The turbo header you are attaching in the turbo's cfg is defined in these files (looking at the rdb) :
script parts\engines\Toyota_4A_GE\scripts\stock\Toyota_4A_GE_exhaust_header.class
native part parts\engines\Toyota_4A_GE\cfg\stock\Toyota_4A_GE_exhaust_header.cfg
The turbo header java you pasted I think can not be the java referenced in the rdb because if the first class name does not match the .class file name slrr crashes (I seem to remember)
Are you sure you are referencing the correct files in the rdb? (the ones you shared)
(the javas look good aswell as far as I can tell)
