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Thread: Jet DST LT4 Vette Headers and Cold Air?

  1. #1
    Carb and Points!
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    Jet DST LT4 Vette Headers and Cold Air?

    Hi all I am new to the Forum and I have a newbee question!
    So I have an LT4 Vette with 1 3/4" ARH headers/cats, and Cold Air. I just bought a used JET DST and am familiar with tuning terms for the most part. I have already programmed my cooling fans to turn on faster and eliminated my CAGS (JET calls it CARS for whatever reason).
    My car runs great no issues but I am wondering if more HP could be gained by tuning the fuel and spark? If there is not much to be gained then I won't bother tuning as the car does run great.
    If there are decent gains by tuning then should I tune at an RPM level around 4000 RPM and up? I have a scan tool that will take readings and let me upload to my computer. I am thinking of making a few WOT runs to see what it looks like and then start adjusting but I am new to this so any suggestions would be appreciated

  2. #2
    Carb and Points!
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    What is CAGS/CARS? I also just started using DST and trying to learn the terms. Thx

  3. #3
    Carb and Points!
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    Quote Originally Posted by TonyT1996 View Post
    What is CAGS/CARS? I also just started using DST and trying to learn the terms. Thx
    CAGS is Computer Aided Gear Selecton (it is when you are driving slow and the computer engages a solenoid inside the manual transmission to force a 1st to 4th shift). JET DST calls this CARS and I have no idea why, I think they misspelled CAGS.
    Good luck with your tuning there is certainly not much out there for help on the LT4 engines. I stopped playing after turning off the CAGS, lowering my electric fan turn on temperature and giving a slight timing boost in the upper RPMs.
    The car doesn't ping and runs great but it is trial and error and I was extremely conservative with my adjustment (probably no gain at all for horsepower but the engine runs nicely).
    Last edited by grandspt; 4 Weeks Ago at 04:25 PM.

  4. #4
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    CARS = Computer Aided Ratio Selection. Engineering term.
    CAGS = Computer Aided Gear Selection. Marketing term.

  5. #5
    Carb and Points!
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    Quote Originally Posted by 1project2many View Post
    CARS = Computer Aided Ratio Selection. Engineering term.
    CAGS = Computer Aided Gear Selection. Marketing term.
    So DST considers the skip shift a gear ratio selection hence CARS. Makes sense but it would have been easier for me if they called it CAGS. :-) It took me a while to figure out that CARS would disable the skip shift.

  6. #6
    Carb and Points!
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    So I appreciate the dictionary meaning of the CARS do you have any tuning tips?
    Last edited by grandspt; 4 Weeks Ago at 04:30 PM.

  7. #7
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    Last time I tuned an LT4 was in... umm... 2001 or 2002? Step 1 was to remove Hypertech tuning. After that I worked on reducing delivered fuel at WOT. That helped improve power level but I had a chassis dyno available so I could make changes in increments. The next step would have been looking at the WOT enable parameters to see if they seemed appropriate for the owner's style of driving. I seem to remember that I liked much of the LT4 tune as was and without having time to do some on-street driving I wasn't going to make too many changes.

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