So the Carbon buildup issue on the FSI is well known as are the inlet flaps snapping (mine hand not) however, as a precautionary measure I booked the car into VRS Northampton this week for a full carbon clean, inlet flap delete, Remap and dyne's before and after.
To me the car never really felt down on power, always pulled nicely and was a joy to drive, however, the dyno revealed a different story as the car only made 362bhp and 382lb ft - quite different from what its meant to do as stock power is 444bhp new.
This is what was inside:
https://youtu.be/wC1VrqelHWQ
So they set about cleaning it all out, deleted the flaps and bolted it back together:
They chucked her on the dyno and she made 420bhp - much more respectable, however a problem revealed itself when the inlet flap motor was burnt out, yes the flaps were deleted, but the burnt out motor and sensor had logged an error that wouldn't clear without being fixed, a new part was sourced and dropped in, error cleared, back on the dyno and set about remapping.
Initially they dropped an APR off the shelf map on it and she made and extra... 4bhp - Will decided to sack the map off and custom map the car - the result:
480bhp & 398lb ft of Torque - a massive 118bhp up on the amount of power she was making when I dropped her off, the new power output is more impressive when you consider nigh on 400hp of it is available at the wheels.
Needless to say, it fully showcases that if you have an S8, its worth doing the carbon clean, flap delete and remap. Its shocking that FSI's do this in the first place, B7 RS4s are well known for it, but I certainly didn't expect mine to be so bad given its history, the way its been looked after and how I drive it.
The drive home was... boring, traffic all the way, nose to tail, horrendous rain... the car felt much smoother though, but I didn't get about 40, so tomorrow I'll be out for a proper blast
EDIT: Dyno run video -
https://youtu.be/kFbj66fHAK4