Here is results of before the NFW exhaust was installed and then with it on.
This is with the full length design with the tailpipes.

Weather was 85 degrees adding 1,500 feet to the 4,000 feet elevation tests were done at
Notice the lower torque comes up sooner and faster now with the end to end system being 3 inch

Design testing of end of tailpipes 2,5 and 8 inch longer then in design 2.
Each additional length to bring end of tailpipes further away from underside reduced sound level in drivers are from mid 80s DBA to 78 DBA at idle but no loss to sound level at the end of tailpipes.

Final testrun of the NFW Team ZR-1 custom exhaust design with the double wall end tips which are stainless steel
Inlet is 3 inch with 4 inch outlet.

Winter test of our NFW exhaust design
Weather 36 degrees and cloudy. Windows up and radio on and off to see if internal exhaust sound was at a proper dBA level.



Part throttle to WOT


WOT



Recorded performance data during the WOT run in part from zero to 110 MPH

Team ZR-1 Corvette Racers NFW custom exhaust test at 60 degrees and windows closed.

Part throttle



WOT run

Here is idle with windows open and then closed
Measuring sound at the tailpipe tips is 94 dbA
where in drivers area sound level is only at 80 dbA with windows open and 77 dbA with windows closed



Here is stop/go city driving that includes both windows open, closed, drivers or passenger window open or closed, radio on and verbal talk
Weather 55 degrees and cloudy



Launch from a dead stop :

This is a cold start idle. Weather is only 42 degrees so normal to see water vapor until everything gets up to operating temp

70 degrees, windows closed, 4,000 feet elevation, up to 160 MPH

Again in either case you want them to be located as close to collectors as possible

Compare after 10 years of my custom NFW exhaust design on July 5th 2019
Bullet mufflers used still sounds good, has not degraded over these years

Weather 80 F Degrees, A/C off and windows closed