Calculated Exhaust Flow Rate

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	Dimension	100	200	300	400
.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

Inlet Pipe = Inlet Pipe Area (Ft 2), Dimension = Pipe Dimension, 100 = 100 Level Silencer, 200 = 200 Level Silencer, 300 = 300 Level Silencer, 400 = 400 Level Silencer

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.*