disc vs drum brakes

grumpyvette

Administrator
Staff member
I frequently have guys ask me about or the subject comes up about the advantages of installing DISC brakes on a performance car like the older muscle cars.
well the fact that a properly set-up and sized set of disc brakes having the potential to out perform drum brakes was completely settled back in the 1950s, when Mercedes, and jaguar , and others proved conclusively at race tracks like Le mans, that the disc brake equipped cars had a noticeable advantage ,that allowed cars to brake later and harder yet still maintain control, theres zero question about the potential ability of disc brakes that are properly matched to the application to out perform drum brakes as disc brakes handle being soaked in water or repeated exposure to high heat levels more efficiently while still stopping the car better.
the radial design if disc brakes with internal air flow passages in the rotor forces cooling air thru the rotor disc, and its design keeps it from trapping water, on its disc or pads surfaces. in some designs disc brake pads and rotors are easily changed in a few minutes ,as they slide onto or bolt onto the bearing hub,making maintenance very easy
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but theres several other factors to consider if your building a performance muscle car clone or rebuilding a true classic muscle car you obviously can,t install parts that were never listed or available for that car and maintain its original characteristics or collector value, but if your interested in increased braking performance many of the more popular cars have disc brake upgrades available and if you don,t mind a few mis-matched parts salvage yards can art times provide reasonable priced components from later year cars that can be easily adapted or swapped into the older cars.
keep in mind swapping too larger diameter tires where they will fit will tend too add addition surface area on the pavement , and this also tends to increase a cars ability to effectively apply the brakes to slow the car, but obviously the cars speed, weight, type of brakes, rotor or drum size and surface area and the time available to dissipate heat build up between applications will effect the cars braking efficiency.
if your not concerned with a matching numbers rebuild a salvage yard and some time spent with a tape measure and on line doing some research will frequently allow you to find a later model car or truck with 4 wheel disc brakes that has similar suspension width measurements, and if your not overly concerned with brand loyalty issues and are willing to do some careful fabrication or use aftermarket kits you will find its not that difficult and at times not that expensive to collect and swap parts , your camaro or mustang might find its got a Lincoln, or GMC, or DODGE, or some pick-up truck rear differential in the cars rear differential installed or some aftermarket components or an adapter kit with components that allow fitting a different production year or models or manufacturers disc brakes but youll have far superior disc brakes.
many times A great deal of the cost will depend on how much work you can do yourself, and what local salvage yards charge for a complete rear differential, Ive seen guys buy complete disc brake equipped rear differential,s from salvage yard out of various luxury cars and late pick-up trucks for $300-$500 so its not always going to cost you as much as some of those more expensive $1500-$2000 aftermarket big brake kits list for to upgrade


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DRUM BRAKES
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DISC BRAKES
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YOULL BE RESTRICTED to drum brakes on many older cars if your trying to stay period correct, and build a numbers matching collector car

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youll be stuck with drum brakes if you're broke... because alot of those conversions cost serious coin! i remember when SSBC was like rock bottom pricing, now they think they are brembo or something! being able to swap hub and brake assemblies from other cars is a definite plus, as you can get the majority of your parts new at autozone, and maybe the junkyard, for a fraction of the cost of alot of those kits.
 
There is a Seller on Ebay that has Disc Brake Conversion kits for under $500.
1 Kit Covers Front or Rear axle.
2 kits required for 4-wheel disc brakes.
SCARCEBIRD is The Ebay Seller.
He covers from 1940-1970's.
I would like to try at least a disc brakes up front in my '63 Pontiac Grand Prix.
Adapter plates bolt to the stock steering knuckles .
Made nice. Stamped and Laser Cut.
What's welded looks strong.
Would like Wilwood but &$$$$.
 
Just want to mention that Drum brakes still have thier place today.
Foot Brake Drag Racing with an Automatic trans like a Turbo 400 without a Transbrake for Super hard launches off the starting line even with a high stall torque converter in the 3,000-4,000 rpm range
Poor man's drag racing.
Rear drum brakes 11-14" inches in diameter have more friction surface area than most disc brake setups.
GM & Ford 9 drum brakes are self energizing.
Front primary brake shoe is shorter than rear secondary.
Braking torque reaction causes the Rear Secondary to dig hard into the drum.
More input torque the harder it holds the drum motionless.
Ford 9" drum brakes & 1957-64 Pontiac Olds 9.3 Factory drum brakes are actually pretty light in weight .
Take an all billet aluminum drag brake disc brake setup to be lighter & have more braking torque.

Something to consider.
Front brakes do 75-80% Braking whoe slowdown work.
Disc added up front if low in $ best idea initial.
 
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more than a few guys converted cars to use the huge aluminum drum brakes available on mid and late 1960s and early 70s BUICKS,
salvage yards at times sell the whole rear differential from those old buicks very reasonably, and while it takes some fabrication skill to convert rear brakes to front brakes its certainly not something thats not been done hundreds of times before!

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YES A THIN COAT OF GREASE , on the back of disc brake pads ,WILL WORK, to reduce vibration and noise
obviously selecting and proper use of the correct lubricant tends to work better
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interesting brake pad replacement video with a few universal tips worth knowing
 
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