Results 1 to 3 of 3

Thread: 6L80E Lock-up MPH for 1/4 mile

  1. #1
    Tuner in Training
    Join Date
    Aug 2019
    Posts
    14

    Question 6L80E Lock-up MPH for 1/4 mile

    I've been doing some setup changes on my TCM tune and am curious where most folks like to see their converter lockup on a 1/4 mile pass. I'm running a custom CircleD 245mm converter, stalls right around 4400 RPM in my C7. WOT shifting at 6800 RPM, I currently have it locking up at 99 MPH in 3rd, but wondering if it should be sooner. I'm hitting 4th gear @ 121 MPH...should I keep it locked up for all of 4th as well?

  2. #2
    Senior Tuner
    Join Date
    Jun 2004
    Location
    405
    Posts
    2,287
    You need to do a dyno pull with the converter unlocked and one with the converter locked. Then overlay the two HP graphs plotted vs mph. The MPH point there the graphs cross is the MPH to lock the converter. It is also said that if you run quicker times with a locked converter vs an unlocked one that you have the wrong converter for the vehicle.

  3. #3
    What time does it run? and at what MPH?, I have been trying to answer the same question about locking but cant get a straight answer, seems trial and error is the only way to find out.
    Is it a single or triple disc converter? I've tried lock my converter in 4th but it was unable to hold the torque.
    I have been looking to upgrade to a Circle D triple disc, dont suppose you'd have some quarter mile logs with converter slip you'd be willing to post? Interest to compare a Circle D converter to my current set up.
    2010 GXP Maloo ute, LS3, 6L80E.
    MM heads, 240/252@50 solid cam, 12.75:1 compression, 4500 Dominator converter, 3.46 rears.
    Shooting for 10s eventually.