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The facts about the K03 Turbo!

Discussion in 'A3/S3 Forum (8L Chassis)' started by Gambba, May 14, 2004.

  1. Gambba
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    Gambba Active Member

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    As some will be aware following on from a discussion on one of the boards I decided to drop Borgwarner an e-mail asking them some simple questions regarding the K03 turbocharger and what some have called the K03S.

    The Question
    [ QUOTE ]

    I type this e-mail to you on behalf of many Audi enthusiasts, and myself as an Engineer, who ponder on the same question, as to the interchange-ability of the K03 and K03S turbocharger units.

    As a member on one of the largest Audi forums on the web
    (www.audi-sport.net), as well as a member on many other Golf and Audi forums, I have often seen this subject raised but with no definitive answer ever given, due to a lack of information available. Audi dealers are not technically inept enough to offer an answer, Audi UK are not interested in answering and most aftermarket tuners opt for either the K04 or other brands of turbo so appear not to of looked into the subject.

    So the questions are simple;

    Can the K03 turbo (5303 988 0011 or 5303 988 0053) be directly replaced by the K03S (5303 988 0052 or 5303 988 0026) in terms of the intake and exhaust housing dimensions?

    Is K03S the correct designation for the latter turbo mentioned above?

    Obviously if a K03S was fitted an engine map could be changed to suit, but would a standard turbo map for the K03 be suitable for running a K03S on?
    or would a loss of power be expected? and are the characteristics of the two very similar?

    I hope you can assist with the above and any information you could supply would be gratefully accepted.

    It's taken me a couple of weeks to get a response, but the response was well worth it, I think yóu'll agree.


    [/ QUOTE ]

    The Answer
    [ QUOTE ]

    Dear Sir,

    thank you for your interest in our products.

    First of all, we don't produce any turbo that we call K03S. But I hope I can
    answer your questions with the following explanations.

    All the following turbos have the same installation dimensions and
    thermodynamical performance. The differences are only in the actuator that
    opens the turbine bypass valve:
    K03-011 (5303 988 0011) 150 hp, 65 N actuator
    K03-026 180 hp, 85 N actuator
    K03-035 180 hp, 85 N actuator
    K03-044 150 hp, 65 N actuator
    K03-045 156 hp (Ibiza Cupra), 85 N actuator with 2 ports
    K03-049 150 hp (Sharan/Alhambra), 65 N actuator
    The 180 hp versions have an actuator with a higher opening force due to the
    higher exhaust gas pressure (which is a consequence of the higher boost
    pressure). Otherwise the valve would be pushed open by the exhaust gas
    pressure.

    The following turbos are a further development (since 2000) and have an
    improved and slightly larger compressor while using the same turbine (still
    with the same installation dimensions):
    K03-052 180 hp, 85 N actuator
    K03-053 150 hp, 85 N actuator
    K03-058 150 hp/180 hp, 85 N actuator

    Consequentially, putting a 180 hp turbo on a 150 hp engine will not bring
    about any change in performance, but putting on a K03-052/053/058 instead of
    the older versions will bring a slight improvement in engine efficiency.
    Additionally, with re-mapping the ECU you can achieve about 215 hp without
    danger of overspeeding the turbo. With the older turbos, 195 hp is the
    limit.

    With the K04 that's also commonly used (5304 950 0001) the power output
    should not be more than 220 hp. That means, changing a K03-052/053/058
    against a K04 does not make a lot of sense.

    I hope that these details answer your questions. If you need more info, one
    of our service distributors will be glad to help you. Their addresses are on
    our website www.turbodriven.com.

    Mit freundlichen Grüßen/Best regards,
    BorgWarner Turbo Systems GmbH


    [/ QUOTE ]

    Big respect to Christian at KKK for taking the time to respond, especially to an end user like myself.
    #1
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  2. JamesA3
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    JamesA3 Member

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    I'm confused, why is he saying with the K04 power output should not be more than 220hp?
    #2
  3. Gambba
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    Gambba Active Member

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    Because that would seem to be what KKK specify as the general operational limit of the turbo....not necessarily meaning this is the max spec of it, just what they spec it for.

    Moderators, I have no idea why two threads have appeared but can you delete one, obviosuly transfering the comments of the deleted one to the other /ubbthreads/images/graemlins/beerchug.gif
    #3
  4. JamesA3
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    JamesA3 Member

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    Interesting, I was thinking of changing my turbo and figured it would be cheaper to swap it for a turbo thats already used on the S3 and is good for 270ish bhp.

    food for thought anyway mate thanks for the info
    #4
  5. RichA3Turbo
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    RichA3Turbo ...Watching you! Staff Member Moderator

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    [ QUOTE ]
    James M said:
    Interesting, I was thinking of changing my turbo and figured it would be cheaper to swap it for a turbo thats already used on the S3 and is good for 270ish bhp.

    food for thought anyway mate thanks for the info

    [/ QUOTE ]

