STAGE ONE:
Milltek cat back Resonated = loud, non resonanted= louder. But can be boomy- not that i noticed it. May provide a small increase in BHP.
Stage one generic remap. Together with the Milltek, you should see noticable gains of BHP of upto 50hp depending on the mapper.
TCU map (gearbox) A must once the engine is remapped to help cope with the increase in torque.
DRC replacement Various solutions available in the form of coilovers. Budget dependant. But your DRC WILL fail.
Diverter valves (DV's) Again various solutions available, but you will need to replace these to cope with the extra boost.
Air filters ITG seem the prefered choice, and again good results have been achieved with these foam filters.
Phaeton cooling ducts A very cheap solution to increase the performance of OEM brakes.
Big brake upgrade replacement of front OEM C5 disks with OEM C6 disks.... You will notice the difference
Caliper upgrade Replacement of the front C5 calipers with C6 calipers.
Rear brake upgrades Various options available, but require both disks and calipers
Anti Roll Bars (sometimes called ARB's or sway bars if you are from across the pond) It would appear that Hotchkiss are the prevelent force in this area. These will stiffen the car up and improve handling 100% when used in conjunction with coilovers.
STAGE TWO:
Full Milltek with hi flow cats or no cats This will allow the engine to "breathe" more easily and also increase turbo spool up time.
Custom remap This is where a mapper will sit in your car and do numerous "runs" altering the map of the ECU to optimise the output for your particular car. Sometimes these maps need continuos "tweeking" as you alter bits to your car. But power gains are fantastic.
Intercoolers Big intercoolers help with the cooling process and are a must if chasing 520+ BHP.
STAGE THREE:
Big turbos You will require these to get over 550hp.
Tubular manifolds To cope with the increase in all things gassy
Fuel pump A larger CC fuel pump
A manual gearbox conversion This will allow you to run silly torques. Rule of thumb on the RS6 slushbox, even with TCU mapping is 600ftlbs max.
This list is by no means definitive, but meant only as a guide as to what you can do, and in many cases has been done.
Not all mappers are the same, some are very good and some are very bad. Research well, reap the rewards. Get "joe the chipper demon" to do it from next door, and i hope you have £20k to spare for a new engine.
Anyhoo... hope this helps, and maybe you will have a rough idea of whats what.
Now <beep> off and leave me alone.
Mooch
