Hi again im about to do some work to my bf f6 its got a zf 6sp how huch power can the engine and gearbox run daily safely I read a lot about the ba's but I here the bf's are different. How far can you go with the bf f6 intercooler and valve springs. Also what is the first thing to runout of legs eg. injectors or fuel pump any help will be much appreciated.

Zf 6 speed can go anywhere from low 300ish to high 400s depending on drive style and luck (and the amount of ks the box has).

Engines fine for the 300-400 zone on 98 and 400s on e85 but always risky once you see the bigger numbers.

Intercooler wont do much better than 300-320 without cuasing heatsoak and loss of power after a squirt or 2.

Injectors are the first thing you should do along side the cat/dump to get the most bang for buck out of the car before it gets expensive.

And if you drive it like a cock, then it'll have a short lifespan.

I commuted in my ute every day, before moving offices and using the train now.

But I'd rarely even see 5psi boost on the trip to work so it was doing no more work than a stock trans.

It's all about duty cycle IMO.

Same as engine life.

I drove mine for 200,000km (half that with 320rwkw) before finally getting it rebuilt. One fluid change at 150,000km in there and once it was warmed up each day I love to give it power on the freeway onramps etc.

However it was absolutely fried when the tuner pulled it apart, he was shocked it even went down the drag strip. The friction material was all gone on many of the clutch packs...just metal on metal. Do not recommend.