Make a donation

Author Topic: K04 conversion!!!  (Read 2382 times)

Offline Shielsy

  • Just Arrived
  • **
  • Thank You
  • -Given: 1
  • -Receive: 0
  • Posts: 12
  • Gtiii baby
    • Email
K04 conversion!!!
« on: January 15, 2023, 07:13:46 pm »
Hi currently running a stage 1+ on my mk5 gti bwa engine looking to go for the k04 conversion so my question is where is the best place to get my hands on one online

I’m aware I will also need a new hpfp and updated intercooler car is dsg so clutch should be fine anything else I need ? And if so where have you guys found that are best to get the bits from thank you

Offline breeze

  • Always Involved
  • ****
  • Thank You
  • -Given: 27
  • -Receive: 12
  • Posts: 321
Re: K04 conversion!!!
« Reply #1 on: January 17, 2023, 09:17:01 pm »
What are your goals?

You can fit the K04 turbo / injectors and nothing else. That would effectively give you a Stage 1 Edition 30 (possibly with slightly more pep due to higher compression) after a map.

Offline Shielsy

  • Just Arrived
  • **
  • Thank You
  • -Given: 1
  • -Receive: 0
  • Posts: 12
  • Gtiii baby
    • Email
Re: K04 conversion!!!
« Reply #2 on: January 17, 2023, 10:29:28 pm »
What are your goals?

You can fit the K04 turbo / injectors and nothing else. That would effectively give you a Stage 1 Edition 30 (possibly with slightly more pep due to higher compression) after a map.

I’m aiming for 330-350 bhp. Also when you say I could just fit the k04 I would still need upgraded boost pipes etc ? Thank you 😁
« Last Edit: January 17, 2023, 10:33:48 pm by Shielsy »

Offline breeze

  • Always Involved
  • ****
  • Thank You
  • -Given: 27
  • -Receive: 12
  • Posts: 321
Re: K04 conversion!!!
« Reply #3 on: January 17, 2023, 11:14:02 pm »
K04 generally means you will need to fit the boost piping. But the hardest part of the job is changing the turbo from what I can see.

I’m rapidly coming to the conclusion that a K03 hybrid is probably the best compromise, with or without the K04 injectors to go with it. Slightly faster response than the K04 and an easier install.

Regardless of what you go for, do the maths up front.

Best value option may be to add a K04 turbo and injectors from Facebook/a breaker and get a basic stage 1 K04 map.

If you want to live the R-Tech dream (full 2+ build, have videos on YouTube etc) just be aware it will cost a lot, particularly if you aren’t doing the work.

Offline Shielsy

  • Just Arrived
  • **
  • Thank You
  • -Given: 1
  • -Receive: 0
  • Posts: 12
  • Gtiii baby
    • Email
Re: K04 conversion!!!
« Reply #4 on: January 17, 2023, 11:28:47 pm »
K04 generally means you will need to fit the boost piping. But the hardest part of the job is changing the turbo from what I can see.

I’m rapidly coming to the conclusion that a K03 hybrid is probably the best compromise, with or without the K04 injectors to go with it. Slightly faster response than the K04 and an easier install.

Regardless of what you go for, do the maths up front.

Best value option may be to add a K04 turbo and injectors from Facebook/a breaker and get a basic stage 1 K04 map.

If you want to live the R-Tech dream (full 2+ build, have videos on YouTube etc) just be aware it will cost a lot, particularly if you aren’t doing the work.

Haven’t looked into k03 hybrids much will definitely do a bit of research on them.
Ideally I’d be happy within the low to mid 300bhp range nothing crazy like the guys on YouTube with 400+ builds. don’t plan on getting rid of my mk5 anytime soon so may start with what you’ve suggested and go just the k04 or k03 hybrid way and see where things go in the future. Appreciate the help  :driver:

Offline pudding

  • Global Moderator
  • Just look at my post count
  • *
  • Thank You
  • -Given: 2
  • -Receive: 690
  • Posts: 8353
Re: K04 conversion!!!
« Reply #5 on: January 19, 2023, 03:32:38 pm »
K04 generally means you will need to fit the boost piping. But the hardest part of the job is changing the turbo from what I can see.

