DANMAS wrote:
>
> Andy,
>
> A subject very similar to this came up last year on the Triumph list, and
> generated a great deal of heated debate. I'm sure my response will generate
> another round, but I must respond. If one installs a set of disk brakes into
> the rear of a Spitfire, I believe one is left with three alternatives:
>
> 1) Upgrade the front brakes to maintain the front to rear brake bias,
>
> 2) Add proportioning valve in the brake line to the rear to reduce the braking
> power to approximately the same as with the original drum brakes, or,
>
> 3) Get your affairs in order and prepare to die.
>
> Manufacturers spend a great deal of engineering time to balance the braking
> system front to rear to prevent the rear brakes from locking up before the
> front brakes do. If the rears lock up first in a panic stop, the rear end has
> the unfortunate tendency of trading places with the front of the car. It is
> extremely difficult to control the direction of travel when you are looking
> where you've been. There is a great deal more to it than that, but you get
> the idea.
>
> I am not a brake engineer, but I have been doing a lot of research on this
> subject for my TR6/Ford 302 project. By default, I wound up with 11 X 2 inch
> drum brakes on the rear in place of the factory 9 X 1 3/4 inch drums. I am now
> looking into option 1 or 2 (option 1 is preferable, option 3 is not
> acceptable). Before taking my word for it, I recommend reading one of the
> many books avialable with this type information. In particular, I recommend
> "Brake Handbook" by Fred Puhn, HP books, ISBN 0-89586-232-8.
>
> I don't know of any other readily available books just on brakes, but many of
> the Street Rod or Hot Rod publications have material on this subject, and it
> comes up often in the various rodding magazines. Without exception, the
> articles warn against letting the rears lock up first.
>
> Dan Masters,
> Alcoa, TN
>
> '71 TR6---------3000mile/year driver, fully restored
> '71 TR6---------undergoing full restoration and Ford 5.0 V8 insertion - see:
> http://www.sky.net/~boballen/mg/Masters/
> '74 MGBGT---3000mile/year driver, original condition - slated for a V8 soon
> '68 MGBGT---organ donor for the '74
Henry Ford had some interesting reading on this for his "A", if the rear
brakes first the car is coming over or around, the front must grab first
and then the rear but more pressure must be on the front, there is a
seperate set of brake shoes on the rear for the emergency brakes, Datsun
copied this starting with their 240 series anmd still uses it in some
models today.
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