Will 630cc injectors be too big to run about 260 bhp on a 1.8T engine with K04 turbo, or should they be ok?
They are a little too large and will make tuning a little more difficult in the partial throttle transitions but it can be done, it just takes more time.
Get a set of 450 cc and make life easier…
IIRC the stock injectors can do 260