the 28 and td04 have very similar spool times with a nice TBE exhaust - not too many rpm in difference..
essentially a big bang almost the time the 04 came in play - only harder and lasts longer..
how i knoiw
done the exact some swap and my reaction was:
similar spool rate
more power at lower rpm and not running outta puff at 5g..
only ran the 28 at 15psi so well within its safety range and fair bit more headroom to go..
i say anything between 16-18 will give a fairly HARD whack of power and not run outta puff till in the 7g rpm range..
although best to upshift by 6.5-7 if on standard internals lol..when pushing it that is..
you will find the 28 really responsive and have a decent power curve for standard motors with simple bolt on mods etc..
i prefer the 28 over the 30 for street driving..
the combinations i have used so far are
td04, tdo5,tdo6 hybrid
vf23,28,24,30,22
best for street aka daily driver with a PUNCH when needed was the 28..
some other turbos will give more punch at higher rpm but then depenmds what are your preferences as to where you want your power..
personally i like a fair bit of low end with some reserve in the top end when i feel like a blat down some back road but since mostly i need to get to work on time everyday through traffic, i prefer the 28's low end and top end compromise