Results 1 to 6 of 6

Thread: 2011 CTS-V hitting rev limiter repeatedly

  1. #1
    Tuner
    Join Date
    Feb 2008
    Location
    Sikeston, MO
    Posts
    173

    2011 CTS-V hitting rev limiter repeatedly

    Hello all, worked on a 2011 CTS-V tonight. I spent all night working on the trans tuning. The car has a built 6L90E with parts from transmissioncenter.net with their pressure tuning. I will contact them Monday if no one has any ideas on this. Stock converter. We rebuilt it last year after repeated 6-second 1/8th mile passes when it started slipping. The owner sent the tune to them, they changed it for their parts, and all I have modified until tonight has been the shift speed/rpm stuff. The car did flawless last year, and we ran several 6.8 passes.

    Now, we put in an LSX376 crate engine. The car is roughly 900 HP now. It will not shift out of first without hitting the rev limiter to save its life. It has 18" drag radials now instead of the 19" ones, but I compensated for that. I have been using the spreadsheet to adjust, but even lowering it down to 1500 RPM and 5 mph, it will not shift. We started out much higher, but just to get a response continued lowering it to no avail. We set the rev limiter to 7000 RPM, and it still hit it. The car runs through the gears in the burn out, getting into 4th even. There is no slip and a nice linear pull on the graphs, it just does not shift. 2nd will occassionally go into the rev limiter, but it was cooling down and the car was making more power, so I was having to pre-empt the shift more.

    I logged gear, it shows the gear changes at the commanded mph, but the indicator on the dash shows when it actually shifts, which is what the data log shows).

    Any advice is greatly appreciated. I've been able to work through most issues, but this one I couldn't get a response regardless of what I tried.
    Attached Files Attached Files

  2. #2
    Advanced Tuner
    Join Date
    Jun 2011
    Location
    Montreal, Canada
    Posts
    758
    Assuming the traction control is off (it being activated could prevent shifts) it sounds like a mechanical problem. You mention it started slipping . Might be too late for tune changes after that.
    2007 Corvette C6 Vert. A6
    LME LS402, Pat G custom cam, ATI 10% OD Damper
    Circle D triple disc 2600, 3.42 Diff
    YSI, 3.0 pulley, ID 1000's
    Alky Control Meth,
    ARH 1 7/8 headers,
    1009 RWHP @ 7000, 817 RWT @ 6000

  3. #3
    Tuner
    Join Date
    Feb 2008
    Location
    Sikeston, MO
    Posts
    173
    The slippage was before the rebuild. It is solid as a rock now.

  4. #4
    Advanced Tuner
    Join Date
    Jun 2011
    Location
    Montreal, Canada
    Posts
    758
    Quote Originally Posted by GregRexAdams View Post
    The slippage was before the rebuild. It is solid as a rock now.
    Ok, didnt quite get that at first. Those super high pressures and short shift times would not do well in a stock tranny. i guess they know what they are talking about for their parts but maybe try a bit longer shift times. These trannys need some time to shift.

    Let us know what the outcome of this is please.
    2007 Corvette C6 Vert. A6
    LME LS402, Pat G custom cam, ATI 10% OD Damper
    Circle D triple disc 2600, 3.42 Diff
    YSI, 3.0 pulley, ID 1000's
    Alky Control Meth,
    ARH 1 7/8 headers,
    1009 RWHP @ 7000, 817 RWT @ 6000

  5. #5
    Tuner
    Join Date
    Feb 2008
    Location
    Sikeston, MO
    Posts
    173
    Ok, adjusted shift times to no avail, tried turning torque management back on to no avail, and tried increasing desired torque to no avail. They all helped the later gears but did nothing for first.

    At this point, we suspect a slosh issue, where the trans pickup is not getting any fluid until it hits the rev limiter. In the .6 the car is in the rev-limiter, it gains only 2 mph, so it would level out. We are checking levels, fluid type, etc today and making sure we didn't miss anything. We will probably over fill the trans to eliminate the possibility.

  6. #6
    Senior Tuner DSteck's Avatar
    Join Date
    Mar 2008
    Location
    St. Louis, MO
    Posts
    4,856
    I haven't had a chance to open the tune yet. Were the oncoming and offgoing volumes modified from stock?

    DSX Tuning - Authorized HP Tuners Dealer
    http://www.dsxtuning.com
    http://www.facebook.com/dsx.tuning
    Just say no to bull s***.
    IF YOU WANT HELP, POST A FILE!