I've watched the "how loud is your Z?" discussion with interest. Given that I've done several performance-related things to my Z, the exhaust discussions have a particular interest.

Recently, I finally purchased the 2 1/2" Sebrings, a.k.a. Labrees, later installed venturis, and then a month later pulled them off and put the stockers back on. It's my impression that Sebring/B&B style mufflers are a poor design for an NA, and should be targeted only to turbo applications. NA really do have very different requirements.

What I found would surprise most - while the exterior volume was passable, but it was the affect INSIDE the car that was untenable. They BOOM. Tremendously. especially around 1700-2500RPM, the range you use most if you commute. So if you have a headache, you don't want to be driving for more than a half hour with them. Fun for a bit, but then then wear on you.

In an attempt to capture the different volumes, I present the "lightning loudness scale":

LIGHTNING LOUDNESS SCALE
1. stock turbo
2. stock NA
3. sane turbo (HKS, Stillen)
4. sane NA
5. mustang GT
6. Sebrings turbo
7. mustang Cobra
8. Sebrings NA
9. straight piped harley
10. straight piped Ford AC Cobra
11. NASCAR
12. topfuel dragster

MODIFIERS
headers +1/2
resonated h-pipe +1/2
test pipes in place of cats +1
venturi -1

For those not familiar with the venturi option, see http://techtonicstuninginc.com/main/...roducts_id=758 Great folks, btw!