Ragdolling giants?

Hi, I’m attempting to ragdoll a character 40x larger than the UE Manny. The ragdoll sim is very ‘floaty’, joints don’t bend as much as they do when applied to a standard size character, and the character never really comes to rest. I’m assuming this has to do with scale (I’m simply scaling up a skmesh, tried doing this both inside and outside UE). I tried playing with mass scale on the sim bodies in PHAT to no avail.

Any tips on how I might improve this?