| Harley-Davidson Performance Guide EVO
Exhaust
System Testing |
Maximum Horsepower Output
Very few riders will question
the fact that a good exhaust system is required for making more
horsepower. Trying to determine which is the right pipe for your bike can
be a daunting task. Motorcycle Performance Guide is going to offer its
experience in exhaust pipe testing and offer some suggestions for the
average rider.
So which is best?
Below is the summary of testing done by one of the
industry magazines. The test bike was an 80CID EVO style engine at 9.5:1
compression using a Crane Fireball 310 camshaft and a Mikuni HSR-42
carburetor. The engine is a very conventional "Stage 2" engine.
For various exhaust systems, chart shows horsepower from 2000 to 5500
RPMs, average horsepower, maximum horsepower, street power ranking and
maximum horsepower ranking.
|
|
Kerker 2-1 |
Super Trapp 2-1 20
disk |
29" Drag Pipe |
29" Drag Pipe
w/screw |
West Coast Chopper
Hell Bend |
RB Racing 2-1 |
V&H Straight
Shots |
Samson Long Shots |
White Bros Porker
Dual |
Cycle Shack
2" Duals |
Custom Chrome 2"
drags |
D&D Power Drag |
Python 3 |
Jammer 2-1 |
Chopper Guys 2-1 |
Hypex 2-1 |
Bartels 2-2 |
Hooker 2-1 |
HD 2-1 |
|
2000 |
20.5 |
20.6 |
20.3 |
20.9 |
19.8 |
25.5 |
20.7 |
24.2 |
23.9 |
20.0 |
25.9 |
20.6 |
23.3 |
22.0 |
23.1 |
21.7 |
20.1 |
21.7 |
16.5 |
|
2500 |
28.1 |
32.2 |
34.2 |
33.6 |
31.9 |
25.1 |
34.8 |
23.3 |
28.0 |
34.5 |
31.1 |
33.3 |
34.1 |
32.3 |
28.3 |
29.0 |
34.6 |
32.1 |
18.0 |
|
3000 |
31.9 |
38.7 |
42.1 |
42.9 |
39.1 |
35.4 |
37.2 |
36.7 |
33.7 |
41.1 |
26.3 |
37.0 |
37.3 |
40.5 |
43.6 |
41.8 |
41.1 |
37.5 |
23.1 |
|
3500 |
50.2 |
52.2 |
45.6 |
49.1 |
46.5 |
50.1 |
48.1 |
52.2 |
50.1 |
49.4 |
31.2 |
49.4 |
45.9 |
53.7 |
54.5 |
53.1 |
47.3 |
50.2 |
36.6 |
|
4000 |
62.1 |
61.7 |
50.7 |
55.6 |
55.9 |
62.0 |
61.6 |
61.7 |
61.5 |
60.1 |
57.0 |
61.7 |
59.6 |
62.0 |
59.1 |
61.3 |
59.2 |
63.0 |
41.3 |
|
4500 |
70.1 |
68.6 |
61.1 |
65.0 |
64.2 |
69.4 |
69.7 |
68.6 |
68.0 |
68.3 |
68.9 |
69.1 |
70.4 |
66.2 |
62.1 |
69.1 |
70.0 |
70.9 |
39.9 |
|
5000 |
75.1 |
75.2 |
73.3 |
74.7 |
71.3 |
74.7 |
75.5 |
73.1 |
71.9 |
73.5 |
77.6 |
74.2 |
76.3 |
66.9 |
66.2 |
74.6 |
76.1 |
75.8 |
30.1 |
|
5500 |
77.0 |
78.7 |
79.7 |
79.3 |
77.0 |
77.1 |
78.5 |
75.3 |
74.1 |
76.6 |
79.0 |
75.0 |
79.4 |
65.9 |
72.2 |
77.8 |
80.1 |
79.0 |
35.7 |
|
Average Horsepower |
51.9 |
53.5 |
50.9 |
52.6 |
50.7 |
52.4 |
53.3 |
51.9 |
51.4 |
52.9 |
49.6 |
52.5 |
53.3 |
51.2 |
51.1 |
53.6 |
53.6 |
53.8 |
30.2 |
|
Maximum Horsepower |
77.0 |
78.7 |
79.7 |
79.3 |
77.0 |
77.1 |
78.5 |
75.3 |
74.1 |
76.6 |
79.0 |
75.0 |
79.4 |
66.9 |
72.2 |
77.8 |
80.1 |
79.0 |
41.3 |
|
Street Power Ranking |
96% |
99% |
95% |
98% |
94% |
97% |
99% |
96% |
96% |
98% |
92% |
98% |
99% |
95% |
95% |
100% |
100% |
100% |
56% |
|
Horsepower Ranking |
96% |
98% |
100% |
99% |
96% |
96% |
98% |
94% |
93% |
96% |
99% |
94% |
99% |
84% |
90% |
97% |
100% |
99% |
52% |
After looking at this table, you may think that the most
horsepower is the best pipe. That isn't always the case. Maximum HP only
occurs at one point in the power curve. When you are riding on the street,
your engine is operating over a wide variety of RPMs. The best average
horsepower or the Street Power Ranking is going to provide you with the
most usable power.
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