Brakes , What works ....... Really works

['Cuda Hunter]

Thanks autoxcuda!!  This thread has helped more than just chryco!

[Supercuda]

The info from Autox is awesome! Great to get that kind of information into the real world now and then, without some mechanic like me botching the english/jargon translation. Chryco, the issue with your brakes was definitely rotor cooling, as you stated that you still had a firm pedal. If the fluid had boiled, the pedal would've turned to mush. Slots would have helped, as the gases made by your pads were not venting, and causing a "no stopping" complaint. Also, the 10" drums are good for street driving, but marginal at best for any real performance work. Try 11" drums, if you aren't ready for the big dive into 4-wheel disc yet. When you put the 4WD diff breather on, you want to replace the little vent with a real breather filter, and a catch can was de rigeur in the heyday of road-racing these old musclecars. The adjustable prop valve will stay with you, whatever you do, and I don't think you have to have power steering on your car to have the totally cool brake setup. A lot of the engineering will go into the linings, no matter what you do. Whether it's disc or drum, it will take a pretty special compound to deliver the performance required of track conditions. I have the 10.87" discs on my '67 'Cuda, with 11" drums, and I love it. It will give you back most of the dime you stop on, with excellent feel. I do want the bigger rotors, but haven't got the time or money yet for conversion.

[Bullitt-]

OK just to confuse the issue,... humor me please.... , what would it take to modify a classic Mopar knuckle to accommodate the modern hub/bearing?... If this was possible would the brake offerings be less limited than the current configuration?   Am I over-complicating things?

[Moparal]

OK just to confuse the issue,... humor me please.... , what would it take to modify a classic Mopar knuckle to accommodate the modern hub/bearing?... If this was possible would the brake offerings be less limited than the current configuration?   Am I over-complicating things?

I was working at a plant in Michigan a few weeks ago where the produce 1000's of lbs of that ductile iron stuff for the big auto makers. Didnt even have the holes drilled in them. Same with balancers and stuff. The building was full of this stuff being made there. right in the middle of no where. They had a unit there they bought brand new in January and had replace almost everything in it in 8 months. They called me in there to fix it for them. I was going to bring some of their items home to experiment with. Not sure if what wade says would be good or bad. But those hubs usually go with a strut front car.  Figureing out bump steer and stuff could get a little tricky

[Chryco Psycho]

 cannot see any advantage to pressed brg hubs
 I will step up to 4 wheel disc shortly , , I had though of drilling  the rotors but i have no way of slotting the rotors , I will probably just transfer these brakes to my Chall & upgrade the Charger with newer stuff as I donot intend to drive the chall as hard for a long enough period to overheat the brakes that much

[Moparal]

A machine shop by me slotts rotors

[Aussie Challenger]

  Putting slots into standard material rotors may not be a good idea unless the rotor material is thick enough. It could set up a weak spot for fractures. All the slotted rotors I have seen are made of a different composition material, on the street you may get away with it.
  I remeber back in the '60's NASCAR cars were having a problem with heat generated from the brakes transfering to the tyres and bursting them. Wider wheels shroud the air flow over the disc rotors, very little heat disapates through the spoke gaps of a wheel. 

[autoxcuda]

FWIW, the 68 Valiant runs 10" drum with it's 13" disk Brembo caliper custom hub setup.

But the 70 Cuda used to run rear drums early on, but said they would fade.

Probably driving style differences.

You have to dial out rear brake with the 10" drum to keep them front locking. So, I don't think going to the 11" does much of anything on the street. Should resist fading at the track more because of it's bigger mass.

They say the best way to have holes in your rotors is to have them casted in. Same for slotting. Machining those feature promotes cracking. Especially the holes. I don't think slots and holes are "showstoppers" in regards to big improvements.

If you've got major fade and soft pedal, you need more that holes and slots.

Ducting and even running duct fans are much bigger improvements.

[HP2]

Looks like I'm late to the party.

As I recall from you pictures in the "fastest you've driven thread", you car has stock style steel wheels doesn't it? That combined with no ducting is why your brakes faded. A simple hose stuffing air into the rotors will go a long way towards allowing longer braking periods. Yes, multi piston calipers improve feel and bigger rotors improve leverage, but there is still a lot left in those old 11.75s. Heck, even Nascar and Cascar racers are only using 12.12 rotors, which aren't a whole lot bigger. A cheap trick is to slot the pads. Easier than doing rotors and still allows boundery layer gases to escape under hard braking. Other small tricks, stainless steel shims between the pads and caliper help keep heat out of the fluid. Synthetic fluid and bearing grease are also good ideas. I used to use all these things when I was running oval track cars and usually had no problems until races got upwards of 30-40 laps on short tracks but then I had less fade than the comparable 10.5" chevys anyway, so comparably I was still better.

