Audi S4 B9 (2017) Stage 2 tune

kieran nice

New Member
Hi All,
I'm looking at going for a stage 2 tune for my 2017 Audi S4 B9.

I'm looking at

ECS Intercooler
Wagner intercooler
REV 9 Intercooler

CTS Turbo decat
Milltek Decat

Ram air oversized stage 2 filter.

Can anyone recommend a good tuner for Stage 2 please?
Ideally I'd want little bit more noise out of the car and the gearbox mapping + soft rev limiter removal.

Few questions:

I'm from the UK, its currently 3 degrees here -
Will the S4 benefit from a upgraded intercooler, I won't be tracking my car, its a daily drive, I will do a few spirited runs but not back to back runs, has anyone got any experience with this and also which intercooler would you guys choose between Wagner and ECS and REV 9 please?

Is gutting your Cat an option?
Milltek and CTS offer products for around £500, has anyone has these fitted to their Audi S4 B9s? Do you get drone, how do they sound?

Tuning - going rate for stage 2 appears to be around £900, not sure if anyone has had any experiences they would like to share regarding stage 2 tune.
What power have people been getting, i've seen 450bhp-480bhp.

I have 440 BHP with APR Stage 1 - IMHO no sane reason to have more power - 3.5sec 0-60.
The law of diminishing returns will likely see you spend a small fortune in trying to derive equal or slightly more with potentially unknown results.

i plan to go APR stage 1 when my warranty expires next year, it's all i'll need. are you coming from bone stock? If so, it's probably worth just going for a tune first, as Dingah says, you may find that's enough. If you want to go further most tuners with off the shelf tunes (e.g. APR, EPL) will advise what supporting mods you'll need to extract more power as you go up the stages. I think APR suggest a bigger IC. There's a huge thread on Audizine about it (search google for "b9 s4 apr development car is here". The tune is relatively new given the ECU was only cracked last year so all the stuff about that is in the last 10-15 pages of that thread


Registered User
The APR stage 1 power wi be dependent on fuel - Dingah and I both went with 98ron - which APR claims is good for 440


Registered User
@Spearo + @Dingah from Downundah
Thank you so much the both of you for chiming in, I'll go that way too.
Here's what APR recommends concerning running with a lower RON. It's common sense, but good to know.


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