Lightweight Big Brake Kit

 

The Wilhelm Raceworks big brake kit for the 90-99 Toyota MR2 is designed to provide improved braking performance for track / race use, while keeping weight as low as possible, and most importantly keeping cost reasonable.  Many other kits on the market for MR2 utilize 323mm (12.72") rotors off of the Supra and RX8, and while these are an economical solution, at 21lb for the front and 18lb for the rear, they are HEAVY!  Switching to two piece rotors in those sizes is also very expensive, with rotors starting at about $225, plus the cost of the rotor hat. 

By downsizing slightly to the much more common 12.19" rotor size, rotor prices drop dramatically, with prices starting at around $50 each.  Depending on rotor selection, weight reduction from the rotors alone is 7-8lb per corner compared to a Supra / RX8 based kit.  The rotors are actually about 3lb lighter (each) than stock 93+ MR2 Turbo rotors.  The calipers (including brackets) will drop another ~14lb compared to stock calipers.  The complete brake system weight is nearly identical to 91 MR2 Turbo brakes.  Compared to the larger and heavier 93+ Turbo brakes, the kit saves about 25lb.

The kit uses Wilwood Forged Super Light (FSL) four piston calipers for all four corners plus Wilwood MC4 mechanical parking brake calipers.  Removal of the stock rotor dust shields is required.

Made in the USA!


Complete Big Brake Kit

Big Brake Kit

Front BBK Installed

Rear BBK Installed

 

The complete Wilhelm Raceworks Brake Kit consists of the following parts:

  • Aluminum caliper brackets, front and rear
  • Hardware for attaching the brackets and calipers
  • Four custom made Wilhelm Raceworks aluminum rotor hats
  • Grade 8 bolts, drilled for safety wire, for attaching the rotors to the hats
  • Techna-Fit Steel braided brake lines front and rear
  • Aluminum bracket for parking brake calipers with attachment hardware
  • Custom parking brake cables
  • 2x Wilwood FSL front calipers with 1.38" pistons
  • 2x Wilwood FSL rear calipers with 1.12" pistons
  • 2x Wilwood MC4 mechanical calipers
  • 2x Wilwood HD curved vane front rotors
  • 2x Wilwood HD curved vane rear rotors
  • Wilwood BP20 brake pads, suitable for street and moderate track use.

I strongly recommend also purchasing safety wire and a pair of safety wire pliers to wire the rotor bolts.  You really don't want these coming loose!  The kit that I used is for sale on Amazon.com.  25' of safety wire is enough to do four rotors with some extra for mistakes.

Complete Big Brake Kit
Custom Piston Sizes?

Sorry, international shipping (other than to Canada) is usually prohibitively expensive on a complete brake kit.  For my international customers I recommend purchasing the "Basic Big Brake Kit" found below and finding a local Wilwood dealer to source the rotors, calipers, and pads.

Installation Instructions

The calipers included in the complete kit provide a moderately conservative brake bias to reduce the chances of rear brake lock-up.  If you have an adjustable proportioning valve a larger rear caliper can provide slightly better overall bias.  Please note above if you prefer a different piston size.  Feel free to contact me if you wish to discuss brake bias in more detail.

If you have a favorite brand of brake pads you wish to use, the pads can be eliminated from the kit, or an alternate Wilwood pad can be substituted.  Please contact me to submit a custom order if you would like pads other than the Wilwood BP20.

The slightly lighter weight and less expensive Wilwood Ultralight rotors or the slotted GT versions of the standard HD rotors are also available as a custom order.

Note: The calipers, rotors, and pads ship directly from Wilwood and will arrive separately from the rest of the parts.


Basic Big Brake Kit

If you prefer to purchase the rotors, calipers, and pads yourself, the basic kit consists of the following parts.  This is usually the best option for international customers.

  • Aluminum caliper brackets, front and rear
  • Hardware for attaching the brackets and calipers
  • Four custom made Wilhelm Raceworks aluminum rotor hats
  • Grade 8 bolts, drilled for safety wire, for attaching the rotors to the hats
  • Techna-Fit Steel braided brake lines front and rear
  • Aluminum bracket for parking brake calipers with attachment hardware
  • Custom parking brake cables
Basic Big Brake Kit

To complete your brake setup you will also need to purchase or already have:

  • 2x Wilwood FSL calipers for front
  • 2x Wilwood FSL calipers for rear
  • 2x Wilwood MC4 mechanical calipers
  • 2x 12.19" x 1.25" rotors with 8x7.00" bolt pattern
  • 2x 12.19" x .81 rotors with 8x7.00" bolt pattern
  • 2x Brake pad set for Wilwood FSL calipers

Approximate cost for these items should be $1250-$1450 for a full front / rear setup with parking brake, depending on where you buy them and your choice of rotors and pads. 

Installation Instructions

I strongly recommend also purchasing safety wire and a pair of safety wire pliers to wire the rotor bolts.  You really don't want these coming loose!   The kit that I used is for sale on Amazon.com.  25' of safety wire is enough to do four rotors with some extra for mistakes.


Individual Parts

Rotor Hats

Designed specifically for the MKII Toyota MR2, Wilhelm Raceworks rotor hats are machined from 6061-T6 aluminum and black anodized.  Included with the complete kit, and offered separately for those looking for a way to upgrade an existing brake kit to two-piece rotors. Alternate caliper spacers may be required.  The hat offset (hub surface to face of rotor) is .41" front / .86" rear.

