Big Brake Kit

Big Brake Kit

Big Brake Kit Big Brake Kit
Price : 1129 USDIn stock

Wilhelm Raceworks Big Brake Kit for the SW20 MR2 is he perfect balance of all the stopping power you will ever need, plus weight savings.Built around two piece 12.19" rotors the kit saves 7-8lb per corner (~30lb total) compared to a kit based on Supra / RX8 rotors when equipped with Superlite calipers and HD/GT rotors. The complete brake system weight is nearly identical to stock 91/92 brakes, and about 25lb lighter than 93+ brakes.

For a more budget friendly and lighter weight option, Forged Narrow Dynalite calipers and Ultralite rotors save an additional 10lb. Or mix and match to suite your needs.

The kit uses Wilwood Forged Superlite (FSL) or Forged Narrow Dynalite (FNDL) 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!

Installation Instructions

For those looking for a more budget friendly and even lighter weight option choose the Wilwood Forged Narrow Dynalite calipers and Wilwood Ultralite rotors. The calipers and pads are slightly smaller, and the rotors are lighter weight. Not only does this save you some money, it saves an additional 10 lb off the brake system weight. Suitable for street, autocross, and occasional track use. If you are building a serious track car I recommend the FSL calipers and HD or GT rotors.

Additional Notes (Click Here)
  • The Wilwood BP20 pads will handle quite a lot of track abuse in my experience, but they can be a little noisy when cold. The BP10 is more street friendly. Other pads are also available. Please contact me if you wish to discuss substituting alternate pads. For a serious track car, true race pads are recommended.
  • For those looking for extra front wheel clearance, I can also substitute the thinner rear rotors and hats for the normal fronts, along with a narrower front caliper. This will save you ~0.44in (11mm) of caliper to spoke clearance. Please leave me a note in the checkout if you would like this option (cost is the same as a normal front kit)
  • The standard calipers included in the complete kit provide a moderately conservative brake bias with the NA proportioning valve, and a more aggressive bias with the Turbo valve. If you have an adjustable proportioning valve, larger rear calipers will provide better overall bias. Feel free to contact me if you wish to discuss brake bias in more detail.
  • Red or black powder coated calipers are special order items and will take an extra 3-4 weeks to deliver.
  • The calipers, rotors, and pads ship directly from a distributor and will arrive separately from the rest of the parts.
  • The calipers available for this kit do not include dust seals. This can be a problem for passing inspections in some locations.
  • The HD or GT rotors are generally recommended for heavy track use. The Ultralite rotors will work, but may need to be replaced more frequently.
  • The Forged Narrow Dynalite caliper is unique among Wilwood calipers in that it has a raised logo, and when ordered with powder coating the logo is not laser engraved. If you would prefer the silver logo like other Wilwood calipers chose the machined logo option. Otherwise the raised logo will be the same color as the rest of the caliper. Gray anodized calipers will come with the machined silver logo as shown in the pictures.
Additional Technical Info (Click Here)


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 or curved vanes, and slotted, cross drilled, or both. The Wilwood 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")
ModelLH Part # RH Part #Vane Style Price Weight
Wilwood GT48 (slotted)160-11840160-11839Curved$15312.7lb
Wilwood HD48160-11836160-11835Curved$13712.7lb
Wilwood Ultralight160-2895160-2894Curved$8210.5lb

Rear Rotors (12.19"x.81")
Wilwood GT36 (slotted)160-12292160-12291Curved$1379.5lb
Wilwood HD36160-12290160-12289Curved$1149.5lb
Wilwood Ultralight160-0277Straight$438.9lb


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, the standard 1.38" / 1.12" calipers provide a slightly conservative bias.

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

When an adjustable proportioning valve is used, increasing the rear piston size to 1.25" will produce better bias over a wider range of deceleration rates.

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. Note: FSL = Forged Superlite, FNDL = Forged Narrow Dynalite

Recommended Wilwood Calipers
Part #Piston
FSL120-111301.38"1.25"FrontStandard piston sizes supplied with kits.
FSL120-111261.25".81"RearAdjustable proportioning valve recommended.
FSL120-111251.12".81"RearStandard piston size supplied with kits.
Optimal with NA proportioning valve.
Slightly aggressive bias with turbo proportioning valve.

Another caliper option is to use the 1.62" calipers in the front, paired with either the 1.38" or the 1.25" in the rear. The 1.25" piston setup is a bit more conservative than the setup above, but should provide good performance. It will also reduce overall brake system pressure. An adjustable proportioning valve is recommended for the 1.38" rear option. 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 Calipers
Part #Piston
FSL120-111281.38".81"RearAdjustable proportioning valve strongly recommended.

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

The part numbers above are the black powdercoated version. Red and silver are also available.

Brake Pads

Many companies make pads in many different compounds for the Wilwood FSL caliper, including but not limited to: Wilwood, Stoptech, Porterfield, Performance Friction, Hawk, Raybestos, etc. The Wilwood pad shape for the FSL calipers or the Stoptech ST43 is #7420, and for the FNDL is #7816.

Custom Parts

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 these kits 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.

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.

Forged Superlite Caliper Clearance Template

Forged Narrow Dynalite Caliper Clearance Template

Caliper Option
Wilwood Forged Superlite (0)
Wilwood Forged Narrow Dynalite (-80)
Caliper Color
Larger 1.25" Pistons for adjustable prop-valve?
Yes (0)
Machined Logo
Yes (60)
Rotor Options
Brake Pads
Add Parking Brake?
Yes (450)
Big Brake Kit
Big Brake Kit
Big Brake Kit