[Chryco Psycho]

I am running slotted pads , 7x15 " steel cop rims with no ducting

[Aussie Challenger]

  When you do install ducts make sure that they are as large as you can get, 4" min. Make the scoop on the outside or start of the scoop even larger, funnel shaped, it helps. You can change the shape of the duct at the exit to blow a more directed charge of air and aim it more to the centre of the disc as the air travels from the centre to the outside of the rotor.     Steel wheels don't disapate much heat except into the tyre and that should be avoided if possible.   

[brads70]

Looks like I'm late to the party.

As I recall from you pictures in the "fastest you've driven thread", you car has stock style steel wheels doesn't it? That combined with no ducting is why your brakes faded. A simple hose stuffing air into the rotors will go a long way towards allowing longer braking periods. Yes, multi piston calipers improve feel and bigger rotors improve leverage, but there is still a lot left in those old 11.75s. Heck, even Nascar and Cascar racers are only using 12.12 rotors, which aren't a whole lot bigger. A cheap trick is to slot the pads. Easier than doing rotors and still allows boundery layer gases to escape under hard braking. Other small tricks, stainless steel shims between the pads and caliper help keep heat out of the fluid. Synthetic fluid and bearing grease are also good ideas. I used to use all these things when I was running oval track cars and usually had no problems until races got upwards of 30-40 laps on short tracks but then I had less fade than the comparable 10.5" chevys anyway, so comparably I was still better.
/quote]







From one oval racer to another! I helped out a guy running a aspen in a street stock class. (His car #14 in on page 2 of Firmfeels pictures ) What I did was used 2 weld on type brackets for a 9" ford ( like $15 each!) cut them and drilled the holes to fit the dodge spindle . Then used full size Chevy calipers ( $18 each) This gave us the choice of many different brake pad compounds . It's a low buck way to put good brakes on a race car! If you can stomach the chevy parts on your mopar! LOL  Worked really well, way better than the biggest stock set up!

[go-fish]

I would say that adding a pump just for the hydroboost would be worth it. I have Wilwood Dynalite 4 piston calipers on all four corners/drilled and slotted rotors with the Hydroboost and it will put you through the windshield.

After driving my Dads SRT6 Crossfire and my 'cuda back to back I think my car stops better.

If you go with the Wilwood rear disc kit w/ in rotor e-brake, beware, the instructions fail to tell you to use a 1/4" spacer or remove the thrust block inside your differential.

[Chryco Psycho]

Well here is where I am at
The Charger has some relative value as it sits being rotisserie restored & well built from there , it will cost me at least 10K more to take this car to the next level & will add nothing to the value , after thinking this over I have put the car up for sale as is I will look for a Viper to go fast in as it is far better to start with . I know Wrong time to sell a car so I my be stuck with it for now & may look at this again later , the car will need better wheels & tires , upgraded suspension [springs & sway bars ] & better brakes & I would replace the heads & cam & add a Petty type front spoiler with ducting to the brakes & carb also + would need the mandatory roll cage & seat belts to race it in the Silverstate or Pony Express runs .
 I also believe the brakes I have may be Far better than waht I experienced ... I recently read an article on bedding in the brakes Before beating on them , it gives the brakes time to get used to each other & transfer some material onto the rotors & achieve full pad contact , the article suggested a few hundred miles & numerous heat cycles to bed them in , this said I drove the car out of the garage stopping twice from 1 mph , drove 75 miles never touching the brakes , stopped at 2 trafffic lights from maybe 10 MPH as I always gear down to slow down , pulled into the track stopping twice at 2 mph & pulled out onto the race track getting over 100 MPH into turn 1 .....probably Not the Best way to bed in the brakes
 I sure appreciate the input though & I do have access to some Huge JFZ calipers but would have to go back to drum spindles & buy rotors to use them

[brads70]

In the circle track world we use brake ( fluid) circulators to keep the fluid from boiling . Use good brake fluid too wilwood makes good stuff.also as I mentioned before try modifying caliper brackets for a 9" rear ( weld on style ) so you can take advantage of the full size Chevy calipers , which lets you have many choices for brake pads that were designed for racing. This works I've done it!  There just are not any good pads for Mopar set ups. The adjustable proportioning valve is good for adjusting the bias as the brakes get warmer as a race goes on.
just my