Wierd Timing

[Waldo_87]

I have an RB25DET

trying to set timing after being in the shop to get new parts put on

a mate set the timing and it ran great pulled hard and jus drove great

after getting the timing checked at the shop they said it was on 25 degrees and they pulled it back to about 17 degrees

drove like a bucket since

first initial bit of revs pulls normal then just seems to die off n not pull hard

i checked my timing today and advanced it to 25 degrees again

once the car warmed up i checked it again and it read bout 16 degrees

took it for a drive and it pulls good all through the rev range now

it says on the bonnet 15 degrees at 650RPM, but by my tacho seemed to be reading bout 750-800RPM

i also unpluged my TPS and made no difference

i have,

- 3 1/5 inch exhaust

- iridium plugs and splitfire coils NEW

- front mount running 11-13psi with stock turbo

any ideas what could be happening?

is it dangerous to drive like this?