A VW 16v camshaft study.

Discussion in '16-valve' started by Toyotec, Feb 9, 2008.

  1. chrismc Forum Junkie

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    I have since gone 2L on mine.

    Originally had an 051 ACE head running ABF cams- but have since gone to an 051 ABF head with KR cams (purely to get me mobile cheaply)

    The latter is noticeably better tho. Very pleasantly surprised.

    Some minor difference in the head castings maybe- but the KR cams make a 2L very torquey with no trade off in comparison that I noticed.

    I wont be using ABF cams again as a result

    Highlights to me that what might appear great on paper (more lift/similar duration) doesn't always translate to a real world faster setup. Theory only goes so far

    Many apologies for not being able to quantify my findings
     
  2. A.N. Other Banned after significant club disruption Dec 5th 2

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    The ABF head casting is the same as an ACE head, but the inlet cams are different (Edit: 051 101 vs 051 101A).

    KR cams in an ABF head are not a common modification.

    What aspect of the drive makes the KRs an inprovement? Has torque shifted downwards perhaps, giving a different feel on the butt dyno?
     
  3. chrismc Forum Junkie

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    I realise the casting is the same number but I believe the suffix is different- D versus F?

    In any case a quick visual comparison showed that the ABF head looked to have a better finish

    On the road the KR cams feel better everywhere- more low/mid range & top end urge.

    For a fast road setup this is certainly the best combination I have tried- if somewhat uncommon.

    Lacks a bit of top end revability compared to an 1800 for track work- but then I wonder if headwork would solve this. It's almost as if the ports are choking up at the top end- mixture throughput being greater per stroke on a larger capacity motor
     
  4. danster Forum Addict

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    Indeed, 051 103 373 and 051 103 373 D are different beasts, chamber shape and valve size. :thumbup:

    Posted purely to annoy and boost my post count rather than for information content. :lol:
     
  5. Toyotec

    Toyotec CGTI Committee - Happy helper at large Admin

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    The heads are the same mate and should have the casting number 051***373D. All later engines from as early as 92 had this head.


    I have driven and tested ABF engines with both cam sets, I beg to differ with your statement, which is a bit subjective without evidence. Maybe you have not benefitted from driving a well optimised ABF setup.
    The cam combination in an ABF code was not guessed and just chucked into the engine by engineers at VAG mind. Why would they waste money per engine unit if according to you the KR cam set is "better" in your estimation.
    The ABF cams are the best combination, in an ABF engine code when optimised for power and torque at WOT. Many posts on here and those which will be shared in the future already demonstrate this.
     
    Last edited: Jul 3, 2011
  6. Toyotec

    Toyotec CGTI Committee - Happy helper at large Admin

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    Which has significant influence on engine burn rate, all other things being equal.
     
  7. chrismc Forum Junkie

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    ACE head 373F from a 95M Audi 80 16v

    ABF head 373D from a post 94 ABF mk3 GTi 16v (exact age unknown)

    Have just physically checked.

    Have you tried the shortblock 9A/6A/ACE with ABF head & the different cams on kjet???

    I have not said KR are "better" per se- but (in conjunction with the 373D head) on my ACE block this setup feels stronger TO ME;) just an opinion:)
     
  8. Toyotec

    Toyotec CGTI Committee - Happy helper at large Admin

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    Not only have I tried, but I also had the benefit of a full mappable system when the swap was done.

    This was attempted on both a 9A and an ABF engine, both with SEMs.

    It, w/027 KR cams, would feel "stronger" than a base ACE engine w/ 101 051A inlet cam and assuming the state of tune is acceptable and consistent between both engine conditions.
     
  9. Toyotec

    Toyotec CGTI Committee - Happy helper at large Admin

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    Interesting in the origins of this suffix...
     
  10. chrismc Forum Junkie

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    The engine was never run as a base ACE in my car- my first setup used an ABF inlet cam to replace the oem ACE inlet in the 373F head.

    Now has KR cams in a 373D head & feels noticeably superior.

    Ignition timing & fuelling unaltered between head swaps
     
  11. Toyotec

    Toyotec CGTI Committee - Happy helper at large Admin

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    Well there is your issue!!

    Stay tuned stay optimised comes to mind.

    Of course this is assuming your perception of "superior" matches mine or my dyno plots and acceleration data for typical 16v engines.
     
  12. chrismc Forum Junkie

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    [:D]

    It would be hard to disagree given the latter setup is so much better.

    In terms of optimisation I'd be impressed if there was much left to be gained. Fuel pressure checked & adjusted combined with WUR mod, 10 degs of base ignition advance (any more and it pinks). This was the same before & after head swaps so effectively a constant and comparable state of tune
     
    Last edited: Jul 3, 2011
  13. vovcikGTI New Member

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    ABF cams the best :thumbup:
     
  14. ambrose89

    ambrose89 Forum Member

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    I have a 2lt mk2 16v golf with 051 133 373D (ACE,ABF) head from a 95 audi 80
    are the KR cams of the ACE ones best to have in this set up?
     
  15. ambrose89

    ambrose89 Forum Member

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    I have a 2lt mk2 16v golf with 051 133 373D (ACE,ABF) head from a 95 audi 80
    are the KR cams or the ACE ones best to have in this set up?
     
  16. Toyotec

    Toyotec CGTI Committee - Happy helper at large Admin

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    No. You need one ABF intake cam and that is it.
     
  17. ambrose89

    ambrose89 Forum Member

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    Thanks
     
    Last edited: Sep 2, 2013
  18. Toyotec

    Toyotec CGTI Committee - Happy helper at large Admin

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    No problem.
     
  19. vwbobby Forum Member

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    Sorry this is off the subject totally, but Toyotec, you have a email?
     
  20. Jon Olds Forum Junkie

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    excellent thread!
    Jon
     
    Toyotec likes this.

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