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Thread: Trans Am 455

  1. #1

    Default Trans Am 455

    Running Brawler 850. Cam is 274° in. I can set idle on primaries 1 1/2 turns out, but directly I try to adjust secondaries it runs real rich. So I have to leave secondaries screwed in. I have 12 inHg on my vacuum gauge, which is best I can get. That's at 750 idle.

  2. #2
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    What are the exact camshaft specs, and the rest of the engine? Turn all screws in until lightly seated, then screw them all out 3/4 turn, then start trimming from there. Gary
    Regards, Gary

  3. #3

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    Thanks Gary. I've since read on the net to try 3/4 on screws and have sorted still have a little stumble at about 1500 RPM on acceleration. Cam specs: Centerline 114°, 274° ADV duration, duration @ .050" 226°, LSA 110°. Thanks, Bob

  4. #4
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    Hi Bob. I would think that cam should produce better vacuum, 274° ADV, 226° @ .050".
    Did you build the engine?
    What intake manifold you are running?
    How much timing at idle?
    Auto or manual transmission? Gary
    Regards, Gary

  5. #5

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    Just had the heads ported. I'm running a single-plane manifold, which has been port matched to heads. 16° at idle. Manual transmission.

  6. #6
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    If the carb is running more evenly now, you need to get some miles on it, and add a wideband A/F ratio gauge to see what's happening. Gary
    Regards, Gary

  7. #7

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    Thanks Gary. I've increased idle to 850 and I've increased vacuum to 18 inHg.

  8. #8
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    That sounds a bit more promising. Now how does it go on the road? Gary
    Regards, Gary

  9. #9

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    Went for a drive couple of hours ago, seems okay. From 2000 RPM, it really gets up & goes. Waiting for next drag meeting was doing flat 14, so here's hoping mid 13. I just fitted 6 piston Wilwood calipers and slotted 12" rotors, so hopefully it will stop. Thanks, Bob.

  10. #10
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    You'll need to look at the IFRs for the 1500 RPM issue. Gary
    Regards, Gary

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