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Re: Four wheel disc brakes?

To: triumphs@autox.team.net
Subject: Re: Four wheel disc brakes?
From: rgb@exact.com
Date: Sat, 1 May 11:59:59 1999

>update a TR4-TR6 to have 4 wheel disc brakes

I am certain its possible, but I would have to question "why"?  see below.

>From my experience driving multiple TR6's, many of the TR6's are
extremely un-street worthy, i.e. death traps.   Is yours?   If you
cannot answer that you KNOW the condition of the following items,
then you shouldn't be on the the roads - any road.

>way many people drive now days, I would like the additional stopping

I agree, the modern roads are high speed, fast paced, with no margin
for driver error or mechanical malfunction...

So, the goal is more stopping power on a TR6?   Then, the rear brakes
would be the last item to consider.   Its a front heavy car with huge
discs designed in already, these should be optimized.  Oh, and do not
forget the most important piece ---  the tires.
(new 3400lb Mustang V8's have 11" rotors, 2400lb TR6 has 10.75" rotors)

I will attempt to itemize in order the items to apply

1.  verify the front braking system is perfect, likely SS caliper pistons
    to rid yourself of those rusted pits and rebuilt hydraulics (I run
    DOT 5 to make certain the seals always work after sitting)
2.  new brake hoses on the front
3.  new front discs, these are 1/2" thick and work great when fresh, they
    loose the ability to disipate heat as they thin... just replace them
4.  HP front disc pads, I use TRF's brand (HP pads and new discs will really
    fix the stopping)
5.  Front end bushings, sway bar mountings, shocks, steering all perfect
    (I only use poly or nylon bushings)

At this point, you've fixed the brake problems, up the ladder we go.

6a. OEM redlines, throw these as far as you can, these rubber donuts
    are not up to modern roads.   I've spun several cars on these,
    even brand "new" ones, its a 60's design made of 60's materials
    (prior to putting a man on the moon, or microprocessors)  OBSOLETE!
    These tires are useful for parades and Concours ONLY.   In fact for
    concours the rule book states that an accepted replacement tire is
    acceptable (a very questionable area, but in theory they cannot deduct
    for 205/70 tires, I like the Michelin 205VR70-15, these have stiff
    sidewalls and work well on stock rims, the rims better be straight)
6b. Mag wheels, buy those 15x7 zero offset Panasports and some 215VR65-15
    tires, this provides a massive footprint, holds the tire patch level
    and "looks" vintage.  Forget the 6" width, buy the 7" (confirm 5 above).

NOW TO THE MOST important item

8.  rear brake lights - all modern cars have 3 huge bright lights, I
    will contend that this places you at a disadvantage, 2 little faint
    bulbs just don't cut it, Bubba doesn't even hit the brake pedal, if
    you've done the above item, you can stop faster than Bubba's truck!

Now to the rear  (10 and 11 are racing mods)

8.  rebuild all rear, shocks, bushings, etc to keep it in control
9.  New shoes, all brake parts in excellent shape
10. Larger rear wheel cylinders, note the 76 cars went from .70 -> .75
    pistons for better stopping, also used a different emergency brake
    leverage to make this better.   Racers fit 7/8" rear Datson pistons
    for even more rear brakes
11. Fit 240/260/280Z rear aluminum drums (slight machining) to increase
    the cooling back there.


--
Roger G. Bolick, rgb@exact.com 512-794-9567, FAX 512-345-2879

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