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View Full Version : Drums Vs. Disc



Zaq
03-20-2013, 10:45 AM
So I started a thread a while back about "Power Vs. Manual" brakes and everyone basically said "If your car has power brakes in it, put them back in it, no sense switching to manual". I am still shopping around for what I want to do with the brakes (plenty of time since I am still working to get it running) but wanted to start a conversation about the advantages of switching to Disc brakes over drum. Obviously performance is better with disc but is it performance I will need? I don't plan to beef up the motor much, just want a good runner to cruise around town. Am I going to notice the performance increase? Is it worth the money spent? Discs all around or Discs front and drums back? I don't necessarily need all those questions answered, I just wanted to throw some questions out there to get the opinions flowing. Thanks!

67440Dodge
03-20-2013, 11:51 AM
In a perfect world, drum brakes will outperform discs hands down. The amount of surface area that the friction material contacts with drum brakes is about 300% greater than a disc brake setup.

However, all braking systems have a serious enemy. Heat dissipation. The harder the brakes are applied, the more heat that's generated. The more heat that's generated, the less efficient the brakes become. It's called brake fade. Due to their design, drum brakes cannot dissipate the heat generated quickly enough. To combat this, the disc brake was invented. The open design of the braking surface and cooling slots in between the sides of the rotors (on most of them) help dissipate the heat. The downside to discs is they require more pressure applied to the braking surfaces to slow the car down. (Hence why most cars that came with disc brakes have a power booster).

Will you notice a difference converting to disc brakes? Putzing around town barely getting above 25mph? Probably not. But, that first time you have to do a hard braking when at higher speeds, you'll thank yourself for converting.

4 wheel discs in a cruiser? Not necessary I think. Yea they look nice, but unless you're doing lot of hard driving/braking it's overkill.

badmopar67
03-20-2013, 12:39 PM
front disc's. ftw

ws27
03-20-2013, 02:14 PM
I run both 4 whl drum and factory disc front/ drum rear. Mike is right, disc will stop you much better if you have to do a few hard high speed stops in row. That can happen in real life driving on highway in city limits. Some people don't mind four wh durm, and some wouldn't be caught dead with them. Your call.

For me, I like to keep my cars somewhat origional. The blue GTX is a 440 auto with four wheel drum and I can honestly say I've never had a brake fade problem yet. But I do drive like a little old lady and am a truck driver so braking distance is always on my mind. The other GTX is 440 4 spd with front disc, and yes I'm sure it will stop faster, but again, Ive yet to find out.

Ask yourself how you plan to drive and what you want from it.

Four wheel really is a waste of money to get all it's performance, you really need ABS.

Good luck

Zaq
03-20-2013, 02:47 PM
I am a pretty conservative driver these days... had you asked 20 year old me (8 years ago) I would have definitely needed the discs but I was driving a twin turbo Stealth at the time so my car enabled that sort of rediculous driving. I'm over that and tend to leave quite a bit of room and have no problem putzing along with the flow of traffic. I think I'll put it back together with drum all around but replace my master cylinder with a dual pot. That should enable me to switch to discs up front at a later time if I so choose. Thanks for the input!

theman440
03-20-2013, 07:14 PM
Another down side of drums is that often hard spots develop in the drums and they tear up the linings, wearing them out quicker, making grinding noises and if it gets worse on one side the brakes will "pull" Once you get the hard spots they never go away, you can have them ground out but I doubt you could find someone with the equipment, and they will come back eventually as the softer metal wears out. I've experienced all of this personally. I've got factory 10.5 inch late A-body brakes (with manual master cylinder) on my 3600 lbs race car that goes 126 mph in the quarter and it stops AWESOME, I don't even have metallic pads on it. In a panic stop situation, discs are much easier to modulate therefore easier to contol tire lock up and help avoid disaster. I always say if you are going to drive it often, put disc brakes on it - it's easier than you thinkl. I'll get off my soap box now...

Racer Brown
03-21-2013, 12:42 PM
I run both 4 whl drum and factory disc front/ drum rear. Mike is right, disc will stop you much better if you have to do a few hard high speed stops in row. That can happen in real life driving on highway in city limits. Some people don't mind four wh durm, and some wouldn't be caught dead with them. Your call.

For me, I like to keep my cars somewhat origional. The blue GTX is a 440 auto with four wheel drum and I can honestly say I've never had a brake fade problem yet. But I do drive like a little old lady and am a truck driver so braking distance is always on my mind. The other GTX is 440 4 spd with front disc, and yes I'm sure it will stop faster, but again, Ive yet to find out.

Ask yourself how you plan to drive and what you want from it.

Four wheel really is a waste of money to get all it's performance, you really need ABS.

Good luck I'm in full agreement, Rich!

SmartPatrol
04-01-2013, 09:00 PM
My 66 came with no booster, and 4 wheel drums. I did a Wilwood front disc conversion added a booster, and I am in vacuum loss hell right now. The brake pedal doesn't feel safe. Beware if you have any sort of cam other than stock, you may end up in the same situation as I am. Not stoked.

ws27
04-01-2013, 09:50 PM
Do you know what vacuum you are running? If it is indeed too low, you might want a vacuum pump. Otherwise invest in a double diaphram booster.