Drivetrain Vibration Questions

Discussion in 'Troubleshooting & Diagnosis' started by Glava, Nov 15, 2021.

  1. rocket dawg

    rocket dawg Veteran Member

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    While chasing my vibration, I did a trans mount. It didnt fix my problem ( tires were my problem) but the mount was 100% shot and needed to be replaced. Fairly easy job, too. Car is a 79 and this was done about 8 years ago.
     
  2. G72Zed

    G72Zed Veteran Member

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    That's a pretty good mph with the tires of yesteryear, what gear was in it, 3.73's I would assume with a 26.5" tall tire, if so that's 7,100 rpm @ 150 mph, must of been a rush that's for sure.

    I hit 140 mph last time out a few weeks ago, smooth as heck, but only turning 5,200 rpm in 5th, right at the start of the tq peak, so I had the rest of the power band to use, but tires are done, so that was it for me LOL. It was very smooth.
     
  3. COPO

    COPO Veteran Member Lifetime Gold Member

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    ^With 3.73, I didn’t have time to look at the tach at that speed, my eyes were peeled on the 2 lane road. But at that speed my ignition shutdown and started again once I let up.

    With brand new Firestone F60 Wide Ovals. Cost $67 each in 1975.
    BB8588CF-8244-4701-8674-D9DDF9BE95E7.png
     
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  4. BonzoHansen

    BonzoHansen Administrator Lifetime Gold Member

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    I find my car likes to start lifting at 125 or so, the front end starts feeling light
     
  5. biker

    biker Veteran Member

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    Lowering the front end a bit seems to eliminate that. Short stiff springs and good shocks stop it from lifting over whoopdy-style road contours that you dont notice at lower speeds. I like to wind mine up to 150+ (briefly) once in a while. The aero at those speeds seems good, my worries now at those speeds are steering play and twitchiness, and tires. Time for a good new box. Tires are new, but not rated for those speeds.
     
  6. BonzoHansen

    BonzoHansen Administrator Lifetime Gold Member

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    I've got all that lol.
     
  7. MChamp

    MChamp Veteran Member

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    tunnel visionnn is koool
     
  8. G72Zed

    G72Zed Veteran Member

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    Oh, ok, then I can see that can get a little scary Bonzo.


    Good points biker, a pair of adjustable shocks can really help out in that area, on both ends. Double even better. I set mine on 8-12 compression and 12-13 rebound, digressive valving as well.



    How much toe change on lift vs baseline alignment settings? Added caster helps as well, as well as a good box and pump combo that pulls assist on higher rpms.
     
  9. mallard

    mallard Veteran Member

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    It's been YEARS since I dared take a car up to those kinds of speeds. Driving back to the city from the drag strip one Sunday in '74 I had a little "go" with a Mach 1 mustang on the highway. I had a '69 Grand Prix 428 at the time. From 60 to 100, he had me by about 1.5 car lengths, but from 100 on, I caught up and was about 3/4 car length ahead by 134 mph (this was before metric in Canada) and, like a previous posted said, the car was lifting in the front so I backed off. I've never had a car up to that kind of speed since.
     
  10. BonzoHansen

    BonzoHansen Administrator Lifetime Gold Member

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    6° caster, toe 0°. I have a decent 12.7:1 3rd gen ws6 16" wheel box, which is ok, better than stock.

    I might be able to talk myself into upgrading from the bilsteins. :)

    Don't get me wrong, it's not like crazy scary. But I can feel it. Adding the factory front spoiler helped a bit.

    I don't really care that much lol
     

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