For what its worth, I am a founder member of the UK Supra club;
I have seen over 30 supra twin turbos on the rollers, some with
HKS front mounts, some with Blitz, some VVtis, some not
and from *experience* a JZA80 in standard trim with a Blitz
fmic will see something in the region of 10bhp; even doubling
the boost pressure from .7 to 1.4 AND fitting a Blitz FMIC you'd
be lucky to see an 85bhp gain !
I am amazed Blitz claim 60bhp for their front mount kit, I shall
ask their technical manager today and post his answer here.
Justin