Milltek cat back system 10% more power ?

[linkman72]

Right lads n lasses I have been sniffing around for a replacement system for my 03 Avant and found an ad on scambay for a milltek catback - item number - 270829660460.

Firstly I am a little worried about the increase in cabin noise so can anyone report back on this ?

Now this ad claims 10% power hike from the exhaust but I am a little sceptical, has there ever been a dyno print out for a milltek ?

Or can anyone substantiate this claim who has had one fitted ?, I am not questioning the retailers honesty but buying aftermarket parts in this country is like the wild west and I aint a good shooter

Any help gratefully approeciated cos I dont want to waste £800 odd squids having an exhaust fitted I wont like

[Ian_C]

There is no performance increase from catback - whether resonated or non-resonated.

[linkman72]

ooooh I knew it must have been a fib

[Ian_C]

You'd get more performance increase between 95 and 98 (RON) than an S4 with a stock exhaust and a non-res cat back

[S4 V8]

I gained about 9hp and 13ftlb of torque from my cat back. That is a custom 2.5" catback with x-pipe. If you look at the standard exhaust there is significant room for improvement. There is a very squashed section of pipe just after the centre box's on the standard system. If your looking at getting the Milltek you might be worth waiting a few months.
Biggest gains will be from decat downpipes, piggied, or sports cat'd downpipes. Best road legal arrangement is with the sports cats in a downstream position similar to where the standard main cats are.