Exactly, it's pretty much always the tune, or lack of. I'm running 8.5 PSI (almost 9 PSI when temps are in the sub zero's) but have no issues after a few thousand miles of hammering. I'm running 580 RWHP (dialed way down).
So, the major differences I have seen in the Jeep world, is that many who install blowers use a canned tune, or a tune and datalogger for remote tuning.
In most other cases I see with performance tuning, I see guys putting their cars on Dyno's during the build and tuning, with very extensive tuning taking place. That's something I don't believe you can achieve to the same degree of precision with just datalogging and remote tuning. I also notice that many of these blown engines are using tunes by the same "tuners".
The guys I use for tuning have a lot of experience building and tuning SRT's of both generations. The tuner there had explained what the issues are in the 6.4's and what to avoid during tuning, which is timing. When we tuned, on the Dyno and in the streets, he left a lot of timing and leaning out of the tune, to run much safer. So, I'm not fully optimized on AFR or timing, and we figure there's about 50-70 HP left in there, if I want to go ahead and forge internals, namely pistons.
Eventually, I'll do that and unleash the rest of what's there at 8.5 PSI.
That said, the Centri blower should still be kicking ass, but at 5 PSI, it won't blow your socks off. If you have a good local tuner who knows these builds, get a smaller pulley and belt and let them tune at @ 8.5 PSI. That will make a huge difference.
I run one of my cars with 18.5 PSI on a Vortech YSI blower, making 1050 RWHP and it belts out a hell of a lot of power. I can't even put it down because I never built the drivetrain, so I'm running Nitto's that just spin at part throttle in any gear at any speed. LOL
Your issue isn't the BOV or the blower; it's the tune and low boost you're making, that's all. Get a good tuner who's done these trucks and let them make the changes you need. You'll never look back.
@ Fairbird...either one will net you pretty much the same overall power and speed in this case. RIPP isn't Whipple. The two are just very different in the way they deliver the power. But if each were to optimally tune @ 8.5 PSI, you'd probably see pretty much the same power from each. One makes more TQ at low speed and the other makes it high speed. One uses a BOV, the other doesn't. One looks factory installed, the other doesn't. Etc..etc....etc....
RIPP doesn't build a thing...they just assemble kits and maybe bend some tubing. Vortech blowers are available to anyone. They use the Vortech V3 SI trim blower, good for about 700 RWHP in a solid build. All RIPP does is either fabricate the bracket, or have it done by a machine shop and they ONLY do a few Dodge / Jeep vehicles, nothing else. They are a small garage style kit builder. They don't build the blower, the BOV, the intercooler, the pulleys, etc...
Most of the blown 6.4's I've heard about are equipped with RIPP kits and RIPP base tunes....
Whipple is a whole other story...
YMMV