News:

It appears that the upgrade forces a login and many, many of you have forgotten your passwords and didn't set up any reminders. Contact me directly through helpmelogin@dodgecharger.com and I'll help sort it out.

Main Menu

11” to 11.75” disc upgrade?

Started by rikubot, January 20, 2020, 02:10:07 PM

Previous topic - Next topic

rikubot

Got an easy one for ya. I bought a disc upgrade from classic a while back for the 11" disc, spindles, calipers, etc. I am considering doing the upgrade to 11.75". Will the rotors fit right on the the spindles and if so are the only parts I need the caliper bracket and rotors? Thanks guys/gals.

- Mike
'69 Charger, 440/727

Nacho-RT74

dunno which one you got, but if upgrading on stock parts setup ( laters Mopars ), yes, so simple like that
Venezuelan RT 74 400 4bbl, 727, 8.75 3.23 open. Now stroked with 440 crank and 3.55 SG. Here is the History and how is actually: http://www.dodgecharger.com/forum/index.php/topic,7603.0/all.html
http://www.dodgecharger.com/forum/index.php/topic,25060.0.html

rikubot

'69 Charger, 440/727

b5blue

Uses every bit inside of a 15" wheel. My Torque Trust 15X8's are so close they popped the balance weights off.

Kern Dog

I didn't click on the link but....
The OEM 11 and 11.75 brakes used the same caliper and knuckle. (People incorrectly call them spindles) The larger rotors use a longer caliper bracket.

rikubot

I hadn't considered that. I run Magnum 500s, 15x7. I bet those wheel weights would be history. I appreciate your input Kern. One more reason to pass on the "upgrade"
'69 Charger, 440/727

Dano 1

Somewhat related to the OP's original question, does anyone have opinions on how much better the 11.75" rotors actually are? I'll be converting my '69 from front drum to disc using all the oem parts and have both sets of caliper brackets. My original plan was to go straight for 11.75" rotors but now I'm hesitating due to wheel options down the road. Does anyone have first hand experience going from 11" to 11.75" rotors that can speak to any real improvement in performance?
1969 Charger 383 2bbl, R4 red, White hat special project

Check out my website for 3D printed restoration parts and accessories.
www.nextgendesignsnc.com

b5blue

  My car is a daily driver and for that I went heavy duty. Think in terms of brakes are heat pumps so bigger mass = better. Calipers/pads the same yet placed outward more = better. If your not out in street traffic all the time, doing extended road trips or some kind of sport I don't think that edge is worth the weight.
25 years ago when I started looking for parts 11 3/4 setup was the cat's meow but now with drilled/slotted and better pads smaller could match but be more efficient.

Nacho-RT74

there are 11.75" drilled and slotted rotors at Rockauto.

I'm just waiting to find caliper brackets for pins calipers ON A DECENT PRICE ( or maybe if somebody find the accidentally at some JY up there and is so NICE to sell/send to me LOL ) to proceed with the upgrade
Venezuelan RT 74 400 4bbl, 727, 8.75 3.23 open. Now stroked with 440 crank and 3.55 SG. Here is the History and how is actually: http://www.dodgecharger.com/forum/index.php/topic,7603.0/all.html
http://www.dodgecharger.com/forum/index.php/topic,25060.0.html

Kern Dog

A larger diameter rotor gives better "leverage" for better braking. Even if the same caliper and brake pads are used, the larger rotor will stop the car faster in shorter distances.

b5blue

Yea but the question was "How much better"?  :scratchchin: 12% better?

mrob

b5,
I did this swap on my 69 Coronet. Originally had 74 A-body 10.87 inch rotors and the A-body calipers with semi-metallic pads. Then went with the Dr. Diff 11.75 inch brake kit and kept the A-body calipers with semi-metallic pads.
In my opinion, it's not a "night and day" difference. The biggest difference I feel is when slowing down from highway speeds. I notice that now, the pedal effort is a little lower and I come to a stop in a shorter distance. Around town, I really don't feel much of a difference.
The bigger brakes would probably be better in emergency stop situations, but I haven't had any yet.
Hope this helps

bc3j

I did the 11.75" change on my E Body. Found a slight improvement and like it. My better change was using organic pads. The rotors are thick and don't heat up for me in ordinary driving for the semi metallic pads to work well for me. The organic pads, for me, are better. I don't race the car just cruising, but it will stop very well from highway speeds if needed (and it was on one occasion where a lane change in front of me caused a rather rapid stop). Edit: My mistake, my pads are FF friction coefficient and work well.

As far as wheel weights, I had them stuck as near as possible to the hub and told the installer to use low profile weights. They clear ok and don't interfere with the caliper, the higher profile weights will hit the calipers. My 15" wheels are steel and use the traditional rim mounted weights on the inside of the rim only, requiring stick-ons to be added near the hub. The outside of the wheel is clear of visible weights. I also use the slider type calipers.

For your consideration, I got rid of the Chinese steel races in my 11.75" rotors immediately.  I replaced them with Timken bearings and races.  

Nacho-RT74

Quote from: mrob on January 29, 2020, 10:20:47 AM
b5,
I did this swap on my 69 Coronet. Originally had 74 A-body 10.87 inch rotors and the A-body calipers with semi-metallic pads.

