Brake Conversions
VL Turbo Commodore Calipers
and Mitsubishi Verada Discs
Disclaimer: This brake conversion is not approved
for use on public roads. Fitment of the brakes mentioned herein may render the
vehicle unroadworthy, void any insurance policy on the vehicle or driver and
disqualify the vehicle from some racing classes. Zac Campbell and the Adelaide
1600 Club will not be held responsible for damage or loss of any kind as a
result of fitment of these brakes. There has not been any discussion as to the
steps to be undertaken in order to obtain approval from governing or insuring
bodies as the rules vary according to local jurisdiction. Sorry about all
that, but it’s just got to be there !
The brakes used here are 276mm by 24mm thick vented
rotors from a Mitsubishi Verada and finned alloy single-piston semi-floating
calipers from a VL Turbo Holden Commodore. The calipers were selected first,
because of their easy fitment to 1600 and 180B struts, once the struts were
swapped from left to right to position the caliper forward of the strut.
Careful measurement provided the offset and diameter of rotor required, and
the DBA downloadable catalogue was scoured looking for likely candidates – the
Mitsubishi Verada unit being very close to the money (DBA 425/426).
Unfortunately, the hole placement on the factory Verada rotors means one of
the 4 mounting holes to fit the rotor to the 180B hub always breaches an
existing hole. Blanks were duly ordered, the centre holes enlarged from 69 to
73mm and the 4 mounting holes drilled – all for a bit less than buying the
standard units from a retailer, cool!
When it came time to fit it all up it became
apparent a shim would be needed to position the calipers over the rotors
correctly – 1.5mm thick surface ground washers (4) were made up (parallel
sides so they bolt up flat) with the holes reamed to fit the bolt shoulders.
You can shim calipers one way, but not the other, obviously, so the rotors
were chosen with that in mind. Brazing the washers to the caliper brackets
keeps them in place during pad changes and maintenance.
The standard VL Turbo flexible brake hose was used
because of its block-mounting on the caliper (see photo). This comes close to
the swaybar at full steering lock when the outside wheel drops into a pothole
or something, so the block-mount is mandatory for clearance and safety.
Clearance between lower control arm and the rotor is minimal at full bump, and
would be a real problem on a severely dumped 1600. Using backing plates on
these brakes is not an option. Under the 15” wheels of the test-car there’s
plenty of room (see photo) and some 14” alloys will fit over them too.
The new calipers have a larger piston area then the
stock units, so attention was paid to the master cylinder arrangement and
biasing of the rear brakes. Being single piston calipers, a booster would be a
good upgrade – the unboosted pedal still needs to be shoved firmly to get the
brakes’ attention, but there’s no sign of the usual 1600 brake fade after a
few hard stops – quite the opposite, they only get better with a bit of heat.
The extra 2kg+ hanging off each wheel isn’t real
handy, but hey, you just can’t have it all!