    To be honest, Doing this is NOT cost effective! For the extra couple of ££ it would cost for a K04 conversion, you may aswell get a proper turbo conversion. The K04 is obviously a reasonalbe step up from a K03, BUT its still not a very good or efficient turbo. the IHI turbo creates peak boost only 200rpm higher than a K03, and is efficient upto 8000rpm! this means you WILL create peak power at the redline! A much better option for not much more money. You know it makes sense! /ubbthreads/images/graemlins/groovy.gif
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  6. JamesA3
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    JamesA3 Member

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    of course it makes more sense however at £2895 its more than an extra couple of quid I mean how much would a K04 cost?
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  7. RichA3Turbo
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    RichA3Turbo ...Watching you! Staff Member Moderator

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    [ QUOTE ]
    James M said:
    of course it makes more sense however at £2895 its more than an extra couple of quid I mean how much would a K04 cost?

    [/ QUOTE ]

    £2500!
    #7
  8. RichA3Turbo
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    RichA3Turbo ...Watching you! Staff Member Moderator

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    Remember the K04 will use a new manifold, MAF sensor (S3/TT use a 75mm, A3 uses 70mm), turbo, twin cats, exhaust system, labout for fitting, remap .etc .etc

    Rich
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  9. JamesA3
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    JamesA3 Member

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    oh more to it than I thought, in which case better off with the IHI

    wouldn't mind a ride in yours when you get it done /ubbthreads/images/graemlins/smile.gif
    #9
  10. RichA3Turbo
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    RichA3Turbo ...Watching you! Staff Member Moderator

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    [ QUOTE ]
    James M said:
    oh more to it than I thought, in which case better off with the IHI

    wouldn't mind a ride in yours when you get it done /ubbthreads/images/graemlins/smile.gif

    [/ QUOTE ]

    Will be a long wait i think /ubbthreads/images/graemlins/frown.gif Will take me a while to save! /ubbthreads/images/graemlins/grin.gif
    #10
  11. JamesA3
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    JamesA3 Member

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    the only thing thats putting me off is I would be looking to sell my car in two years as it has 42k on it already and I'm not sure its worth it
    #11
  12. RichA3Turbo
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    RichA3Turbo ...Watching you! Staff Member Moderator

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    [ QUOTE ]
    James M said:
    the only thing thats putting me off is I would be looking to sell my car in two years as it has 42k on it already and I'm not sure its worth it

    [/ QUOTE ]

    Well.. if your planning on selling it, then its probably not worth doing.

    Im not planning on selling this... EVER.. When i get a new car it will be aswell as this one not instead of so not an issue. This will be turned into my track/sprint car eventually

    Rich
    #12
  13. HTC
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    HTC Active Member

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    It can be cost effective for some of us. I have a K03 from a 180bhp car waiting to go on my engine. I got it for £60 and will fit it myself, as with all the other work on my car.

    I have spoken to jabbasport who say the car will be fine to drive with the new turbo up to their place for a remap.

    So for the cost of a remap + the cost of the turbo (and a few gaskets) I've got a little more power than the average remapped A3.

    BTW, superb post Gambba. This is exactly the info I've been after for a while. /ubbthreads/images/graemlins/beerchug.gif
    #13
  14. RAPS3
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    RAPS3 Active Member

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    Thought this would be a good thread to re-post some of the info picked up here and there over this last year.

    Taken froma thread on RS246.com

    [ QUOTE ]
    I've done some research on the stock turbo, and found some compressor maps. Our k04 on the S3 Engine has a effecienty (works best) at 1.1 bar with around 138,000rpm compressor shaft speeds. It is 0.75 efficent @ 1.4bar/1.5bar but beyond this you reach spindle speeds of over 170,000rpm (very bad for turbo). At 1.4bar, the PR is about 2.5 (air exiting the compressor housing is 2.5x the pressure as entered)

    [/ QUOTE ]

    Here is the Compressor map
    [​IMG]

    Here is a picture of the blades
    [​IMG]

    and here is an image of how the turbo system works
    #14
  15. RAPS3
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    RAPS3 Active Member

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    Tried to upload a pic of how the turbo works but it wont /ubbthreads/images/graemlins/confused.gif

    #15
  16. mramage
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    mramage Member

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    [ QUOTE ]
    James M said:
    I'm confused, why is he saying with the K04 power output should not be more than 220hp?

    [/ QUOTE ]

    Yes, me to!

    First thing is I doubt Audi would be running it above the quoted figure, secondly, surey all those chipped cars should be blowing turbos after only a few thousand miles?

