Results 1 to 9 of 9

Thread: knock retard starting to get confusing

  1. #1
    Potential Tuner
    Join Date
    Mar 2017
    Location
    Canandaigua NY
    Posts
    6

    knock retard starting to get confusing

    Sorry this is a pretty lengthy datalog. went for about a 20 mile drive. not sure why the VSS is reading so slow. at the constant 2200ish rpm I'm at 60-65mph. any time I give it any throttle the knock retard pegs to 8 degrees. do I have the timing advance too far and it's causing the retard to pull it back? motor is a 5.3 gen 3 with 4.8 pistons. An Edelbrock 2215 cam. stock heads, intake and throttle body. with a T56 magnum behind it.second run.hpl

  2. #2
    Advanced Tuner Obsolete489's Avatar
    Join Date
    Feb 2017
    Location
    Yankton, SD
    Posts
    299
    Is it throwing any codes?
    2000 K2500 - 489 CI Vortec w/ comp XE270 cam - 0411 swap and rear mount turbo
    1972 M35a2
    2011 LML Duramax

  3. #3
    Advanced Tuner
    Join Date
    Jan 2009
    Posts
    792
    That's the weirdest looking kr I've ever seen! That can't be real, if it is you're in big trouble. At the beginning of your log it's showing an almost constant knock up to 8 degrees also, that's damn near impossible. If it was actually knocking that bad you should be able to hear it. Are you sure you don't have a header banging on something? Either that or there's something really screwed up in the tune and that's actually burst knock or something.

    Oh I just noticed you said you had a 5.3 with 4.8 pistons. Duh. The pistons are so small they're flopping around in the bores and making a knocking noise.
    lol. jk.
    Check out my V8 Sky build video. It's pretty cool!...

    https://youtu.be/2q9BuzNRc3Q

    https://www.youtube.com/user/gmtech16450yz

  4. #4
    Advanced Tuner
    Join Date
    Nov 2015
    Location
    In a sandpit
    Posts
    444
    Thats seriously not normal! - post the tune!
    99 TA, Texas Speed LS376, PRC heads, 233/239 cam, Fast 92mm, 95mm TB, card style MAF, Tick TR6060, Strange 4.11 12 bolt axle & clutchpack diff, Strano springs/dampers, Vette 18" wheels, Vette disks, CTS-V calipers, 16lb flywheel, long tube headers, no cats.

  5. #5
    Tuner in Training
    Join Date
    Sep 2015
    Posts
    25
    Have you checked for codes? You may have a knock sensor that's bad. Mine just did this a couple weeks ago and one of the two was bad. Is the motor a transplant or is it in the stock vehicle? Headers? No clearance issues?

  6. #6
    Potential Tuner
    Join Date
    Mar 2017
    Location
    Canandaigua NY
    Posts
    6
    Thanks for the replies, I haven't had much time to get on here lately. motor is in a g-body. hooker manifolds. Not really any clearance problems other than the trans rubs on the tunnel sometimes. Not much of an exhaust on the car so not sure if that's throwing it off or not. basically 2.5" pipe to two glasspacks dumped to each side of the car. doesn't reach the rear axle. I will post the tune when I get home from work in like 4 hours

  7. #7
    Potential Tuner
    Join Date
    Mar 2017
    Location
    Canandaigua NY
    Posts
    6
    here you guys go. thank you!
    Attached Files Attached Files

  8. #8
    Advanced Tuner
    Join Date
    Nov 2015
    Location
    In a sandpit
    Posts
    444
    VE doesn't look very sensible (not cause of knock 'tho). Spark also a bit odd but not too bad. Knock sensor table ( knock sensor level > vs rpm vs cyl) is waaaayy different than a normal LS1, all the values there are around half of a 5.7L LS1??? This would make it MUCH more sensitive to knock... it <might> be normal for 5.3, I don't know, suggest you have a look at a standard file..

    Oh and the high/low octane tables are the same, so it won't be compensating very well...
    Last edited by dermotw; 03-28-2017 at 03:12 PM.
    99 TA, Texas Speed LS376, PRC heads, 233/239 cam, Fast 92mm, 95mm TB, card style MAF, Tick TR6060, Strange 4.11 12 bolt axle & clutchpack diff, Strano springs/dampers, Vette 18" wheels, Vette disks, CTS-V calipers, 16lb flywheel, long tube headers, no cats.

  9. #9
    Senior Tuner
    Join Date
    May 2016
    Posts
    1,134
    More sensitive knock settings than stock 5.3 Gen 3 truck reads I have. Try something like 15 below 2k tapering down to 10 or 11 by redline and see if it helps. Be aware that you are making the sensor less sensitive by doing this though.