I’m rapidly coming to the conclusion that a K03 hybrid is probably the best compromise, with or without the K04 injectors to go with it. Slightly faster response than the K04 and an easier install.

Regardless of what you go for, do the maths up front.

Best value option may be to add a K04 turbo and injectors from Facebook/a breaker and get a basic stage 1 K04 map.

If you want to live the R-Tech dream (full 2+ build, have videos on YouTube etc) just be aware it will cost a lot, particularly if you aren’t doing the work.

Haven’t looked into k03 hybrids much will definitely do a bit of research on them.
Ideally I’d be happy within the low to mid 300bhp range nothing crazy like the guys on YouTube with 400+ builds. don’t plan on getting rid of my mk5 anytime soon so may start with what you’ve suggested and go just the k04 or k03 hybrid way and see where things go in the future. Appreciate the help  :driver:

The 400+ builds are all hybrid K04s.  Stock K04 maxes out in the mid 350s.  Well, 330hp actually (BorgWarner factory quote), but we have to account for the usual TikTok, Insta, Facebook, YouTube dyno Bull sheet.

Fitting a K04 is actually a piece of p1ss.  Did it in May.  It's all the dicking about afterwards with mapping etc that is the bigger issue.



2007 ED30 | 2009 TDI 140 | 2016 BMW 330D

Offline Shielsy

  • Just Arrived
  • **
  • Thank You
  • -Given: 1
  • -Receive: 0
  • Posts: 12
  • Gtiii baby
    • Email
Re: K04 conversion!!!
« Reply #6 on: January 19, 2023, 10:12:01 pm »
K04 generally means you will need to fit the boost piping. But the hardest part of the job is changing the turbo from what I can see.

I’m rapidly coming to the conclusion that a K03 hybrid is probably the best compromise, with or without the K04 injectors to go with it. Slightly faster response than the K04 and an easier install.

Regardless of what you go for, do the maths up front.

Best value option may be to add a K04 turbo and injectors from Facebook/a breaker and get a basic stage 1 K04 map.

If you want to live the R-Tech dream (full 2+ build, have videos on YouTube etc) just be aware it will cost a lot, particularly if you aren’t doing the work.

Haven’t looked into k03 hybrids much will definitely do a bit of research on them.
Ideally I’d be happy within the low to mid 300bhp range nothing crazy like the guys on YouTube with 400+ builds. don’t plan on getting rid of my mk5 anytime soon so may start with what you’ve suggested and go just the k04 or k03 hybrid way and see where things go in the future. Appreciate the help  :driver:

The 400+ builds are all hybrid K04s.  Stock K04 maxes out in the mid 350s.  Well, 330hp actually (BorgWarner factory quote), but we have to account for the usual TikTok, Insta, Facebook, YouTube dyno Bull sheet.

Fitting a K04 is actually a piece of p1ss.  Did it in May.  It's all the dicking about afterwards with mapping etc that is the bigger issue.

My only issue with the k04 is that it isn’t easily got unless bought new as I’m in Ireland. Switched my Facebook marketplace location to the uk and there’s tons but no ones intrested in shipping it over 😂.

K03 hybrid seems to be a good option for me but what gains do you reckon I could get out of it. ?


Offline pudding

  • Global Moderator
  • Just look at my post count
  • *
  • Thank You
  • -Given: 2
  • -Receive: 690
  • Posts: 8353
Re: K04 conversion!!!
« Reply #7 on: January 20, 2023, 09:02:33 am »
Is getting stuff to Ireland a major issue then?  I order stuff from Prentice BMW in Portadown over to England and its cheap and easy enough, so not sure why it's an issue in the opposite direction  :grin:

I have zero experience with K03 hybrids but in theory you should get somewhere close to a K04.  It just depends what size turbine and compressor wheels they use.


2007 ED30 | 2009 TDI 140 | 2016 BMW 330D

Offline Shielsy

  • Just Arrived
  • **
  • Thank You
  • -Given: 1
  • -Receive: 0
  • Posts: 12
  • Gtiii baby
    • Email
Re: K04 conversion!!!
« Reply #8 on: January 21, 2023, 06:26:30 pm »
Is getting stuff to Ireland a major issue then?  I order stuff from Prentice BMW in Portadown over to England and its cheap and easy enough, so not sure why it's an issue in the opposite direction  :grin:

I have zero experience with K03 hybrids but in theory you should get somewhere close to a K04.  It just depends what size turbine and compressor wheels they use.

