To boost or not to boost...that is the question.

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Beatnik

Beatnik

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So I did a search and still didnt come up w/ the answer I'm looking for so here goes...I want to convert to front discs and am wondering wether I need to use a brake booster or not? I currently have manual drums, but have replaced my old mast. cyl. with a new updated alluminum "disc ready" master. I would like to get a kit that just has the essentials that doesnt come w/ a master or booster. I'm being told that I'm better off buying a kit that comes w/ a booster or at least adding one when I do the conversion, that the clamping power w/out the booster w/ discs just wont be sufficient. I know some are running manual discs out there...gimme your opinions please! Brake booster or not?

Thanks! :thumbup:
 
I converted from manual 9" drums to manual 73+ 11" A-body disks. It takes a lot more foot pressure to reach maximum stopping power than it did with the drums. But as you would expect the disks don't fad and ultimately have a lot more stopping power.

Around town at low speeds the initial bite of the drums is better than the manual disks because of the self energizing feature of the drums but I do not find the not having the booster to be an issue.
 
No need for power brakes IMO. Get a Master cylinder from amid 80's 3/4ton Dodge ram truck. You'll need the 4-bolt to 2bolt aluminum master cylinder adaptor (Manicini has it). This will give you an aluminum updated amster cylinder design and a bigger piston to move more fluid and more braking. I did that swap on my Duster and i love it.....one of the best mods I have ever done.
 
Thanks....that makes sense. I actually installed my aluminum mast. cyl. and new rear wheel cyl's that are larger than stock and I have to apply quite a bit more pressure now than w/ the old parts. I think that's normal though given my situation. I figure, it's new parts replacing old parts that could fail, and I'm going to go w/ discs soon anyway so I'll live with extra pressure needed until the discs go on.
 
A booster does not give the brakes more power in itself it just makes the pedal effort less. Now a booster could give a person more braking power because they may not have the strength to push the manual brake hard enough to achieve the same amount of line pressure as the boost assist vehicle so in this case the manual brake vehicle wouldn't have as much stopping power. But as Dusterb318 mentioned it is the bore size of the master cylinder that changes the braking power and effort. Piston sizing of the caliper or wheel cylinder will also change braking power.

Chuck
 
I went from 10" manual Drum to manual disk with the kit from SSBC :thumbup: (M/C included), and i find it much beter. I didn't notice much diffrence in pedal effort but it stops quicker and straighter (could never get the drums adjusted to stop without pulling one way or the other).
 
Dusterb318 said:
....This will give you an aluminum updated amster cylinder design and a bigger piston to move more fluid and more braking. .....
Click to expand...

Just so no one is confused a larger bore MC will provide less pressure in the system than one with a smaller bore. But the the larger bore will require less pedal travel to move the same amount of fluid.

For example: Lets say you have a MC with a 1 insq bore and you apply 100 lbs of force onto the MC. You will generate 100 lbs / 1 insq or 100 psi. If you have a MC with a 1/2 insq bore then it would be 100 lbs / .5 insq or 200 psi.
 
That is right......the larger bore will give you a better "pedal feel" while still providing the increased braking you are after.
 
I wouldn't say that a larger bore master will provide less line pressure. I would say that it would require more pedal effort with less pedal travel to achieve the same line pressure than a smaller bore master.


Chuck
 
For the same amount of pedal effort it will produce less line pressure, it's all in the way you look at it.

And, depending on what your definition of "pedal feel" is. To me increased braking with less effort is better "pedal feel". Not really concerned about how far the pedal has to move so my inclination would be to move towards smaller MC bores.
 
dgc333 said:
For the same amount of pedal effort it will produce less line pressure, it's all in the way you look at it.

And, depending on what your definition of "pedal feel" is. To me increased braking with less effort is better "pedal feel". Not really concerned about how far the pedal has to move so my inclination would be to move towards smaller MC bores.
Click to expand...

I also like the pedal feel of the smaller bore master cylinders because they have more pedal travel with less effort.


Chuck
 
I'm the opposite....I like the bigger bore; stiffer, less travel pedal feel.
 
I'm going with the smaller bore M/C...I have the bigger bore now and want more pressure to the pads, so I'll use the smaller bore with more travel to getbetter clamp. The local dirt trackers have been doing this for a while now.
 
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