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Thread: Whats the "noisest" forged motor you've seen?

  1. #21
    Senior Tuner
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    So I am back to tracing something hitting or rubbing, have confirmations from two different folks running 2" primary headers, both had them rubbing on the passenger frame rails with false knock under heavy loads. I am going to do some more massaging and also order a set of polyurethane motor mounts to help lessen the engine movement.

  2. #22
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    Little update, just for testing, I set the thresholds to about 4.25 just for a test, logged zero knock but the car breaks up fairly badly, popping and not accelerating much at all once boost is above 4-5psi. Even at 4-5psi i can feel what feels like cylinder(s) giving out and acceleration is fairly poor.

    So this is pointing more towards ignition issues, such as blowout or bad plugs. They are brand new Brisk 12S gapped at 0.028. Before that were brand new (less than 100 miles) Champion iridiums (3 steps colder) gapped at 0.028.

  3. #23
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    I will post up a log, but was logging right about 0.80 lambda at 9-10 degrees of timing when it breaks up.

  4. #24
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    How is the engine ground?

  5. #25
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    Quote Originally Posted by spoolboy View Post
    How is the engine ground?
    I have checked over everything, all seem to be in order, but that's another good check.

  6. #26
    Hi ,all following your thread,
    I have same pistons in my boosted GC srt8. 2016 , Have had a lot of problems particularly with cold engine ,where the piston rattle would be enough to log short and long term knock and then retard timing,
    I found that piston knock was ok after 90 deg c oil temp was reached , however it had logged enough long term knock which then made it run badly until I stopped the car waited a few mins then restarted and as it was now hot ran fine
    I had HP add temp thresholds to KNK sensor Short term and Long term. enable , This has pretty much got me thru the cold / warm up problem , I also upped the KNK scaling a little
    Mine runs a F1A PC. peaks at about 13 psi. max timing 6 deg wot
    .I had a set of headers but ended up running the stk exhaust after the aftermarket cats died ,, can't say really noticed any power change but its much quieter inside ,

  7. #27
    Another thought based around what I have experienced
    Once I had an issue when it was dropping cyls under boost I configured my logger to see which cyls and it was alternately dropping about 4 of them , It turned out that as I had been playing around with the power enrichment threshold trying to get more enrichment , I had not changed the wot on TQ management so it was dropping cyl because of TQ management, currently I have it about 2.3 V , I would like it lower but it stumbles when you go lower