|
3rd Generation RX-7 Installation
photos
On June 6, 2004,
Zeckhausen Racing installed a custom StopTech front brake kit on a 1993 RX-7
track car. The kit used 4-piston ST-40 calipers and floating 332mm x
32mm AeroRotors.
Custom StopTech front kit with 34/36mm caliper pistons
Custom caliper
piston sizing of 34/36mm was used, instead of the standard 30/36mm sizing,
because this race car has larger rear brakes transplanted from the 1999
Japanese model RX-7. In order to provide proper front/rear brake
balance, larger pistons were required in the StopTech calipers.
Upgraded rear brakes - 1999 RX-7 (Japanese Model)
The components
required to upgrade to the larger 1999 Japanese RX-7 brakes are available
from Mazda Competition for
approximately $750 if you are a member. See their website for
membership and ordering details.
If you have
upgraded your rear brakes and wish to install StopTech front brakes, you
should order StopTech p/n 87-546-4600. The standard StopTech
front brake kit (p/n 83-546-4600) is sized to work with the smaller 1993-1995 rear brakes. The
"87" in the first two digits of the part number specifies "race only"
since the kit uses anti-knockback springs behind the caliper pistons.
This kit may be driven on the street, but there may be some slight brake
drag induced by the springs. If there is a long period between track
events, you may wish to pull the caliper pistons and remove the springs for
street use, then reinstall them before the track event. All
StopTech kits with parts numbers starting with "87" are sold without brake
pads. If you wish to use these brakes on the street, you will
need to order street pads (typically Axxis Ultimate) in addition to race
pads.
Custom backing plate and brake cooling ducts
This RX-7 had
custom backing plates, with a flexible duct routed from the front of the
car, to force cool air through the rotors. The StopTech kit bolted
right on with no interference.
Important note:
The StopTech kit uses the factory caliper mounting bolts to hold the adapter
bracket in place. If your RX-7 has a custom brake kit installed
already that uses DIFFERENT hardware to hold the calipers in place, you will
need to either find the original caliper bolts in that box at the back of
your garage, or you will need to purchase new bolts from your Mazda parts
source. The RX-7 pictured above had larger diameter Coleman rotors and
an adapter plate which relocated the stock calipers in order to fit the
bigger rotors. This arrangement did not use the factory caliper bolts,
so new ones had to be located before we could begin the installation.
Pads
and StopTech stiffening bridge installed
Bleeding the
brakes was a snap. Unlike the Nissan 350Z, which requires the calipers
to be tilted forward for the initial bleed, the RX-7 kit positions the
calipers completely vertical so the bleed screws are at the top and air
bubbles easily migrate out. Still, I followed all the best practices
documented on my brake bleeding page.
Tapping the calipers with a rubber mallet only yielded a couple of tiny
bubbles, but it's better to have them in the catch bottle than in the
caliper!
|