It’s not a major issue getting stuff to Ireland but the used market in Ireland for the likes of a k04 is an issue. K04 kits in the uk go on fb marketplace for 600-1200 from what I can see but finding one in Ireland is very hard and if you do find one could be paying 1500 for the kit. I think this could just be down to the fact that the uk has more garages offering tuning services where as Ireland doesn’t offer great tuning facilities.

Saying that I have actually found a guy that has done the k04 conversion on multiple mk5s here in Ireland and from what I heard is seems to know his stuff when it comes to mk5s so think I’m gonna dodge the k03 hybrid and go with the k04 will keep everyone updated

Offline OllieVRS

  • Always Involved
  • ****
  • Thank You
  • -Given: 16
  • -Receive: 16
  • Posts: 329
Re: K04 conversion!!!
« Reply #9 on: January 21, 2023, 11:31:01 pm »
There's a new Borg Warner K04 for sale there in Dundrum on Adverts for €1200.

If I were you I'd call around to scrap yards asking if they've got an S3s from 2006-2013 or TTSs from 2008-2013 or Cupra Rs from 2010-2012 as they'll all have a k04 turbo (correct me if I'm wrong on these @Pudding ).

If you do find more than one in a scrapper obviously go for the lower mileage one, but in Ireland the market is so small that you'll rarely get a choice. It's cheaper than importing a UK one, but far far dodgier.

Also if you're feeling brave, ring up FK Volkswagen Liffey Valley's parts department and who knows, maybe they'll give you a quote for a new one that isn't too ridiculous  :happy2:
'06 Skoda Octavia vRS TFSI

Offline pudding

  • Global Moderator
  • Just look at my post count
  • *
  • Thank You
  • -Given: 2
  • -Receive: 690
  • Posts: 8353
Re: K04 conversion!!!
« Reply #10 on: January 24, 2023, 01:58:11 pm »
There's a new Borg Warner K04 for sale there in Dundrum on Adverts for €1200.

If I were you I'd call around to scrap yards asking if they've got an S3s from 2006-2013 or TTSs from 2008-2013 or Cupra Rs from 2010-2012 as they'll all have a k04 turbo (correct me if I'm wrong on these @Pudding ).

If you do find more than one in a scrapper obviously go for the lower mileage one, but in Ireland the market is so small that you'll rarely get a choice. It's cheaper than importing a UK one, but far far dodgier.

Also if you're feeling brave, ring up FK Volkswagen Liffey Valley's parts department and who knows, maybe they'll give you a quote for a new one that isn't too ridiculous  :happy2:

Yep  :happy2:  Any car with a K04-064 turbo. 06F145702C


2007 ED30 | 2009 TDI 140 | 2016 BMW 330D

Offline LC5F

  • Just look at my post count
  • ******
  • Thank You
  • -Given: 16
  • -Receive: 80
  • Posts: 1110
Re: K04 conversion!!!
« Reply #11 on: January 27, 2023, 01:06:05 pm »
I understand the joy of a K03 hybrid is bolt-on, the quicker spool-up of the K03 and a better diverter valve location -but not easier to get to.

Whatever way you go - don't forget to budget for remapping

Offline Shielsy

  • Just Arrived
  • **
  • Thank You
  • -Given: 1
  • -Receive: 0
  • Posts: 12
  • Gtiii baby
    • Email
Re: K04 conversion!!!
« Reply #12 on: January 29, 2023, 10:34:05 pm »
I understand the joy of a K03 hybrid is bolt-on, the quicker spool-up of the K03 and a better diverter valve location -but not easier to get to.

Whatever way you go - don't forget to budget for remapping


I got a quote of €4250 so roughly £3700 with everything brand new supply and fitted. Honestly think price is a bit steep but then again that including the price of stage 3 software and stage 3 dsg map what do you guys think that’s on a k04 setup