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Thread: intake and exhaust cam timing whihc is advance/retard?

  1. #1
    Senior Tuner
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    intake and exhaust cam timing whihc is advance/retard?

    Im used to Gen4-5 V8 stuff where intake cam numbers falling mean the cam is retarding, but on ATSV with the exhaust cam the number fall as rpm goes up also, and Id think that the exhaust cam would be advancing at high rpm??? Less time to blow cylinder down and your not going to hurt the power stroke at 5000rpm opening it too early Is lower advance or retard on the exhaust cam?
    Factory Stock 97 SS M6 13.51 @ 104.3 mph
    Stock Longblock LS1 w/ 233/238 P.S.I. Cam
    10.81 @ 126.9 Full interior, six speed on 275 radials, a decade ago

    '99 TA trunk mounted 76mm 6 Liter
    9.0s in '09 @ 153 MPH

    Turbo 5.3 Volvo 740 Wagon
    32psi and still winding out 5th on the highway somewhere

  2. #2
    What engine/ECU is this? For the LFX (E39A) the intake cams can only be advanced, and a bigger number means more advance; the exhaust cams can only be retarded, and a bigger number means more retard. I imagine other V6's/ECU's around this time are similar. The factory tune for the V6 Camaro has the exhaust cam advancing (numbers get smaller) as RPM's increase (see post #10 https://forum.hptuners.com/showthrea...tor-Dwell-Time).

  3. #3
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    ATSV E92A, but id assume they kept strategy consistent throughout?

    Yes like Gen4/5 v8 intake numbers higher is advancing cam, the home position 0 is full retard.

    Ahhh so yes smaller number is advancing exh cam not retarding just like I though
    Factory Stock 97 SS M6 13.51 @ 104.3 mph
    Stock Longblock LS1 w/ 233/238 P.S.I. Cam
    10.81 @ 126.9 Full interior, six speed on 275 radials, a decade ago

    '99 TA trunk mounted 76mm 6 Liter
    9.0s in '09 @ 153 MPH

    Turbo 5.3 Volvo 740 Wagon
    32psi and still winding out 5th on the highway somewhere