Better braking power?

[drk]

I've got a 66 Mustang. 289, T5 and cobra disc brakes so far. Everything else is mostly stock. I was expecting the braking power on these disc brakes up front to be better. They are fine, but not great. What are some ways that I can improve braking? The brakes were installed at a reputable Mustang shop as well.

I was thinking rear brakes and lighten up the car.

Also, thinking about going with an Rack and Pinion setup. Any personal experiences are welcomed. Also, thinking about going with some AFR 165 with 1.6 rollers. This would be on a freshly rebuilt 289 (stock specs). Also, which headers clean Rack and Pinion and T5?

Thanks.

 

[CraigMBA]

I'm thinking you have something wrong with your brake setup, either in the master, or the rears.

Baer Aftermarket Brakes - Hot Rod Magazine

I have this same setup on my car (except I used the Mustang Steve kit). It uses the same calipers and sized rotors and master cylinder that baer uses. I haven't drove it yet so I can't say how hard it stops.

 

[tx65coupe]

You could add power brake booster to the car if it doesn't already have one.

We have a 97 Cobra and the brakes on it work really good, but require some pedal effort even with power brakes.

 

[Rusty67]

What disk brake setup do you have on there now ? Do you know which master cylinder you have, what the bore size is ?

Do you have power brakes now ?

 

[phutch11]

When I went to front disks, the results were night and day.

The pedal travel was longer, but it stopped sooner and straighter.

I'd rebleed the brakes to make sure you've got any air out.

Also get some real pads...check out Hawks.

Good luck...

Posted via Mobile Device

 

[hipo_p51]

get rid of any rubber brake lines. cobra auto has a set of steel braided lines that should fit your car. i have stock sized discs with racing compound pads up front and 11" drums in the back. my car stops well when compared to the old parts and rubber brake lines. hope this helps.

 

[2+2GT]

Define "better". Easier pedal? No fade while driving down the hill into Scranton Pennsylvania?

 

[hipo_p51]

Define "better". Easier pedal? No fade while driving down the hill into Scranton Pennsylvania?

easier pedal, no fade and better braking performance.

 

[Rusty67]

Fade is caused by heat, both when the components get hot and when the brake fuild gets too hot. If they are fading that bad then vent them. What size bore is your MC ? If you don't want to go to power brakes you may need to step down to the next smaller bore for easier pedal effort.

Stainless steel lines are good to keep compliance in the system down which results in more application of force from the pedal to the braking system.

 

[2+2GT]

easier pedal, no fade and better braking performance.

Did you add power boost as well?

 

[hipo_p51]

no power boost. the 2 reservoir master cylinder along with the braided lines, good pads up front and big drums in the back are a great package for 65/6 car. the new master cylinder made a the pedal effort a little less. everyone seems to believe the 4 wheel disc is a must. new bigger drums work equally as well. i am sure how ever if i had 17 plus size wheels with large discs up front that would be a better setup. however i like the more vintage look with the drums and 16 inch wheels. the larger 17 plus wheels my be popular, but do not look right on the smaller 65/6 car. just my opinion.
i know this is a little off topic, but just wanted to get the info out to others who are reading.

 

[2+2GT]

no power boost.

OK, that explains it. Disc brakes require higher hydraulic pressure than drum brakes, and without a booster, your foot has to create this pressure.

Some 66 GT350H had an interesting solution, a master cylinder with dual internal pistons, which telescope, providing higher pressure by reducing the diameter of the cylinder.

View attachment 255968

 

[phutch11]

To generate braking power what you are trying to do is to generate the maximum amount of torque to resist the motion of the car.

To increase the amount of torque that the braking system can generate, you can increase the moment arm of the system (i.e. the rotor diameter) or you can increase the frictional force applied by the caliper/pad to the rotor.

Increasing the rotor diameter has some obvious limits in terms of packaging within the wheel, but other limits are hit due to increasing unsprung weight and increasing the rotational inertia of the car - i.e. making it harder to accelerate.

So, you are left with increasing the friction force applied to the rotor. Force due to friction is defined as the product of the normal (clamping) force times the coefficient of friction of the materials that are sliding against each other.

You can increase the clamping force by making sure you have good fluid in the system (no air or water), getting 6 piston Brembo calipers, upgrading to stainless steel brake lines, getting better MC's, etc. But there are limits to the amount of force that you can apply - mostly cost related, but also capliers will start to spread when huge loads are applied.

OR, you can increase the coefficient of friction of the brake pads. Thankfully, this is easy - just buy some good brake pads.

In all seriousness, for $70 bucks you can get a set of Hawk pads that will drastically change how your car brakes. Get on CornerCarvers.Com and ask some of the serious Autocrossers or Opentrackers what they'd recommend for you for the street - it will be a good bleed with quality fluid, a set of good pads, and a good bedding in.

It ain't as sexy as rear discs, but it works.

Good luck...

 

[66Runt]

The car in the signature below has a "Cobra brake" setup.
Average stopping distance from 60mph to 0 is 122' with the 6 cylinder engine. Best was 117'. Handling at threshold was excellent. Road was a bit rough with slight dust. Needs a bit more bias to the rear. I was only able to get three back to back runs with the telemetry hooked up. I ran a little more than 1,500 very hard miles before pulling the car back down for the V8 swap. Brakes performed flawlessly thoughout that time.
The Cobra brake system requires a power booster, and a 1" bore master cylinder that has a 60-40 bias.
Good luck, it's an awesome system once you get the correct pieces.
There is a small write-up on the web site in the signature. Hth,