Drums to Disc '67
08-04-2009, 12:08 AM
#11
6th Gear Member
Join Date: Aug 2007
Location: Elk Grove, CA
Posts: 5,896
Unless you do something like Mustang Steve's Cobra brake swap, stopping power is going to be about equal between discs and drums. Even then, the big limiting factor is tire traction, not braking friction surface area.
However, it's much easier to modulate discs than drums. Drums like to lock and stay locked, while discs take more force to lock up and don't self-energize like drums, so they let go faster. Discs also stop straight reliably. Drums may stop straight immediately after adjusting them, but you can't adjust them every time you drive. Stabbing my drum brakes in an emergency required a quick prayer beforehand and a readiness to jerk the car back straight if/when it swerved out of the lane.
While discs do take more pressure to operate than drums, that does not always result in more pedal effort. Pedal effort depends on m/c bore surface area vs caliper piston surface area. My manual OE KH 4-piston brakes are actually slightly easier on my leg than the old manual drums. I don't have to stand on the brakes anymore to get the car to stop, or to hold it on a hill.
As far as replacement front lines, I'd recommend fabbing new lines. They'll be much cheaper, and while it's a slight PITA, it's worth the effort. My custom bent lines fit better than the ones I pulled off. Just make sure you have some good tubing benders.
However, it's much easier to modulate discs than drums. Drums like to lock and stay locked, while discs take more force to lock up and don't self-energize like drums, so they let go faster. Discs also stop straight reliably. Drums may stop straight immediately after adjusting them, but you can't adjust them every time you drive. Stabbing my drum brakes in an emergency required a quick prayer beforehand and a readiness to jerk the car back straight if/when it swerved out of the lane.
While discs do take more pressure to operate than drums, that does not always result in more pedal effort. Pedal effort depends on m/c bore surface area vs caliper piston surface area. My manual OE KH 4-piston brakes are actually slightly easier on my leg than the old manual drums. I don't have to stand on the brakes anymore to get the car to stop, or to hold it on a hill.
As far as replacement front lines, I'd recommend fabbing new lines. They'll be much cheaper, and while it's a slight PITA, it's worth the effort. My custom bent lines fit better than the ones I pulled off. Just make sure you have some good tubing benders.
08-05-2009, 12:07 PM
#13
6th Gear Member
Join Date: Aug 2007
Location: Elk Grove, CA
Posts: 5,896
If you want to shorten your stopping distance? Use Mustang Steve's Cobra disc brake conversion and upgrade to 17" wheels and sticky tires. Brake boosters don't decrease stopping distance, just reduce pedal effort. And like I said, you're not going to really improve stopping power with a standard disc conversion.
That said, I think you'd be happy with an OE KH-style disc brake conversion. They're good brakes that will stop the car straight with much more control than the factory drums. I drive my manual disc car hard on occasion and I have no complaints.
That said, I think you'd be happy with an OE KH-style disc brake conversion. They're good brakes that will stop the car straight with much more control than the factory drums. I drive my manual disc car hard on occasion and I have no complaints.
Thread
Thread Starter
Forum
Replies
Last Post
Boostaddict
Lethal Performance
2
09-08-2015 09:56 PM
