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Thread: TPS Voltage - 3.8v vs 5.0v at WOT?

  1. #1
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    TPS Voltage - 3.8v vs 5.0v at WOT?

    Did some testing the other day...noticed under WOT the TPS sensor reads 3.8v in my logs, we visibly looked at the throttle body and it appeared WOT. We then turned off the car, but stayed connected, ignition on. We by hand opened the throttle body and it went to EXACTLY 5.0 volts when it was wide open in the scanner.

    How is this possible? Is there some scalar only applied to the channel when the vehicle is actually running? Or is it that from 3.8v to 5.0volts it isn't actually visible?

    This goes to the same issue I have always had that the standard TPS% channel in the scanner never goes over 87-88% since it assumes 5.0volts is WOT when in reality it is 3.8volts....or is it?

  2. #2
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    it probably follows the same concept of the GM WOT. Since 88% or so is already WOT, taking the blad and shaft cross sectional thickness into consideration, theres no point in going any further. Its easier for the ECU to correct blade position from 88% than from 100% isn't it?
    2018 Camaro SS, Maggie 2650, 103 TB, Big Gulp, E85

  3. #3
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    Yes, that makes sense, except when you are running a 5"x3" throttle body with a completely non stock blade/shaft thickness.

    I haven't been able to find where to control how far it opens, do you know how? Tried the pedal follower with no luck.

  4. #4
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    what are you trying to do? open the blade further at WOT?
    2018 Camaro SS, Maggie 2650, 103 TB, Big Gulp, E85

  5. #5
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    Quote Originally Posted by GPGTP View Post
    what are you trying to do? open the blade further at WOT?
    Yes, based on the blade being so much larger/longer, at the angle of 88% its actually slightly lower than the thickness of the rod, so it could use slightly more rotation.

  6. #6
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    Quote Originally Posted by 06300CSRT8 View Post
    Yes, based on the blade being so much larger/longer, at the angle of 88% its actually slightly lower than the thickness of the rod, so it could use slightly more rotation.
    post your tune but what year is your car and what mods? The only table i can see on this 07 is Engine->airflow->electronic throttle->throttle max. Otherwise I doubt its possible with the tables. I would have to see a pic of the throttle body opening to have any idea how much its actually restricting.
    2018 Camaro SS, Maggie 2650, 103 TB, Big Gulp, E85

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  8. #8
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    Did you try changing your Peddle WOT to 5.0v ? Do you have to change the Peddle % Request & Expected and the Desired Throttle stuff to 5.0 also? All of those tables are around the 4 volts or lower.