How to tell if your Whipple belt is slipping

So I went down to a 3.5 pulley with 93 + Octanium. I'm seeing less boost on my boost gauge now by around 1 psi. I know that isn't necessary the best indicator. I'm curious what gear or rpm you are most likely to see belt slip with the 6rib. It's not something I have experience with so is it load dependent, rpm or something else that causes it. I did a few pulls into 4th last night and at least once the car shifted and then the power seemed to cut out for just a second(no CEL). So I'm trying to troubleshoot a couple of things and was thinking belt slip might be a cause. I had the advancedtrack off so it wasn't the TC. I have the new tensioner with a gates green belt using the old belt routing. I was logging all my pulls. Is there something in the logs that would help calculate the boost the car is seeing based on some parameter or anything that might indicate belt slip. Thanks for any help

If belt is slipping load will drop as well as rpm, if you can log those it should tell. My bet is your not getting belt slip, according to whipple the 6 rib will hold without issue. Watching a boost gauge is very random and inaccurate Boost builds with rpm with the whipple as well. You should try and get a map sensor that can be data logged via Ngauge or whatever system your using to data log.

I looked through the logs and only saw Load as a fraction. I'm using the n Gauge to log. Any idea how to properly determine load? Knock looks good 2nd through 3rd. Timing was at 19-20.5.

I'm running 93 plus octanium with the 3.5 pulley as well most of the time boost is all over the place 10.5-12psi.. knock is usually -2.00 and timing is 18-21 depending on gear

I have a Lund boost box from my procharger. Going to hook that up this weekend and see what it says.