    Maybe I've missed something, but it doesn't make sense to me, only 5BHP between an 03 and an 04?
    /ubbthreads/images/graemlins/confused.gif
    #16
  17. peteA3tdi
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    peteA3tdi Member

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    i think they mean on the A3 1.8T not on the S3
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  18. mramage
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    mramage Member

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    [ QUOTE ]
    peteTDI said:
    i think they mean on the A3 1.8T not on the S3

    [/ QUOTE ]

    Ah, that would make a bit more sense. /ubbthreads/images/graemlins/smile.gif
    #18
  19. ANDYTQ
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    ANDYTQ Member

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    I'm in the middle of changing my turbo,always though i had a KO3S ,but have just found i actually have a KO3 026 fitted.Turbo i am fitting is a KO3S 052 model so should get a slight increase at top end.Fitting is a nightmare on a quattro no space at the lower rear of engine,my hands and arms are cut to ribbons.Removed old unit today,fitted uprated dog bone mount and will refit new unit tomorrow.But think of the money i will have saved by having a go myself.Cheers Andy
    #19
  20. Gambba
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    Gambba Active Member

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    [ QUOTE ]
    ANDYTQ said:
    always though i had a KO3S ,but have just found i actually have a KO3 026 fitted.

    [/ QUOTE ]

    But there is no K03S...so don't worry /ubbthreads/images/graemlins/lol.gif

    I know what you mean about the turbo area being a pain in the arse, but trust me if you do it enough times it becomes like second nature and you mangae to only feck up one set of knuckles instead of both!! /ubbthreads/images/graemlins/grin.gif I should know as I've replaced both top and bottom exhaust gaskets on the turbo, and now have the challange of removing a sheared stud from the bottom of the turbo!! /ubbthreads/images/graemlins/blush.gif
    #20
  21. Drill
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    Drill Member

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    Hey Andy, what's your engine code?? My 01 TQ has an ARX and now I'm wondering WTF I have for a turbo /ubbthreads/images/graemlins/confused.gif /ubbthreads/images/graemlins/crazy.gif

    Thx /ubbthreads/images/graemlins/grin.gif /ubbthreads/images/graemlins/beerchug.gif
    #21
  22. simont
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    simont Member

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    This is a very interesting thread - thanks Daniel for finding out some info on the K03 turbo differences.

    For what it's worth, I have a 2001 S4 and have recently had both turbos replaced. I got the old turbos back from the dealer and having just looked at them after reading this thread, the code is K03-016

    However, since having the new K03 turbos fitted by the dealer recently, there is definitely more turbo lag and I was wondering when getting the car back if there had been revisions since my original fitted turbos. As a result of the confirmation above, I take it now that the slightly larger compressor wheel is the cause of my bigger turbo lag???

    Unfortunately I didn't manage to get the dealer to note down the new K03 turbo coding, however the new turbos were made in November 2003...

    #22
  23. Shock_Xe
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    Shock_Xe New Member

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    Think people are confused which K04 he means.... He is reffering to the K04-01..... Not used in S3/TT applications The S3/TT225 uses the K04-20/k04-22/k04/23

    The K04-01 is a hybrid between k03 and k04, it was never used on Vag production vehicles! AMD/APR and the likes offer this as a conversion but it Does NOT require new manifold/lines etc, straight bolt on.... From what I was told by jabba It is essentially same as 0052/0053/0058 but has a smaller exhaust outlet and is more fragile. Hence why Jabba stopped this conversion and now use the 0052/0053/0058 (Bugger it ima Call it the K03s even tho they said it isnt, Easier!)

    Mike used mine and a mates car as a final decider wheather the K03s is a viable upgrade for K03 owners... I have a Ibiza Cupra and achieved 240-250bhp @ fly (250-260bhp din corrected) @ 1.5bar peak.

    I have been selling these particular turbos for 2mths or so now to Seat and UK-MkIV's and Skoda owners now with no probs....

    If anyone is interested drop me a line @ mike@am-motorsport.co.uk

    see www.am-motorsport.co.uk for info
    or www.seatcupra.net for threads.

    Prices are approx £225 used (low mileage) and £350 new. Andy Blunt on here just fitted one to his A3 which originally was a K03 turbo and done it without problems. Im sure he wil post soon.

    Anyone interested drop me a line

    Mike
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  24. ash_1909
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    ash_1909 New Member

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    right i need help i have replaced my turbo from a k03-052 to a k03-053 as it was only one available at the time in my budget but since doin so it seems like im down on power do i need a k03-052 on instead as im really struggling to find cause of power loss other than the diff in turbos as one being for a 180 and the other a 150bhp can anyone shed some light on this please
    #24
  25. cecilthesausage
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    cecilthesausage ...It's Never Finished...

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    Hahaha...[​IMG]
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  26. 16Klappe
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    16Klappe Princess Slayer

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    At least we can't say "you should have done a search" haha...
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  27. MEDEL514
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    MEDEL514 New Member

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    I have a K03-053 that needs a rebuild. Now after reading this thread, I'm starting to have doubts as to which route I want to take. Is the k03-053 turbine worth rebuilding or should I be looking into upgrading the turbine, or going K04-001 altogether?

    Yes, thread ressurection...thanks google!
    #27

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