Agu tune up!!

[coolio]

simple not gonna happen unless you have some serious cash i have spent in excess of 3k and im still not gonna reach the 300bhp mark

hybrid the k04 and  fit a bigger maf will get u near the 300bhp barrier ,the most restricted area on the k04 is the exhaust manifold , if u get the high flow manila it will break the 300 bhp barrier ! Fit a bigger throttle body (70mm) will gain few bhp too  , then u can get Ross racing or ABD inlet manifold these will give u about 10 bhp !

but I personally think  around 280bhp on the mk4 is more than enough !   

[topher]

turbo & lines
manifold
downpipe
intercooler
fuel pump & injectors
engine mounts
clutch

boost gauge, afr gauge, oil temp/pressure gauge, brakes, suspension all recommended extras

[tom-gardiner]

Only a mug or a nutter can lose an evo

or the 18 year olds round here that buy the older evo 1's 2's 3's and 4'd that are imports and booked as standard 1.8's and havnt got a clue that you have to slow down round corners and round abouts! not even insured when they hit someone!

[Sabre K]

turbo & lines
manifold
downpipe
intercooler
fuel pump & injectors
engine mounts
clutch

boost gauge, afr gauge, oil temp/pressure gauge, brakes, suspension all recommended extras

+
Fuel Pressure Regulator
Limited Slip Diff
Sports/Upgraded O2J Gearbox (e.g. SQS Racing)
or O2M Gearbox, Linkage, Shifter, Axles, Hubs, Starter Motor, Alternator

Std O2J will fail, question will be if the casing will stay together (if you are lucky)

[Wazzzer]

02M's aren't renowned for being THAT strong though are they?

[DarkGti]

nothing wrong with the 02J box, the only thing that will fail if your running big power is your clutch if not properly upgraded

[Sabre K]

02M's aren't renowned for being THAT strong though are they?

Not saying 02Ms are bullet proof, but not have many people talking about their diff pins shearing or gearbox exploding.
iirc:

02Js fitted for 150-180 std from VW
02Ms fitted for up to 225 std from VAG

I can't confirm 02M will cope with 300 bhp long term, would it not last longer than a std 02J?

nothing wrong with the 02J box, the only thing that will fail if your running big power is your clutch if not properly upgraded

Afaik 02J (atleast older versions e.g. ECW for AGU have weak rivets on differential to final drive gear, that have been known to shear, search around eg)
http://uk-mkivs.net/forums/p/274510/1808684.aspx
http://www.intengineering.com/VW/18T/Drivetrain/Peloquin-02J-Torsen-Limited-p6302523.html
http://www.volkswagenspares.com/page.php?page=Gearboxes

Bit tempted to get an SQS Gear kit if I turn the Golf to a track day car.
http://www.sqsracing.com/kategorie-produktu/23:competition-gear-dog-box-kit-racing-gearbox