Quiet pipes are the real deal. I had damaged my Sidepipes and bought a new set FFR Stainless Steel Sidepipes. After a spirited season of driving throughout New England my wife asked if there was something I could do to quiet the car down so she could enjoy it more. So, the search was on for an exhaust system that would give that classic deep muscle car sound without vibrating the neighbor’s windows or setting off car alarms while driving through parking lots or having my neighbors stop me to complain about the noise!
I did the research, reviewed articles, called several different manufacturers and narrowed my choice down to Boig Motorsports Quiet Pipes and FlowMaster Slimline mufflers “designed for the Cobra.”
With the help of great friends I was able to conduct an analytical sound level test on my vehicle with three different sets of sidepipes. We conducted all test under identical conditions to verify results.
Each sidepipe muffler assembly was new, installed with new gaskets and aligned with the hangers fitted.
I’m running a Ford Racing 351-W, bored to 392-C.I. @ 430-H.P. With a Holley Ultra 750 – CFM Double Pumper Carburetor, non-catalytic 4 into 4 Headers and Factory Five Stainless Steel Sidepipes.
Sidepipes tested:
1. FFR Stainless Steel Sidepipes. (Used as the standard reference.)
2. FlowMaster Slimline Sidepipes fitted to FFR flanges, pipes and turnouts.
3. Boig Motorsports Quiet pipes.
Test Conditions:
Engine full hot operational temperature, outside in an open area.
TEST FFR FlowMaster Boig Motorsports
RPMs Stainless Steel Slimline Quiet Pipes
Idle 750-800RPM 104dB. 105dB. 90dB
1,500RPM. 106dB. 106dB. 92dB
2,000RPM. 107dB. 107dB. 98dB
3,000RPM. 111dB. 114dB. 104dB
RESULTS
1. The FFR Polished Stainless Steel Sidepipes look great on the car. They created a clean sound that rolls like thunder, but they leave your ears ringing after driving a long distance on the highway and having a conversation is difficult. As they age, they get louder.
2. The FlowMaster Slimline Sidepipes when started spun heads as they barked loud and raspy. As we increased RPM’s FlowMaster Pipes got progressively louder making conversation difficult at a 45 MPH cruise and impossible at highway speeds.
3. Boig Motorsports Sidepipes is the clear winner. These Sidepipes generate a muted, classic deep pulsating muscle car sound that lets you know there is something special under the hood with no loss in performance. The Quiet Pipes allow for a conversation at wide open throttle and you can continue that conversation at highway speed. The precision welding, the fit and alignment of the Boig Motorsport Sidepipes made installation easy as well as putting a beautiful finishing touch to my build!
My son and I drove the Roadster to Florida, 1,350 miles, most that at 75MPH+. It was easy to carry on a conversations at any speed. Today the Boig Motorsports Sidepipes look and sound as good today as the day they were installed.