They are actually not A body specific, but any Body regular equipment.
Venezuelan RT 74 400 4bbl, 727, 8.75 3.23 open. Now stroked with 440 crank and 3.55 SG. Here is the History and how is actually: http://www.dodgecharger.com/forum/index.php/topic,7603.0/all.html
http://www.dodgecharger.com/forum/index.php/topic,25060.0.html

Dano 1

Thanks for the feedback guys, I understand the theory/science of larger rotors but was really looking for seat-of-the-pants feedback so this was great. Since I have both brackets and the calipers/pads are the same I may just give the 11" rotors a shot first and then I can always upgrade later for the price of rotors (cheap).
1969 Charger 383 2bbl, R4 red, White hat special project

Check out my website for 3D printed restoration parts and accessories.
www.nextgendesignsnc.com

Highbanked Hauler

I have 11:75 on mine with 15 in. wheels and haven't had a problem.  I never had any complaint against 11 in. drums  and went to discs because of drop spindles only.  I can't see why you would be throwing wheel weights because of caliper position.
69 Charger 500, original owner  
68 Charger former parts car in process of rebuilding
92 Cummins Turbo Diesel
04 PT Cruiser

Bronzedodge

I'm about to do this exact change in a few weeks.  I'm figuring the steel rim is thinner than an alumunum, or Mag wheel.  The factory didn't have weight problems.  I'll post in a month or so.
Mopar forever!

b5blue

Quote from: Highbanked Hauler on February 24, 2020, 05:08:05 PM
I have 11:75 on mine with 15 in. wheels and haven't had a problem.  I never had any complaint against 11 in. drums  and went to discs because of drop spindles only.  I can't see why you would be throwing wheel weights because of caliper position.
15X8 Torque Thrust rims with weights clipped on inside edge. They seared off with a little pop. What's the deal with the drop spindles, how low are they?  :scratchchin:
Got any pics?

b5blue

Quote from: Bronzedodge on February 24, 2020, 07:42:00 PM
I'm about to do this exact change in a few weeks.  I'm figuring the steel rim is thinner than an alumunum, or Mag wheel.  The factory didn't have weight problems.  I'll post in a month or so.
Running factory 15" junkyard rims (80's New Yorker I think.) was no problem with anything including weights.  :2thumbs:

c00nhunterjoe

If you have big wheels and big tires that will hold through extra braking, you will notice more then with little wheels and little tires. What good are viper brakes if you have a 205 tire on the front? The stock 4 wheel drums will lock up the brakes on command without hesitation,  but slap on some corner hugging suspension and tires and they will fade under repeated heavy abuse. Same concept with 1 disc setup over another. Ive found with the majority of "disc upgrades" its more a matter of want then need. And that is perfectly fine.

Highbanked Hauler

Quote from: b5blue on February 25, 2020, 09:30:41 AM
Quote from: Highbanked Hauler on February 24, 2020, 05:08:05 PM
I have 11:75 on mine with 15 in. wheels and haven't had a problem.  I never had any complaint against 11 in. drums  and went to discs because of drop spindles only.  I can't see why you would be throwing wheel weights because of caliper position.
15X8 Torque Thrust rims with weights clipped on inside edge. They seared off with a little pop. What's the deal with the drop spindles, how low are they?  :scratchchin:
Got any pics?
No pictures yet.  My experience only..  They set the front end down 2 in. and  improve the handling some. You will need the adjustable upper control arms to get enough camber adjustment  to keep the tires flat on the road. Alignment specs are not a problem. I run such a tall tire you wouldn't see much of a difference compared to other Chargers. If you are considering doing this pm me and I can tell you the details if you are interested.
69 Charger 500, original owner  
68 Charger former parts car in process of rebuilding
92 Cummins Turbo Diesel
04 PT Cruiser

b5blue

Interesting for sure!  :2thumbs: I'll PM not wanting to hijack topic. 

Mike DC

Quotebut slap on some corner hugging suspension and tires and they will fade under repeated heavy abuse.

It was called "repeated heavy abuse" 50 years ago.  Today it's called "normal driving."  

Many highways in urban areas are basically 75 mph traffic jams.  Everyone is going very fast but you can barely maintain 10 yards of space from the next car.  

And many other drivers carelessly slam on their brakes as a habit.  Why not?  Their car is liable to have 18" wheels, low-profile tires, hydroboosted multi-piston calipers, 13" rotors, maybe an automatic stop sensor system . . .  

c00nhunterjoe

Quote from: Mike DC (formerly miked) on February 26, 2020, 12:43:04 PM
Quotebut slap on some corner hugging suspension and tires and they will fade under repeated heavy abuse.

It was called "repeated heavy abuse" 50 years ago.  Today it's called "normal driving."  

Many highways in urban areas are basically 75 mph traffic jams.  Everyone is going very fast but you can barely maintain 10 yards of space from the next car.  

And many other drivers carelessly slam on their brakes as a habit.  Why not?  Their car is liable to have 18" wheels, low-profile tires, hydroboosted multi-piston calipers, 13" rotors, maybe an automatic stop sensor system . . .  


If we are comparing going from an 11" rotor to an 11.75, to a modern car with all of those gadgets, then we are barking up the wrong tree. A 50 year old charger cannot be compared to a modern car on the highway during rush hour

b5blue

My experience is we create a rolling distraction, I bought all my brake stuff well before anything else was available.