Irs; Miscellaneous Brake Information - Factory Five Racing MK4 ROADSTER Assembly Manual

Rotor OEM 94-98 Mustang Cobra™ 11.65" rotor
Caliper OEM 94-98 Mustang Cobra™ single piston 1.4375" caliper
FFR 11.65" Caliper mount brackets (FFR#14571, 14572)
Bracket

IRS

Master Cylinder – FFR

The rear discs are 5-lug, so vehicles need to have the front rotors converted to 5-lug to match.

Front rotors from a '91 Lincoln Mark VII can be used. The rotors bolt right on to the 87-93 front
spindle, and use the 87-93 Mustang caliper.

Thunderbird Super Coupe 5-lug rear brakes have a 4.25" bolt circle where as the Mustang 5-lug
bolt pattern uses a 4.5" bolt circle. The IRS hubs need to be drilled to the Mustang pattern or
1999-2004 Mustang Cobra™ IRS hubs can be used. FFR supplies new studs with the IRS kit.
11.65" Rear
Factory Five 11.65" IRS Brakes (FFR#14778)
12.19" Rear
Factory Five Wilwood IRS Brakes

Miscellaneous Brake Information

The caliper from the 1984 Lincoln Town Car or 1992 Lincoln Mk 7 will bolt on to the Mustang spindle
although the piston is 73mm in diameter, so it would not be well suited for the recommended brake
setups above. If this caliper is used, a 1" master cylinder from a '93 Mustang Cobra™, 84-86 Mustang
SVO or Bendix # 12669, although this is not an ideal setup.
If you desire a dual master cylinder set up (having individual master cylinders for the front and rear), the
following information will help with those installations:
There are several different versions on the market. Dual master cylinder units usually use a balance bar
to proportion the amount of line pressures from the front to rear, so no proportioning valve is necessary.
We have used a unit from CNC brakes (part # 241). This unit uses the Mustang bolt pattern, so it will
simply bolt to the FFR foot box. Use the following table to determine each master cylinder required.
" Master cylinder/Proportioning valve (FFR#14739)
15 /
16
Caliper Piston
2
Area (in )
Up to 3.6
3.6 to 4.2
4.2 to 4.5
4.5 to 4.7
4.7 to 5.5
5.5 to 5.9
5.9 to 6.3
516
www.factoryfive.com
Master Cylinder
Bore Diameter
(in)
⅝
7
/
10
¾
13
/
16
⅞
15
/
16
1
508-291-3443