Oh and to add to the thread, the main companies that do “tunes” are:
GIAC
Unitronic
Wetterauer
powerchip
Neuspeed
upsolute tuning
PES (they apparently make a standalone chip aside from the supercharger)
no point in posting numbers, they vary between each one but they all over the same thing, increased rpm limiter, removed speed limiter, and change fueling around and make it feel like theres better throttle response. Noone really seems to be happy with them as the end result is worse MPG and no real performance increase.
There’s the sprintbooster, but that just changes how much throttle the pedal gives the engine when you push it down, again no actual performance gain.
hyperflow CAI… doesnt do anything according to everyone that has one.
a lot of companies that do catbacks, no point in listing them all the S4 ones are compatible with our cars as well. As they are just the catback itself no real performance gain there either.
Supersprint makes headers and downpipes, but they are really expensive and have to be imported from europe. Labree makes HFC’s and downpipes, again pretty expensive.
I think the pattern is obvious, most of the stuff is a waste of money as it doesn’t do anything, and anything that does is just marginal in terms of gains and costs a lot.