I've owned my 2001.5 S4 since late 2005, over the course of these years the car has developed into a very well rounded car.

I built the car in my garage running a custom GT28 kit. Mod list is pretty small, All bone stock from the heads to oil pan besides the list below etc.

Rosten rods, new bearings with all the necessary replacing components when building any motor.
ARD Bi-Pipes
Vast stage 4 clutch
1 piece billet steel flywheel
Vast meth kit
Custom 3.5" exhaust fitted with 2 reflective resonator mufflers where the cats use to be and 2 regular mufflers towards the rear bumper.
Custom 750 Bosch single tip titanium injectors, AMAZING PIECE
4" Cold air intake with 95mm Maf
Vast custom pump file for now.

The car is actually over the factory weight, 22lbs in heavier/taller wheels and tires, GT kit weighing near 40lbs over stock, plus the 2 gallon meth tank in the trunk with pump added another 25lbs etc.

First file the car would run very consistent 2.90 3rd gear pulls, no meth, pump only, peak boost of 20lbs was reached around 3800rpm. More tuning with meth and upping the boost to 24-25lbs should bring this tank down to the 2.60 or better mark.

Car makes instant boost in all gears, almost hard to keep the car out of boost haha.

I've been in all size GT cars, RS6 cars etc and none were this well rounded, power band is 3400rpm to 76-7800rpms on 99% stock parts etc.

Will keep the progress updated, hoping for 525-540whp on our local rough Mustand dyno @ 25-27lbs.