Disc Brake Upgrade

[Long Island RT]

New guy here - Although I've been lurking for a few months as I've finally had some time (and money) to re-assemble my '69 RT.  I took it apart in 1990, got married, house... kids...etc.

Here's my question(s):

I am upgrading my entire brake system from drum to disc.  I've read (somewhere) that if I use 12 inch rotors I can switch over to manual brakes (is this true? – I hope so because my motor will not have the vacuum needed for power brakes).  I already have the summit rear disc brake kit for my 8¾ but I was thinking of getting the Wilwood kit 140-9828 (12.19" rotors) for the front.  I called Wilwood – and they can't guarantee that it will fit my car although they will guarantee it will fit on a 69 Satellite, GTX or Roadrunner because that's where they tried it (even though Summit lists them under a 69 Charger as well as 70 Cudas and Challengers).  They do have a 10.75" kit they do guarantee.

I've read conflicting things about steering knuckle height and switching to the tubular uca's clears up all the issues, but before I buy this stuff I'd like to know.  I've also read the "cheaper" ways to upgrade by using late model spindles, rotors and calipers, but by the time I find all that stuff and rebuild the calipers it'll be another 18 years.....

Is there a difference in drum spindles from the Plymouth or 70 E-bodies?

Will the extra rotor diameter make a big difference in stopping? (17" or 18" after market wheels are in the works)

Has anyone had good results with these Wilwood kits or is there something else you would recommend?  I saw some people favoring the SSBC force 10 set-up and (which is a little more pricey) and someone else had warpage problems with Wilwood rotors.  SSBC lists theirs 11.25" rotors as 0.8125" thick – I can't find any thickness info on the Wilwood 12.19" street rotors.

Thanks in advance!

[71charger_fan]

If it fits a '69 Satellite, it'll fit a '69 Charger. Same front suspension pieces. If you're buying a kit to fit stock drum spindles, the question about the later, taller spindles is moot. You don't need larger rotors to run power brakes. Power brakes don't develop any more line pressure than manual brakes, they just take less pedal effort. I have manual 11" disks on the tall knuckles in my '71.

Larger diameter rotors are the equivalent of a larger lever. You should get better stopping performance.

I'm currently waiting for Dr. Diff to get calipers back in stock so he can send me a rear disk kit.

[Long Island RT]

Thanks for the info!

Who's Dr Diff?

[71Charger JT]

i have the 12.19 with 4-piston on my '71 Bee... no fitment problems.... contact Dean at hotrodsusa.com....1-888-875-6666,  he knows his industry.

[71charger_fan]

http://members.aol.com/doctordiff/

[knitz01]

With the 12.19 w/ 4piston cal. can you fit 15" wheels?

[Rolling_Thunder]

dont think so

[Long Island RT]

Nope - You need at least 17" to run the 12.19's.  An even then he (Dean @ Hotrod) said the rim should be carefully checked.  Something about your rims should be at least 5" more than your brake rotor.

[Mike DC]

The entire musclecar hobby is overdue to focus some attention on hi-po brakes that fit inside smaller wheels.


Any setups with rotors that are over about 10.5-11 inches in diameter will usually not clear 15" wheels. 

 

[BlueSS454]

I used a complete setup off a '78 Magnum on my Charger.  All I did was use the Charger lower ball joints and rear mount the calipers.  I did have to use offset UCA bushings in order to get the car into alignment.  No clearance isses at all.  No bump steer issues either.

[Steve P.]

WAIT ONE MINUTE....  If you want to use the 11.75" MOPAR discs, (more commonly known as the 12" disc),  as they used in most police cars for many 70's years cars, YES, you can use a 15 inch rim.

There is a thread on here that goes into much detail on this.. 

Also, I have used and know many people using the later model LONGER/TALLER spindles that have ZERO complaint about bump steer or alignment problems.

Yes, the industry has come up with even better braking systems, but the fact is 95% of us have no need for anything more than the 10.75 discs found on a ASPEN....

[71charger_fan]

My Dr. Diff kit has arrived. By the end of the week, the '71 should have 4-wheel disk brakes. Not bad for a car that started out with 4-wheel drums. I noticed that his website is no longer up, hopefully he either has, or will create, a new one.

[bull]

WAIT ONE MINUTE....  If you want to use the 11.75" MOPAR discs, (more commonly known as the 12" disc),  as they used in most police cars for many 70's years cars, YES, you can use a 15 inch rim.

There is a thread on here that goes into much detail on this.. 

Also, I have used and know many people using the later model LONGER/TALLER spindles that have ZERO complaint about bump steer or alignment problems.

Yes, the industry has come up with even better braking systems, but the fact is 95% of us have no need for anything more than the 10.75 discs found on a ASPEN....

I agree with Steve except I think the Aspen rotors are 10.87" instead of 10.75" if it matters. While there is much debate about the 10.87" rotor setup and the assumed dire effects of the spindle height, it seems that the danger is all academic because no one has ever been able to point to any real problems despite years of use by many classic car owners. Either disc brake set is going to be much better than any drum brake setup. More than enough to deal with our needs, and right now it's nearly impossible to get your hands on the 11.75" parts. That said, all you really need to find at a junk yard to run the bigger brakes is the spindles and the caliper brackets. Everything else can be purchased new or rebuilt at just about any aftermarket parts store.

Here's the story on the 11.75" setup. It warns against using the Aspen brakes but as mentioned there's been no reports of any problems with them and the installation process is virtually the same for both.

To answer your question, many people run manual disc brakes with no problems. That's what I'm going to be doing.