Enter your username:
Do you want to login or register?
  • Forgot your password?

    Login / Register



    Page 3 of 3 FirstFirst 1 2 3
    Results 41 to 47 of 47
    1. #41
      Join Date
      Apr 2013
      Posts
      87
      Country Flag: Canada
      Quote Originally Posted by 68Malibu383 View Post
      Hey Bandit, nice Nova and thanks for posting the info and vid. I have the same problems as the OP and I've had three different master cylinders of different bores on the car. I switched to manual because my engine only has 11" of vacuum at idle and it did not work great with the factory 11" booster (a little more to that).

      I have the same C6 and LS1 combo so I'd assume if I added the dual 9" booster, I'd have similar performance (currently have 15/16 master). Do you know how much vacuum you have at idle and do you have issues with the booster not having enough vacuum with short repetitive heavy braking (ie autocrossing)?
      For what its worth if this modification doesn't change my braking performance I am going to go with a new front brake kit including spindles and bearings.

      I am 99% certain that my rear brakes are fine considering i am using the LS1 f-body backing plate against the diff using shim stock to space out the disc between the caliper (so it should be as square as possible).
      1970 Chevelle Malibu 350 "70 Hell"
      - UMI - Kore3 - LS1 4 wheel discs - Budnik

    2. #42
      Join Date
      Nov 2010
      Location
      Ventura County CA
      Posts
      556
      Country Flag: United States
      Quote Originally Posted by 68Malibu383 View Post
      Hey Bandit, nice Nova and thanks for posting the info and vid. I have the same problems as the OP and I've had three different master cylinders of different bores on the car. I switched to manual because my engine only has 11" of vacuum at idle and it did not work great with the factory 11" booster (a little more to that).

      I have the same C6 and LS1 combo so I'd assume if I added the dual 9" booster, I'd have similar performance (currently have 15/16 master). Do you know how much vacuum you have at idle and do you have issues with the booster not having enough vacuum with short repetitive heavy braking (ie autocrossing)?
      I am using a dual 9" booster from Tuff Stuff. The engine makes about 11" vacuum at 800rpm idle cold and improves to around 13" warm. I can tell the difference in braking when the engine hasn't warmed up yet; it just feels a little off until the vacuum increases. I suspect I'm right at the threshold of having enough vacuum, but it does behave fine when its warmed up. I could probably bump up the idle but that's a trip back to the tuner for me and not worth it at this point. I have not yet driven it at autocross with this brake setup, so I'm not sure how it will do with lots of repetitive hard braking. Around town it feels similar to my original disc/drum system when it was in good working order. I don't run a vacuum accumulator/can or anything at this point.
      Clint - '70 Nova "restomod" cruiser & autocross family car

    3. #43
      Join Date
      Nov 2010
      Location
      Ventura County CA
      Posts
      556
      Country Flag: United States
      Quote Originally Posted by 70chevellemalibu View Post
      i tried the proportioning valve both directions and the brakes dont lock up in the front (never really tried in the back).
      How is your proportioning valve plumbed?

      Typically the prop valve is installed in the rear line, not the front, so the valve should have no effect on your ability to lock the fronts. If your master is sized and plumbed properly to the front you should be able to lock the front tires with very heavy pedal pressure.

      I'll admit I haven't read the whole thread so I'll go back and see what I can learn from what you've already written.
      Clint - '70 Nova "restomod" cruiser & autocross family car

    4. #44
      Join Date
      Nov 2010
      Location
      Ventura County CA
      Posts
      556
      Country Flag: United States
      70chevellemalibu what size booster are you running?
      Clint - '70 Nova "restomod" cruiser & autocross family car

    5. #45
      Join Date
      Apr 2013
      Posts
      87
      Country Flag: Canada
      Quote Originally Posted by TheBandit View Post
      70chevellemalibu what size booster are you running?
      11”, recommended and confirmed with Tobin.

      i honestly feel the problem is with the alignment or lack of alignment with the pads and rotor. I have 2 summer with the car and moderate braking, enough that I developed and pattern on my rotors that clearly showed wear versus no wear meaning I’m not getting full pad contact.

      After all this realignment I’m hoping I can step on the brake and it will send me through the front window lol.

      the snow is all melted so as long and it doesn’t snow again this week I’ll be able to go down the road and get in a test run.
      1970 Chevelle Malibu 350 "70 Hell"
      - UMI - Kore3 - LS1 4 wheel discs - Budnik

    6. #46
      Join Date
      Nov 2010
      Location
      Ventura County CA
      Posts
      556
      Country Flag: United States
      Unless both calipers are having issues, you should still be able to lock up the other tire. Does your pedal hit the floor before you get full brake pressure? Maybe something else is going on.
      Clint - '70 Nova "restomod" cruiser & autocross family car

    7. #47
      Join Date
      Apr 2013
      Posts
      87
      Country Flag: Canada
      Finally got a chance to get a few miles on the car after re centering the caliper and changing the pads to a semi - metallic; brakes are better and you can tell the surface area wear on the rotor has increased.

      I still cant get the car to lock up the front brakes, when i find time i am going to sit in an empty parking lot and play with the adjustable prop valve to get the best feel/performance.

      Thanks.

      1970 Chevelle Malibu 350 "70 Hell"
      - UMI - Kore3 - LS1 4 wheel discs - Budnik


    Page 3 of 3 FirstFirst 1 2 3




    Advertise on Pro-Touring.com