poor performance after cam upgrade

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  • N.B
    N.B
    6 years ago
    hi guys,
    i recently had a set of andrews 57h cams installed into my 2016 fxdb along with pushrods and lifters. the bike was dyno tuned here in brisbane, and after a few hundred km's of getting used to the setup, the bike's performance and ride-ability in the lower rpms is shocking. at around 1800 to 2300rpm (1st or 2nd gear) the bike convulses and bucks terribly. i don't make a habit of riding in this range alot, but it can't be helped in slow peak hour traffic where i can't lane filter. one minute the bike is going to stall, next minute it's surging...all while holding the throttle steady. in higher rpm's of 3000+ the bike runs great, and pulls hard as expected with these cams. but even when moving off the line the bike really bogs down and feels like it's going to stall...almost like i'm taking off in 3rd. i had another mechanic ride the bike and he said he's never felt low down bucking like that before.

    the tuner believes it's the exhaust causing the issues (two brothers 2 into 1) and of course after writing to two brothers they blame the cam choice. the tuner told me that the bike had to be tuned really lean, with a bunch of timing adjustments just to get it to run decently. i trust him as a tuner, and feel that he's doing the right thing by me and the bike. 

    the bike feels as though the performance is getting worse and it's going back to the tuner for a once over next week. i haven't come across any bikes with this cam and pipe combo, but have any of you guys had any issues similar to this after a cam upgrade?

    a summary of what's been done and tested:
    - installed andrews 57h cams
    - s&s pushrods
    - feuling lifters
    - dyno tuned with powervision
    - new spark plugs
    - new tps sensor
    - new exhaust gaskets 
    - compression test - 175psi in both cylinders

    i know that the 57h cams are a mid range cam, but surely it shouldn't be such a turd low down. hopefully someone here might have some insight or experience.


  • Undercover
    Undercover
    6 years ago
    I've got Andrews 57H cams the usual after market Air Filter and a Supertrapp 2-1, the bike runs great thanks to a good tune. 
    Ring and speak to other tuners and ask how they would set up the bike with CAMS/Exhaust etc. it's always good to get a second opinion.
  • speedzter
    speedzter
    6 years ago
    I wouldn't really call the TW57 a mid range cam, more a low-mid , it's fairly mild.
    It would like a tick more compression than stock, but shouldn't cause the issues you are having.
    Not really familiar with the TBR 2-1, but it shouldn't cause any problems either.
    Have you done a compression check ?

    Something is screwed, and it's likely not the combination of parts.
  • N.B
    N.B
    6 years ago
    hey hilly, any idea on what could be causing the issues, or anything to try? the bike ran great prior to cams, so i can only assume it's related to the new parts and tune. the bike was tuned by the same guy previously at 85hp/103tq...post upgrade we got 92/100. i'm not looking to swap anything out just yet, but he does want to try an exhaust swap and do a power run to test out his theory. 
    the gremlin that really get me is...the bike is running really lean, yet it smells really rich and i've gone through half a tank on two return trips to work (20km each way). i know cams can affect consumption, but surely not like that.
  • robots
    robots
    6 years ago
    pull the plugs if you using that much fuel you see it or if running that lean you will see white as plugs
    compare your stock map to tuned map, try a map from powervision
  • Arron
    Arron
    6 years ago
    Have 57H cams in my 2013 street bob that i fitted and tuned myself (TTS), was running stock exhaust and aftermarket air cleaner then tried S&S slipons then swapped to stock air cleaner and exhaust .
    The valve stem guides had to be replaced and the intake was fairly caked up with oil/carbon , did the spanner work myself and had the machine work done at Southside in Perth and even with my lack of tuning skills i was always happy with the cams.
    I will say that i haven't ridden any modded Harleys so don't have anything to compare it to.
     It can feel dead off the line in hot weather but that's it.

    P.S Fuel usage has always been near enough the same as stock with the cams.
  • srd0060
    srd0060
    6 years ago
    Did he use adjustable pushrods?
  • N.B
    N.B
    6 years ago
    the valve train noise has definitely gone up, i heard it's common after new pushrods and lifters and thought not much of it. but i'll look into it. i'll check for intake leaks tomorrow to rule that out. thanks hilly!
  • N.B
    N.B
    6 years ago
    ok so i've spent a couple of hours in the garage today and checked a few things over:

    - pushrods seem to be installed correctly, they spin freely between my fingers with no sideways movement when on the base of the cam lobes
    - there is no intake leak on either cylinder - sprayed wd40 around the manifold while idling, revs didn't change.
    - there is no exhaust leaks - held an incense stick around both exhaust ports and the smoke wasn't blown around by a leak
    - plugs are gapped correctly - but are white/lean.

    the bike started a bit stronger when back together, but the bucking/surging etc. was obviously still there. i decided i'd try to autotune it, and rode around for 40 mins in the rev range that's been giving me trouble. took a look at the autotune results and it made the bike even leaner in the 0,2,5% columns of the ve tables. 

    maybe the oem cams should go back in until i can find a better marry/combo of parts....or an exorcism.
  • Baloffski
    Baloffski
    6 years ago
    Sorry to barge in, but curious. H and H did ya pickup, and what was the issue?  Thanks all..
  • N.B
    N.B
    6 years ago
    for anyone interested:

  • robots
    robots
    6 years ago
    add 10 points to the VE tables 1000-2000rpms 
  • robots
    robots
    6 years ago
    Trust all those dyno sheets at that site? 
    Most corrupted place getting around
  • robots
    robots
    6 years ago
    how it go
  • robots
    robots
    6 years ago
    Thats good
  • srd0060
    srd0060
    6 years ago
    Suspence is killing me....
  • srd0060
    srd0060
    6 years ago
    So what’s the out come???
  • N.B
    N.B
    6 years ago
    i haven't picked up the bike yet, so i won't really know until i ride it. but i got a call from the tuner saying that he's sorted it out. 
    initially they were going to do an exhaust swap to rule out my 2into1, but went with a compression test first up. he only got 160ish psi in both cylinders, which set off alarm bells. they pulled the bike down and found that they had installed the cams off by a tooth, throwing the timing all out of wack. everything was redone, and re-tuned, and the bike has gone from 92hp/100tq to 98hp/111tq with 200psi in both cylinders.

    like i said, i won't know until i pick it up and ride it, but over the phone at least it sounds like it's sorted. :)
  • markwoumla
    markwoumla
    6 years ago
    The old cam chain out by a tooth trick !!!!!!  Good to see they sorted things out for you ..... The  figures on the final tune seem to be were they should be with the 57s..... The figures  did seem a bit low on your original runs, even , (at the time), thinking the exhaust was holding it back.....  Would be interesting to see the dyno chart, and were   the power comes on with 57s etc, with no other work other  than a cam swap .....  And of course your butt seat dyno opinion..   Cheers ....... 
  • srd0060
    srd0060
    6 years ago
    Well that’s good to hear, all you need to do is get out and enjoy it.
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