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.

 

I assume you're using the little return springs front and rear?

 

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.

 

So is it the brakes or the hubs? Have you tried pulling the pads with the brakes hot and spinning the hub then?

 

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.

 

If rumblestrips cause knockback, you have a bad bearing, bent spindle, or some other core issue that should get resolved.

 

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.

 

How are the caliper seals? Are the piston smooth? I polish the pistons and pins.

 

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?

 

Is there clearance at the master pushrods pedal at rest? (freeplay)

 

Yes, there is free play. I will check my hubs again to ensure all is tight.