Custom Designed Exhaust System


Well-known user
It has been ten years since I designed the full custom exhaust system for my 1999 Rebel C5, custom (372 CI) 6.1 liter, stroked LS1
This was with long tube headers, no CATS, 3 inch exhaust from collectors of headers to tailpipes, all 3 inch

so was a good time to look at how the system has held up including the exhaust sound after 10 years of hard use on street or on race tracks.

Recording below as of today
is at startup cold idle, weather 50 deg, raining, humid, C5 in garage with ass end close to open door area
Sound level in Dba bit higher than 10 years ago, measured about 100 Dba but will be a bit lower in hotter weather
Hear recording by clicking here and let me know what you think what you think

Will add more live testruns when weather is better, looks like same crap daily over next week :-(
Read lots of my testing 10 years ago with test results, video, audio, etc :

Team ZR-1 X-Pipe project

To do this 10 years of use test I made a rig up and a audio system so 2 recording MICs for more of a stereo effect

Images below of exhaust system is showing when at race track trim, where all testing now is street trim where tailpipes
are added to exist just past rear of C5



When I installed the 570 hp/606 ft/lb 489 in my C3 it initially ran with the Hedman 1 7/8" headers and twin 2 1/2" system - earning the ticket below (albeit on a slippery concrete strip) - a later upgrade to 2 1/8" Super Comps headers and a twin stainless 3" system with 'X' pipe seemed to open up so much additional power over 4000 rpm.
Unfortunately I haven't had an opportunity to take it on the strip and compare. The 'seat of the pants ' effect was significant. Exhaust sound changed - not so much at lower rpm - higher revs a more significant change in sound - seeming to double-up on the exhaust pulses and making it sound like its revving far higher.



Well-known user
If a good X-pipe design and mounted correctly will pull out exhaust from cylinders so next firing of a piston
has a better AFR charge and enhance mid range torque

Finally got a day with no rain so did a testrun audio recording,
may need to adjust your speaker volume.
PIcks up road and wind noise so have to come up with a better recording process

In WAV audio format

WAV audio format

MP3 format

MP3 Format