Hat Features:
GT Series Fixed Mount Rotor Hats are engineered to withstand the rigors and demands of extreme motorsports competition. Each hat is precision machined from premium grade aluminum offering high strength with low unsprung and rotating weight. Hats in this category normally feature a threaded hole design for traditional use with standard through-hole mount vented iron rotors. Some hats in this category may also be used with dynamic mount, lightweight steel rotors that are specially slotted for use with T-nut bolt kits. In all possible cases, raised blot bosses and/or scallops between the rotor mount lugs provide additional air circulation to assist with cooling. All GT series hats are black anodized for oxidation resistance and carry Wilwood's signature logo. When used in conjunction with matched Wilwood rotor hardware kits, these hats provide solid, reliable performance under the most extreme conditions.

Shallow Offset Hats provide solid rotor mounting in extreme narrow space applications with offsets that are often less than 1.00". There are sizes offered for nearly every available rotor mount pattern.

Straight Bell Hats are typically used with rotor patterns based on the 6.75" and 7.00" diameter rotor mount circles. They are available in a variety of offsets for use with all types of rotors from 11.75" to 13.00" overall diameter.

Flared Bell Hats are typically used with rotor patterns based on mount circles of 8.38" and larger. They are available in a variety of offsets and used with all types of rotors with diameters of 12.19" and larger.

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View Technical Drawing

View Technical Drawing

View Technical Drawing

Rotor Bolt Circle

Wheel Lug Pattern

Hat Offset

Stud Hole Diameter

Center Hole I.D.

Face Thickness

Clearence I.D.

Mount Hole

Hat Part Number

Rotor Bolt Kit Number

12 x 10.75"

8 x 6.50"

1.55"

.625"

4.64"

.45"

7.85"

5/16-18

170-8878

230-9068

12 x 10.75"

8 x 5.50"

.813"

.625"

3.09"

.45"

7.21"

5/16-18

170-8960

230-8960

12 x 10.75"

8 x 5.32"

1.11"

.591"

3.42"

.25"

7.05"

5/16-18

170-9066

230-9068

12 x 9.18"

5 x 4.75"

0.41"

.52"

2.78"

.30"

8.14"

1/4-20

170-8073

230-4572

12 x 8.75"

5 x 5.00"

3.00"

.64"

3.06"

.25"

6.40"

1/4-20

170-4767

230-4572

12 x 8.75"

5 x 5.00"

2.25"

.64"

3.06"

.25"

6.40"

1/4-20

170-4568

230-4572

12 x 8.75"

5 x 5.00"

2.12"

.64"

3.06"

.25"

6.40"

1/4-20

170-4844

230-4572

12 x 8.75"

5 x 5.00"

1.88"

.64"

3.06"

.25"

6.40"

1/4-20

170-5261

230-4572

12 x 8.75"

5 x 5.00"

1.50"

.64"

3.06"

.25"

6.40"

1/4-20

170-5429

230-4572

12 x 8.75"

5 x 4.75"

.672"

.52"

2.78"

.25"

7.10"

1/4-28

170-8169

230-8217

12 x 8.75"

5 x 4.75"

1.20"

.52"

3.00"

.25"

6.93"

1/4-20

170-8883

230-4572

12 x 8.75"

5 x 4.75"

0.88"

.52"

2.78"

.30"

7.13"

1/4-20

170-6837

230-4572

12 x 8.75"

5 x 3.93"

0.71"

.52"

2.17"

.30"

7.49"

1/4-20

170-9011

230-4572

12 x 8.75"

5 x 4.75"

0.57"

.52"

2.78"

.30"

7.37"

1/4-20

170-7177

230-4572

12 x 8.75"

5 x 4.75"

0.41"

.52"

2.78"

.30"

7.72"

1/4-20

170-8132

230-4572

12 x 8.75"

5 x 4.75"

0.29"

.52"

2.78"

.30"

7.73"

1/4-20

170-8919

230-4572

12 x 8.75"

5 x 4.75"

0.56"

.52"

3.12"

.29"

7.75"

1/4-20

170-8815

230-4572

12 x 8.75"

5 x 4.72"

1.00"

.67"

2.82"

.39"

7.75"

1/4-20

170-8757

230-4572

12 x 8.75"

5 x 4.50/4.75"

2.00"

.52"

3.06"

.25"

6.40"

1/4-20

170-7038

230-4572

12 x 8.75"

5 x 4.50/4.75"

1.88"

.52"

3.06"

.25"

6.40"

1/4-20

170-6994

230-4572

12 x 8.75"

5 x 4.50/4.75"

1.75"

.52"

3.06"

.25"

6.40"

1/4-20

170-7467

230-4572

12 x 8.75"

5 x 4.50"

0.81"

.52"

3.06"

.25"

7.25"

1/4-20

170-6126

230-4572

12 x 8.75"

5 x 4.50"

0.75"

.52"

2.69"

.38"

7.25"

1/4-20

170-9294

230-4572

12 x 8.75"

5 x 4.50"

0.72"

.52"

2.80"

.31"

6.30"

1/4-20

170-9128

230-4572

12 x 8.75"

5 x 4.50"

0.64"

.58"

2.80"

.31"

6.30"

1/4-20

170-9128

230-4572

12 x 8.75"

5 x 4.50"

0.54"

.52"

2.69"

.38"

7.25"

1/4-20

170-9289

230-4572

12 x 8.75"

5 x 4.50"

0.41"

.58"

2.80"

.27"

7.75"

