Calculated Exhaust Flow Rate for a Silencer With Pressure Drop of 1.0" Hg or Less
If pressure drop requirement is 1" of Hg or less and exhaust flow rate (CFM) is known, the following chart
can be used to determine silencer size without calculations. Find the lowest flow rate on the chart that is equal to or greater than the flow rate of your engine under the appropriate silencing
level.
Inlet Pipe Area (Ft 2)
Pipe Dimension
100 Level Silencer
200 Level Silencer
300 Level Silencer
400 Level Silencer
.0031
.75
41
35
29
-
.0055
1
73
63
52
-
.0085
1.25
113
98
80
-
.0123
1.5
163
142
117
-
.0218
2
288
250
206
-
.0341
2.5
450
380
325
-
.0491
3
650
565
470
-
.0668
3.5
880
770
640
-
.0873
4
1160
1000
830
790
.1363
5
1810
1580
1290
1240
.1963
6
2600
2250
1870
1770
.3491
8
4600
3900
3340
3150
.5454
10
7200
6200
5200
4950
.7854
12
10200
8800
7500
7100
1.069
14
14000
12000
10200
9700
1.438
16
18000
15500
13700
13000
1.760
18
23000
19800
16800
16000
2.180
20
28400
24300
20900
19700
2.640
22
34400
29500
25300
24000
Note: These precalculated exhaust flow rates are based on an end in end out silencer. Please refer to specific specification sheet when determining back pressure for a side inlet or
middle side inlet silencer.*
