B W

What @Enivob said. Try to scale the Velocity on your impact object.

So I have found an Solution which works and I thought I would share it.
After you import your geo you have to use a Polyfill. Then you convert your Geo to a VDB and then back to Polygons.
I used a Polyreduce to speed things up.

Hope it Helps

So is there a way to make a proper “volume” of this kind of model which I can use for a FLIP sim.
Somehow converting to VDB doesn't work and the particles go straight through.
I was thinking of remodeling so it doesn't have any gaps or open faces, but i was wondering if there is a faster way?

Thanks in Advance