1/4-20

170-6223

230-4572

12 x 8.75"

5 x 4.50"

0.21"

.52"

2.72"

.25"

8.01"

1/4-20

170-9558

230-4572

12 x 8.75"

5 x 3.94"

1.10"

.52"

2.29"

.27"

7.02"

1/4-20

170-6990

230-4572

12 x 8.75"

4 x 4.25"

0.81"

.52"

3.06"

.25"

7.25"

1/4-20

170-6157

230-4572

12 x 8.75"

4 x 3.93"

0.60"

.52"

2.17"

.25"

7.49"

1/4-20

170-8357

230-4572

12 x 8.38"

5 x 5.00"

2.25"

.64"

3.06"

.25"

6.40"

1/4-20

170-4694

230-4572

12 x 8.38"

5 x 5.00"

2.12"

.64"

3.06"

.25"

6.40"

1/4-20

170-4843

230-4572

12 x 8.38"

5 x 5.00"

1.88"

.64"

3.06"

.25"

6.40"

1/4-20

170-5260

230-4572

12 x 7.06"

5 x 4.75"

0.25"

.52"

2.78"

.30"

6.18"

1/4-20

170-7746

230-8008

12 x 7.00"

5 x 5.00"

2.12"

.64"

3.06"

.25"

6.40"

1/4-20

170-4847

230-4572

12 x 7.00"

5 x 4.75

0.81"

.52"

2.78"

.30"

6.00"

1/4-20

170-8492

230-4572

12 x 7.00"

5 x 4.50/4.75"

2.01"

.54"

2.66"

.25"

5.93"

1/4-20

170-9321

230-4572

12 x 7.00"

5 x 4.50"

0.35"

.58"

2.80"

.27"

6.19"

1/4-20

170-8588

230-8008

12 x 7.00"

5 x 4.50"

0.21"

.52"

2.72"

.25"

6.22"

1/4-20

170-8750

230-8008

12 x 6.75"

5 x 5.00"

2.12"

.64"

3.06"

.25"

6.12"

1/4-20

170-3788

230-3319

12 x 6.50"

5 x 4.50"

0.75"

.52"

3.11"

.29"

5.84"

1/4-20

170-8687

230-8008

8 x 8.50"

5 x 5.00"

3.00"

.64"

3.06"

.25"

6.40"

1/4-20

170-5589

230-4609

8 x 8.50"

5 x 5.00"

2.50"

.64"

3.06"

.25"

6.40"

1/4-20

170-5588

230-4609

8 x 8.50"

5 x 5.00"

2.12"

.64"

3.06"

.25"

6.40"

1/4-20

170-4580

230-4609

8 x 7.00"

5 x 5.00"

2.50"

.64"

3.06"

.25"

6.64"

5/16-18

170-2751

230-2589

8 x 7.00"

5 x 5.00"

2.12"

.64"

3.06"

.25"

6.64"

5/16-18

170-2522

230-2589

8 x 7.00"

5 x 4.75"

0.88"

.52"

2.78"

.30"

6.00"

5/16-18

170-8493

230-8390

8 x 7.00"

5 x 4.50/4.75"

1.43"

.52"

3.00"

.25"

6.04"

5/16-18

170-7632

230-3484

8 x 7.00"

5 x 4.50"

1.05"

.58"

2.78"

.28"

6.02"

5/16-18

170-8589

230-8390

8 x 7.00"

5 x 4.50"

0.94"

.50"

2.66"

.24"

5.90"

5/16-18

170-8320

230-8390

8 x 7.00"

5 x 4.50"

0.72"

.50"

2.53"

.25"

5.90"

5/16-18

170-6947

230-8390

8 x 7.00"

5 x 4.38"

1.01"

.45"

3.25"

.25"

5.88"

5/16-18

170-8386

230-8390

8 x 7.00"

5 x 3.94"

1.09"

.52"

2.28"

.27"

5.27"

5/16-18

170-9206

230-8390

8 x 7.00"

5 x 3.93"

0.77"

.50"

2.30"

.32"

5.90"

5/16-18

170-8324

230-8390

8 x 7.00"

5 x 3.93"

0.50"

.55"

2.40"

.25"

5.90"

5/16-18

170-6378

230-8390

8 x 7.00"

5 x 3.93"

0.41"

.58"

2.56"

.25"

5.90"

5/16-18

170-8269

230-8390

8 x 7.00"

4 x 4.50"

0.72"

.50"

2.72"

.25"

5.90"

5/16-18

170-6996

230-8390

8 x 7.00"

4 x 3.93"

1.16"

.50"

2.53"

.25"

5.90"

5/16-18

170-8405

230-8390

8 x 7.00"

4 x 3.93"

0.83"

.52"

2.53"

.26"

5.90"

5/16-18

170-8645

230-8390

8 x 7.00"

4 x 3.93"

0.45"

.50"

2.53"

.25"

5.90"

5/16-18

170-6288

230-8390

8 x 7.00"

Undrilled

0.72"

N/A

2.40"

.25"

5.90"

5/16-18

171-7671

230-8390

8 x 7.00"

Undrilled

1.22"

N/A

2.17"

.26"

6.40"

5/16-18

171-8976

230-8390

6 x 6.25"

4 x 3.93"

0.66"

.50"

2.53"

.32"

5.60"

5/16-18

170-8643

230-8991

6 x 6.25"

Undrilled

0.77"

N/A

2.17"

.32"

5.60"

5/16-18

171-8975

230-8991