I'm going to contract some peoples statements here and cover the issues and points you've made/asked.
These are purely my findings and experiences of running a 300bhp GTIR on track for 7 years.
Brakes Front - Wilwoods are a good start, use ATE fluid and either Mintex 1155 or Ferodo DS2500's pads all round. Carbotech are very good (and very expensive), but if your price conscious the 55's or 2500's will do fine.
Brakes Rear - Minmum grooved discs from Black Diamond, this helps balance out the bias better, when braking. Pads as above
Braided lines all round.
Tyres - You've got that covered
Suspension - Covered (just upgrade when needed) Maybe a rear adjustable ARB if you get a lot of understeer?
Interior - Strip it all out, EVERYTHING! Get rid of everything in there, seats, door cards the lot. If its gonna be a track car only, do it right and get rid of it all (also costs you nothing to do). If you've still got the air-con system, junk it - it weights a bloody tonne.
Put in two race seats and some harnesses with your cage. Job done!
Engine - As mentioned, if you can afford to (or if its already done) get forged!
Standard engines are pretty good, but old tired ones can fail you need to make sure it's well serviced with quality oils etc. NO EXCEPTIONS.
As for the water pump pulley, I've ran a standard one for 7 years on track and NEVER had a problem. It's up to you, but personally it's never been an issue.
Front mounted oil cooler where possible, don't bother running it on the engine (topmount) that's pointless, mount it either side of your intercooler in the brake ducting for better cooler air flow.
Double core rad (or UK spec Sunny GTIR). It's the same thing and gives better cooling that the crappy JDM version.
Fuel - Covered (fuel pump)
Battery - Covered
Maintenance - You must look after it and use quality fuels and oils etc. Service the gearbox oil and diffs too. Keep on top of those things and you'll be fine.
Enjoy!
thanks very much for spending the time to write this reply
brakes:
will the poly q pads i have fitted be good enough to start with or should i really get rid for something better?
iv never really heard of ATE brake fluid, so ill have a look and upgrade to or motul rbf 6000 if you feel the dot 5.1 will boil.
rear brakes: the rear has mintex pads i think, so the plan was to use them first and upgrade as required for the first track day, etc in the pulsar...
interior: the plan for this weekend is to remove absolutely every single unecassary interior part, including any sound deadening.
The aircon system has now been removed (was shocked to how much the support bracket for the air con compressor weighed!!) also used a alternator belt from a micra...hope i read that properly and bought the correct belt?
standard seats will stay in the car to start with, but i already have harnesses to fit.
engine: its not that i cant afford to forge it, its just not the point of the car and as mentioned the missus will kill me for spending a fortune. Low budget fun car and fix it when it break
i need to check the pistons and make sure theyre standard, as i dont really know the engine or gearbox spec.
ill get a front mount oil cooler kit instead. Only reason i wanted a top mount was i didnt like the oil lines being close to the the pulleys/belts incase anything moved on track :/
Pulsarboby has a double core radiator i guess ill be purchasing soon.
Whats the general consensus on the alloy radiators on fleebay? Normally i would be told to stay away from junk ebay items and buy a forge/pro alloy unit.
is it worthwhile heat wrapping the intercooler pipes and downpipe?
