No vacuum at idle on cammed LT4

[JASON11WS6]

Just got our shop car Z06 running again. It's cammed with a 2650 on it. Didn't have an issue with the idle like this before but the vacuum is almost non existent. It surges a bit and if I put it in gear sometimes it'll pop and the timing goes negative. We did a smoke test and there is no vacuum leak causing this. I started to play with the virtual torque tables and the final torque readings are in check (20s). I was going start messing with the VVE as well but my laptop just took a dump.

So what I'm asking I guess is will playing with the VVT and VVE bring my vacuum numbers back down? Or is this a physical issue I need to mess with or in the tune?

[Ben Charles]

Mechanical

[JASON11WS6]

That's what I was really thinking but the car does not have a vacuum leak. It's a massive cam so there isn't much vacuum to begin with. What could cause a vacuum lose like this without a leak? Maybe I take my catch can off the manifold/blower and put it on the intake tube?

[Ben Charles]

What are you doing with the PCV routing from the bottom of the blower?

I assume it’s hitting on all 8 cylinders?? Naturally a miss can cause vac issues…

How big is the cam and what is the KPA reading!?

Log atleast could help possible

[JASON11WS6]

It's running like 70kpa in park. When I put it in drive it'll go up to 80 and spike up to 90 at times when it's cold. The cam is big BTR max effort pds cam. In the past the car still idled and the timing bounced around giving it an amazing chop.
I wonder if it has something to do with the pcv routing. Right now I have a MM catch can coming off the drivers valve cover. The bottom of the blower is plugged off I believe as Mighty Mouse recommend. The passenger side valve cover is vented to the dry sump line and their is another line that goes from the dry sump to the intake tube. I'll check over all that stuff first. No logs until i get my laptop back up and running.

[Ben Charles]

That cam needs a tq converter period…

[EliteTunedSchool]

Can you put a log up. What is the Grams/Cyl at?