Sold by the pair, includes drilled head rotor mounting bolts:

Rotor Hats

 

Brake Lines

By popular demand, I am offering the steel braided brake lines from the kit separately as well.  Steel braided, PTFE lined, with a black nylon cover and a 90° fitting on the caliper end, these brake lines are made in the USA by Techna-Fit to my specifications.  Designed specifically for use with Wilwood calipers on the MKII MR2 chassis.  They might be suitable with other aftermarket calipers with a 1/8" NPT inlet fitting.  NOT for use with stock calipers.

Brake Lines
 

Technical Info

Rotors

This kit can use virtually any 12.19" rotor with an 8x7.00" bolt pattern, 1.25" thickness for the front and .81" thickness for the rear.  There are numerous options from various manufacturers including Wilwood, Afco, Colman Racing, and many others.  They are available with straight vanes, pillar vanes, or curved vanes, and slotted, cross drilled, or both.  A few options are shown in the chart below.  There are many others on the market as well.  Be sure to purchase one right and one left if buying curved vane rotors!

 

Front Rotors (12.19"x1.25")
Brand / Model LH Part # RH Part # Vane Style Price Weight
 Wilwood HD48  160-11836  160-11835  Curved  $99  12.7lb
 Wilwood Ultralight  160-2895 160-2894  Curved  $65  10.5lb
 Afco Pillar Vane  6640103    Pillar  $50  10.9lb
 
Rear Rotors (12.19"x.81")
Wilwood HD36 160-12290 160-12289 Curved $99 9.5lb
Wilwood Ultralight  160-0277   Straight $33 8.9lb
Afco Pillar Vane  6640102   Pillar $50 8.4lb

 

The Wilwood rotors are typically cheapest from Summit Racing.  You can browse the rest of their rotor offerings (drilled, slotted, etc) at Wilwood.com. The Afco rotors can be purchased directly from their site at Afcodynapro.com.  They also have slotted and drilled versions available.  I run the Wilwood HD curved vane rotors front and rear on my car.  I have not tried any of the other options.

 

Calipers

Caliper choice is important to optimize brake bias for maximum braking potential, while minimizing the chance of locking the rear brakes before the fronts.

For MR2s equipped with the non-turbo brake proportioning valve, front calipers with 1.38" pistons and rears with 1.25" pistons will provide optimal brake bias for most street cars with street tires and street pads.   However, this combination may require an adjustable proportioning valve for use with high friction race pads and / or high grip race tires.  For those looking for a less aggressive setup or who don't want to bother with an adjustable proportioning valve, the 1.12" piston calipers for the rear will provide a more forward biased setup.

For those with the turbo proportioning valve the 1.38" / 1.12" caliper combination will provide optimal bias at about 1g deceleration.  Again, high grip race tires and high friction pads may require an adjustable proportioning valve.

More details on brake bias and the effects of various caliper / pad / proportioning valve combinations can be found on my Brake Bias page.  Please contact me if you have questions about choosing calipers for your setup.

Recommended Wilwood FSL Calipers
Piston Diameter Rotor Width Part # Notes
1.38" 1.25" 120-11130 Front
1.25" .81" 120-11126 Rear with NA proportioning valve.  Adjustable proportioning valve may be required for race use.
1.12" .81" 120-11125 Rear with Turbo proportioning valve. 

 

Another caliper option is to use the 1.62" calipers in the front, paired with either the 1.38" in the rear for those with the NA proportioning valve, or the 1.25" in the rear with the turbo proportioning valve.  This setup is a bit more conservative than the setup above, but should provide good performance.  It will also reduce overall brake system pressure.  This may also be an option for those who already have a set of calipers they want to use.  Part numbers for this option are listed below.

Alternate Wilwood FSL Calipers
Piston Diameter Rotor Width Part # Notes
1.62" 1.25" 120-11133 Front
1.38" .81" 120-11128 Rear with NA proportioning valve.  Adjustable proportioning valve may be required for race use.
1.25" .81" 120-11126 Rear with Turbo proportioning valve.

More details on the Wilwood FSL calipers can be found on Wilwood's website.

 

The parking caliper used with the kit is the Wilwood MC4.   One of each LH/RH is required.

   Wilwood MC4 Parking Calipers
LH Part #  120-12070-BK
RH Part #  120-12069-BK

More information on Wilwood's website.  The part numbers above are the black powdercoated version, which is the best match to the FSL main calipers.  Red and silver are also available.

As with the rotors Summit Racing is often the cheapest and easiest place to buy calipers, but there are other places to buy them as well.

 

Brake Pads

Many companies make pads in many different compounds for the Wilwood FSL caliper, including but not limited to: Wilwood, Porterfield, Performance Friction, Hawk, Raybestos, etc.  The pad shape is #7420, and the kit is designed to use the 20mm thick pads.  Information and part numbers for the various Wilwood compounds can be found here.  Summit Racing has the Wilwood pads at a good price.  For other manufacturers, TopBrakes.com has a good selection at good prices.

 

Custom Parts / Clearances

The Wilhelm Raceworks hats and main caliper brackets in this kit are machined from 6061-T6 aluminum, and black anodized.  All are designed around the brake torque required for 1.4g deceleration, and with a factor of safety of 2x on the 500 million cycle fatigue strength of 6061-T6 aluminum.

The parking brake system in this kit is capable of achieving deceleration rates of ~.3g.  More than enough to pass the emergency brake function tests that I am aware of.  However, it is ultimately designed and intended to be a parking brake, or for that once-in-a-lifetime emergency situation.  If you are drifting or doing hand-brake turns, you may find it to be insufficient.

The front calipers sit about 1/8" closer to the wheel than they do on the typical Supra rotor based kit.

Assuming adequate spoke to caliper clearance, most 16" wheels should fit over the front brakes without issue.  The parking caliper in the rear might cause an issue with some 16" wheels.  Use the template below to check fit on your wheels before ordering.

Caliper Clearance Template