Forms of Payment Accepted
Free Ground Shipping on orders over $50.00
Magnaflow Mufflers are the straight Wide Open performance mufflesr with smooth deep tones. First and foremost Magnaflow mufflers are developed to be a superior product line of performance mufflers. Wide Open performance Magnaflow mufflers outflow OEM chamber style mufflers by as much as 16%. This reduces engine heat and back pressure and improves exhaust scavenging from the combustion chamber. Magnaflow mufflers minimizes the power robbing effects of the OEM system to restore torque and horsepower to the engine.

From aluminized steel, to polished stainless steel, there probably are MagnaFlow mufflers or MagnaFlow cat back systems to suit your desire.
About JMF Mufflers

Pipe Diameter and Performance

Use the guide below when calculating pipe size for custom exhaust work. Keep in mind that the goal is to improve exhaust flow. In most cases, just changing the restrictive OEM muffler and replacing it with the same size straight-though, Wide Open Performance MagnaFlow muffler will do the job.

To reduce additional back pressure, the OEM exhaust tubing can be replaced with mandrel-bent tubing of the same size or one size up from the OEM. As a general rule, you can enlarge the pipe diameter of your OEM exhaust system by 1/4" to 1/2" to increase your horsepower. However, any additional increase in pipe diameter is likely to decrease your performance; specifically, low end torque.

Engine Size
Muffler Inlet/Outlet Size
Single Exhaust Dual Exhaust
150-200 CID
100 to 150
2" to 2 1/4"
200-250 CID
100 to 200
2 1/4" to 2 1/2"
2" to 2 1/4"
250-300 CID
150 to 250
2 1/2" to 3"
2" to 2 1/4"
300-350 CID
200 to 300
2 1/2" to 3"
2 1/4" to 2 1/2"
350-400 CID
250 to 550
3" to 4"
2 1/2" to 3"

© 2003 - 2018 (formerly