Audi S3 8L tuning


Full member
South wales
Audi s3 8l
Hi guys, I have an audi s3 8L with a snapped cam belt due to a seized water pump. Sods law this happened 2 days before it was booked in to be changed
Thankfully I have a very good mechanic friend on furlough that is re building it for me.

So my questions are: whilst having the engine stripped we are talking about a possible turbo upgrade either the f23 k04 or the K04-0023S. Which one would you recommend if any?

Would I need to upgrade any other parts at the same time? Ie. The intercooler or would it be okay with just the turbo and remap?

There is induction mods on already, however I believe there is a boost leak somewhere. We need to rebuild before finding where the problem is occurring obviously.

Any advise would be great thanks guys
Our thoughts are turbo and a remap.
AFAIK there is pretty much no physical difference externally between these turbo units, except a subtle variation in the downpipe flange. Internally the F23 is better IMHO but it depends if your mapper has a good profile and setup for it. Getting the most from any turbo upgrade depends on the mapper.

The s3 is well setup for handling more power and injectors etc should work well. I would however get the head polished, ported and 5 angle valve job. It will make the engine feel more torquey and you'll get a little more power from it.

Intercooler size just means that heat soak takes longer to take effect so if you are doing short high power burst the OEM intercooler is fine, if you are doing track days with long full boost sessions then a FMIC makes sense, or at least an upgraded intercooler.

If you got the engine balanced an blueprinted it will allow a higher redline, but you start talking about a lot of extra money for not a lot of extra power.
Obi_waynne, legend for that. A lot of useful feedback there. I am going to go for the f23 turbo. The head is going to be port polished by my mate. I haven't actually got a mapper lined up, the one I've used in the past on my volkswagen T5 unfortunately doesn't do the S3 8L but I will shop around for the best service.

As for the intercooler I will hold off... in the future I would like to take it to a track but only maybe once just to get the full experience in a controlled environment. So I don't believe spending 600+ on an intercooler is efficient for me.

If possible could you confirm this is this right turbo please.

Thanks again for your feedback, was very helpful. Do you own an S3 yourself?
My last 3 cars have been A3's and I've had most of the engine options over the years, from the 1.8T to the 2.0 TFSi and diesel, currently I'm on a 1.4 TFSi. I needed 4 doors and at the time the S3 only came as a 3 door, now I have to look at budget and running costs so the S3 is a distant dream for me.

I can't really comment on parts or suppliers directly, as I will become personally liable should you hit on any issues fitting it and there are lots of factors to take into account when buying turbos...

This is a general word of advice without me even looking at the link you've suggested.

Be careful with cheap turbos on ebay, many times they are substandard imports that break very soon after fitting and getting money back or warranty claims on imported turbos can be very challenging - choose a reputable local supplier with good feedback and make sure it has a warranty. Exchange turbos are often good value options. Better still if you get the turbo supplier to fit you have a one stop shop to iron out any issues that may crop up.
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Ah yeah great! You've had a fair few audis then, I like it.

Mm yeah im going to take your advise and not go for the ebay f23 turbo as its £138 and that does seem way too cheap. Realistically im not in the right place to spend 1000 on a turbo when the cost of fixing it could be up at that price too.

Just going to port polish it, clean up the whole engine and intake systems and do a remap. I will post some photos once its done

Thanks for your advise once again dude.
I look forward to seeing your photos. (You'll need to get past the 10 posts limit to get an upgraded account before you can post pics, but you'll rack that up in no time I'm sure).

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