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Old 09-04-2012, 05:04 PM   #1
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Default Brake drag...what a drag

Here is the issue. Prior to going out on track if I spin a front tire, it will rotate approx 8-10 full revolutions, immediately after a race the front will spin approx 2 revolutions. This is a massive amount of drag, meaning more brake temp, not to mention more heat in the hubs, and less net horsepower.

I have to run stock calipers and rotors, pads are open and ducting is allowed. I plan on having the ducting in place within the week, scca runoffs are just a few weeks off. Has anyone else run into this issue, and if you have, what have you done, if anything, to remedy the situation?

My current setup: Tilton twin masters with bias bar, both masters are 5/8", 1.6 calipers and rotors, hawk blue pads front and rear. Currently, no ducting, but that will change over the next few days.

Thanks in advance for any advice or thoughts.
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Old 09-04-2012, 05:57 PM   #2
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I assume you're using the little return springs front and rear?
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Old 09-04-2012, 06:20 PM   #3
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Yep, using the springs, actually thought about doubling up on them to see if the extra tension would help. I just know at this point I need to do something to free up the wheels. On cold brakes the car rolls with no resistance, once hot its all I can do to push the car, not having much hp or tq, every little bit of rolling resistance hurts.
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Old 09-04-2012, 06:22 PM   #4
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So is it the brakes or the hubs? Have you tried pulling the pads with the brakes hot and spinning the hub then?
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Old 09-04-2012, 06:31 PM   #5
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It's the pads, if I give a little rock to the calipers to create some space between them and the pads the wheel frees right up. I have good grease on the pins, and the pins are straight, new master cylinders as well, so I don't think they are hanging up. Also if you get on the rumbles at all, you have to give the pedal a tap or you have a long pedal at the next brake zone.
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Old 09-04-2012, 07:33 PM   #6
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If rumblestrips cause knockback, you have a bad bearing, bent spindle, or some other core issue that should get resolved.
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Old 09-04-2012, 07:51 PM   #7
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spindles are straight, hubs have no play torque at 137 pounds. Could you elaborate on why the rumbles causing knock back mean that I have a bad hub bearing or spindle? I am confused.
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Old 09-04-2012, 08:16 PM   #8
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How are the caliper seals? Are the piston smooth? I polish the pistons and pins.
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Old 09-04-2012, 10:12 PM   #9
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Quote:
Originally Posted by hingstonwm View Post
spindles are straight, hubs have no play torque at 137 pounds. Could you elaborate on why the rumbles causing knock back mean that I have a bad hub bearing or spindle? I am confused.
The rumbles will make the wheel/hub move on the spindle and the rotor will force the caliper open. This only can happen if there is play.

Besides that are you running anti-drainback valves?
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Old 09-05-2012, 12:14 AM   #10
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Is there clearance at the master pushrods pedal at rest? (freeplay)
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Old 09-05-2012, 11:49 AM   #11
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Yes, there is free play. I will check my hubs again to ensure all is tight.
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