I am running the exact same set up as you...( motor, esc, batt. ) in my diffs is as follows:
Front 20K
Center 20K
Rear 7K
I have minimal ballooning and it rips. Nice to see more Mugens here
1. MBX-6 T8 1900KV, RX8 ON 4S
2. MBX-5T 1520, MMM ON 5S
3. MBX-5 ONROAD CONVERSION 1515, MMM ON 5S
4. MRX-3 ON ROAD CONVERSION 1512, MMM ON 6S
5. TEN T 2650 T8, MMP ON 3S