To VVT or not to VVT

[kerrige]

Ditch the vvt if you switch cams but I would keep the cam you have and therefore keep the vvt. Did you swap up gears yet? That cam is also begging to be sprayed.

[Crazy Blu]

Ditch the vvt if you switch cams but I would keep the cam you have and therefore keep the vvt. Did you swap up gears yet? That cam is also begging to be sprayed.

Couldnt agree more!!!
SHIFT

[Gus]

I have not done the gears yet. I drive a ton of highway driving so I have been putting it off. I'm looking at the 210 / 224 vvt cam that comp is offering. Moves everything lower but there is not a hole lot of info on it. I talk to comp and they can do any of their cams even the 212/218 on a vvt core.... If I take back back the front and rear gears I can get the new cam and nitrous for a even exchange...

[Gus]

Just to give you an idea how much lag there is. We had a fresh rain here today and it would not spin after trying several times. It is a VVT cam and I dont think its to big but I think its actually the "early style" core which would put it 14 degrees retard on centerline the entire RPM range. There was no way to know so it was a trial and error type of deal. I think if I get the right grind in there the truck will haul... that comp vvt cam I was looking at 210/224 I think has a good duration for having some low grunt to it. I even considered the 208/212 custom ground with a 112 lsa vs he 115 to give it the "sound" of my current cam.

[kerrige]

Another issue to keep in mind is that the 4.8 will never have gobs of torque. It needs the gears to be truly happy. It is one of the very best mods out there! A different cam isn't going to make the huge difference you are looking for. Either ditch the VVT or keep the cam. VVT sucks!!!!

[Gus]

I under stand that but the stock cam had WAY more power at the bottom end and only slightly less top end then the current cam. A lot of the stuff I have been looking into lately leads me to beleive that the cam is not on the right core. Some of the first VVT cam people had these exact same issues that I am having.... On vvt cam should be advanced in the low RPM and retarded in the top RPM and since I am thinking its 14 degrees behind all the time bottom end is HORRIBLE and top end is even more retarded then needed i must have the wrong core. No big deal since it would make a good cam for someone with the first style of vvt if i can sell it. The other cam I have been looking at is a 215/223 on the LSR lobes which is listed as HYDRAULIC ROLLER-Very strong torque and excellent response. Works best in heavy vehicles, low rpm applications. LSR™ Cathedral Port (Small Displacement or Max Torque, 4.8L-5.3L) and put this on the correct VVT core or do the conversion to Non VVT. I would have to yank my LS6 springs out due to the much higher lift but due to the low low miles on both cam and springs maybe I can hook someone else up with the 08-09 VVT engine.

[Gus]

Sorry for all the posts but the beer is full effect and it looks like there isnt enough range to make it happen on the advance side to see if my theory is correct.

Article from Hotrod MagThe Gen IV's VVT system is very flexible and allows advancing the cam 7 degrees and retarding it 45 degrees for a total of 52 degrees of latitude.

Tech note from Comp cams VVT tech bulletin. The difference in the pin between 156 and 189 cores equates to 13 degrees cam retard (if a 156 is used
where a 189 is required). {thinking i have a 156 "type" core installed and with only 7 degrees of advance available in the phaser I am not going to be able to make up the 13 degree difference... Looks like I won't need to call Allen..