11” to 11.75” disc upgrade?

[Mike DC]

    

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

But that's my point - a 50yo Charger does have to share the road with modern cars.  

I'm not trying to gripe about the 11.75" rotors.  I'm just saying 9-10" front drums aren't enough.  Not if the car sees tight traffic over 40-50 mph, which is getting pretty common now. 

[b5blue]

I get ya, it depends on use mostly. Weekender/Daily/Show-Event/Race I drove my 70 for many years on 10 inch drums as my primary car. (Including 600 mile a day road trips.)

[c00nhunterjoe]

   

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

But that's my point - a 50yo Charger does have to share the road with modern cars.  

I'm not trying to gripe about the 11.75" rotors.  I'm just saying 9-10" front drums aren't enough.  Not if the car sees tight traffic over 40-50 mph, which is getting pretty common now. 

And my point was 99% of us with 50 year old cars are not using them as daily drivers and do not frequent the interstate during rush hour with them.... my comparison of tires to braking ability and drums to disc and then to the op of 11 to 11.75 rotors was for relevancy. I never argued drums were better then disc on these cars.
     As a side note. I dont think most of our insurance companies would be too thrilled about daily driving the interstates in rush hour. I know most classic insurance companies have restrictions and would fight you on an interstate wreck at those congested times of day. My state itself has rules for historic tags so god forbid something happens, you better have proof of why you were in that situation with that particular car.
   

[Mike DC]

   
That's true about the insurance company issues. 

But still.  I live in the outskirts of a medium size midwestern city.  It's not one of the big coastal urban centers.  In my area dense highway-speed traffic is normal for 2-3 hours out of the 24, five days out of the seven.  It's a very normal thing. 

[Brass]

I live within 2 miles of downtown Seattle, and congestion is almost always bad, day or night. My car has to keep up with the demands of modern traffic whenever I drive, and freeways are practically unavoidable entering or leaving town. So far, 11.75 discs, EBC pads, and a hydroboost unit seem capable enough.

With respect to insurance, I think insurance companies factor in your ZIP code when calculating rates. Also, I don't drive my car more than what I have indicated to them.

[c00nhunterjoe]

On that logic then , i drive mine in traffic, on c12 race gas, with skinny front tires and slicks, and never had a problem with stock brake setups.

[flyinlow]

I have upgraded from 11 to 11.75" brakes.  Hawk HPS pads and slotted rotors. 11 inch Right stuff kit on rear. I did this while I had 15 " BFG's. Some improvement with the 11.75, not a big change. When I went to 18 wheels and G Max  05's tires the larger brakes really started see an improvement .

[b5blue]

Being the caliper/pads are the same for both I think the largest gain is H.D. or repeated use. Even greater so with upgraded pads and rotors like flyinlow has. (I'd like a link to what you got?)

[flyinlow]

https://www.summitracing.com/parts/hwk-hb643f-595

front pads

[b5blue]

Thanks! I'm not boosted, stops well looking to upgrade, how much and where on the rotors if you don't mind? (My rotors used 1980 St. Regis as lookup.)

[Dano 1]

1978 Chrysler Cordoba is a reliable cross-reference for the 11.75" rotors. My go-to these days is rockauto.com and they have rotors starting at $37.79 + shipping.

https://www.rockauto.com/en/catalog/chrysler,1978,cordoba,6.6l+400cid+v8,1062717,brake+&+wheel+hub,rotor,1896

[b5blue]

I've got rotors bought long before slot/hole type were ever something you could buy. Looks like 140 is average now, surprised even Rock has them now! Thanks 

[Nacho-RT74]

I got my 10.90" drilled and slotted rotors for my Charger 8 years ago!!!!... Maybe around $40 each as far I recall from Rockauto. Centric brand. Can't recall the exact price but it was barelly around 25-30% more than the stock replacements. Really good priced. Of course I didn't go with 11.75" because I still don't have the caliper brackets... but some day!

Accomplished with Bendix ceramic pads and Raybestos metallic rear shoes

[flyinlow]

Thanks! I'm not boosted, stops well looking to upgrade, how much and where on the rotors if you don't mind? (My rotors used 1980 St. Regis as lookup.)

Zinc plated rotors with slots.(plain and drilled/slotted were options.) Forgot the vendor,  I think about $150 a pair 5-6 years ago.  


I did sand the zinc off the wear bands before I did the brake in ritual.

[b5blue]

Thanks for the info guys! 

[375instroke]

Here's my  Friction material is nothing to cheap out on, and run the biggest stock size drums or rotors you can, for everyday driving.  Here's why I think that.  I have a 273 Dart with 9" drums, and it stops great, at least once.  Probably has real asbestos shoes.  My 340 Dart with the "HD" 10 " drums stops like crap.  Both cars are untouched by me.  Have a '64 Dodge 880 that had the worst brakes of any car I've owned.  From 60 to 30 was ok, but then it acted like someone sprayed oil on the shoes, and started shaking violently.  Had the shoes relined at a local brake place that does mostly big trucks.  That car stops great now, with just the fronts redone.  My Charger R/T with the big drums could stop fine at freeway speeds one time, but after that, it had to cool off if you wanted to stop again.  From 80mph, it was a struggle at the end.  It has the 11.75" discs now, With Raybestos semi metallic pads, and it stops great.  Another Dart I had, with the 11" discs always stopped great till I drove around San Francisco.  With all the hills, they got hot, and stopping ability was greatly diminished.  Now for the race car. which is a Fox Mustang.  We're talking up to 36 hour road course endurance racing.  The brakes were off an SVO turbo Mustang, 11" discs front and rear.  Stock couldn't keep up.  Drilled and slotted rotors couldn't keep up.  Hawk Blue pads were really good, but those, with drilled and slotted rotors, and cooling ducts, it still needed improvement.  Those pads lasted 28 hours, and when they woke me up for my turn to drive, they told me "We had to put those parts store pads on.  Don't enter the first turn any faster than the speed you want to die at."  Going up to 13" Cobra rotors and calipers, which are $40 each, at any Schmuck Auto Parts, and Hawk Blue pads, could drop that car from 156mph into a hairpin, lap after lap, in 95deg ambient temps.  My take is run the largest rotor you can, and don't skimp on the pads.  I really think drums get such a bad rap because people put the cheapest piece of crap shoes they can find on there, and if you look up the coefficient of friction on them, it's less than steel on steel.