11mm Overdrive Chart
Percentage of Crankshaft Speed
Blower Spocket Tooth Count
C
r
a
n
k

S
p
r
o
c
k
e
t

T
o
o
t
h

C
o
u
n
t
43
42
41
40
39
38
37
36
35
34
33
32
31
30
29
28
27
26
25
49
14.0
16.7
19.5
22.5
25.6
28.9
32.4
36.1
40.0
44.1
48.5
53.1
58.1
63.3
69.0
75.0
81.5
88.5
96.0
50
16.3
19.0
22.0
25.0
28.2
31.6
35.1
38.9
42.9
47.1
51.5
56.3
61.3
66.7
72.4
78.6
85.2
92.3
100.0
51
18.6
21.4
24.4
27.5
30.8
34.2
37.8
41.7
45.7
50.0
54.5
59.4
64.5
70.0
75.9
82.1
88.9
96.2
104.0
52
20.9
23.8
26.8
30.0
33.3
36.8
40.5
44.4
48.6
52.9
57.6
62.5
67.7
73.3
79.3
85.7
92.6
100.0
108.0
53
23.3
26.2
29.3
32.5
35.9
39.5
43.2
47.2
51.4
55.9
60.6
65.6
71.0
76.7
82.8
89.3
96.3
103.8
112.0
54
25.6
28.6
31.7
35.0
38.5
42.1
45.9
50.0
54.3
58.8
63.6
68.8
74.2
80.0
86.2
92.9
100.0
107.7
116.0
55
27.9
31.0
34.1
37.5
41.0
44.7
48.6
52.8
57.1
61.8
66.7
71.9
77.4
83.3
89.7
96.4
103.7
111.5
120.0
56
30.2
33.3
36.6
40.0
43.6
47.4
51.4
55.6
60.0
64.7
69.7
75.0
80.6
86.7
93.1
100.0
107.4
115.4
124.0
57
32.6
35.7
39.0
42.5
46.2
50.0
54.1
58.3
62.9
67.6
72.7
78.1
83.9
90.0
96.6
103.6
111.1
119.2
128.0
58
34.9
38.1
41.5
45.0
48.7
52.6
56.8
61.1
65.7
70.6
75.8
81.3
87.1
93.3
100.0
107.1
114.8
123.1
132.0
59
37.2
40.5
43.9
47.5
51.3
55.3
59.5
63.9
68.6
73.5
78.8
84.4
90.3
96.7
103.4
110.7
118.5
126.9
136.0
60
39.5
42.9
46.3
50.0
53.8
57.9
62.2
66.7
71.4
76.5
81.8
87.5
93.5
100.0
106.9
114.3
122.2
130.8
140.0
61
41.9
45.2
48.8
52.5
56.4
60.5
64.9
69.4
74.3
79.4
84.8
90.6
96.8
103.3
110.3
117.9
125.9
134.6
144.0
62
44.2
47.6
51.2
55.0
59.0
63.2
67.6
72.2
77.1
82.4
87.9
93.8
100.0
106.7
113.8
121.4
129.6
138.5
148.0
63
46.5
50.0
53.7
57.5
61.5
65.8
70.3
75.0
80.0
85.3
90.9
96.9
103.2
110.0
117.2
125.0
133.3
142.3
152.0
64
48.8
52.4
56.1
60.0
64.1
68.4
73.0
77.8
82.9
88.2
93.9
100.0
106.5
113.3
120.7
128.6
137.0
146.2
156.0
65
51.2
54.8
58.5
62.5
66.7
71.1
75.7
80.6
85.7
91.2
97.0
103.1
109.7
116.7
124.1
132.1
140.7
150.0
160.0
66
53.5
57.1
61.0
65.0
69.2
73.7
78.4
83.3
88.6
94.1
100.0
106.3
112.9
120.0
127.6
135.7
144.4
153.8
164.0
67
55.8
59.5
63.4
67.5
71.8
76.3
81.1
86.1
91.4
97.1
103.0
109.4
116.1
123.3
131.0
139.3
148.1
157.7
168.0
68
58.1
61.9
65.9
70.0
74.4
78.9
83.8
88.9
94.3
100.0
106.1
112.5
119.4
126.7
134.5
142.9
151.9
161.5
172.0
69
60.5
64.3
68.3
72.5
76.9
81.6
86.5
91.7
97.1
102.9
109.1
115.6
122.6
130.0
137.9
146.4
155.6
165.4
176.0
70
62.8
66.7
70.7
75.0
79.5
84.2
89.2
94.4
100.0
105.9
112.1
118.8
125.8
133.3
141.4
150.0
159.3
169.2
180.0
71
65.1
69.0
73.2
77.5
82.1
86.8
91.9
97.2
102.9
108.8
115.2
121.9
129.0
136.7
144.8
153.6
163.0
173.1
184.0
72
67.4
71.4
75.6
80.0
84.6
89.5
94.6
100.0
105.7
111.8
118.2
125.0
132.3
140.0
148.3
157.1
166.7
176.9
188.0
73
69.8
73.8
78.0
82.5
87.2
92.1
97.3
102.8
108.6
114.7
121.2
128.1
135.5
143.3
151.7
160.7
170.4
180.8
192.0