Ram]

Exactly. I figured that would be the case as well. Which now makes me fairly certain that these cam positions that our pcms are showing through our scanner logs are likely bogus for whatever reason. Being phaser locked, it never made much sense to me why my exhaust cam position was at 128 to begin with. That would mean that my intake cam centerline is sitting at 102. The closest 5.7L cam grind that I am aware of to having an intake cam centerline that's within even 5-10 degrees of 102 is a Comp Cam with 6 degrees advance ground in and a centerline of 108 I believe.

[LilSick]

the main thing until this gets sorted is the 9 degree 6.4 vs 5.7 thing

[Hemituna]

The PCM will only ever show the stock cam CL numbers.
The PCM does not know you have changed the cam.
If it is now fixed (not limited), it will stay at the max advance or lock-pin number.
This is 128 on 5.7's and 134 on 6.2's, 6.4's.
You need to translate this number to suit your cam.
If your new cam is 113LSA +3, this means that at lock-pin (full advance) the intake CL will be 110 (113-3) and
the exhaust 116 (113+3)....The PCM will still show 128 or 134 tho....

[LilSick]

The PCM will still show 128 or 134 tho....

You need to translate this number to suit your cam.

Oh yeah, 6 degrees. Not 9. Why are rick n them saying 9?

Translate it? Where is the cam position sensor reading from anyways?