| Hey all - as a bit of a PSA for the archives, etc. Thought I would post my experiences with my Z, in trying to quiet it down a bit. Car: 90 TT lots of mods. Exhaust: SP500's, SZ downpipes: When I first got the car, I had a Z1 midpipes, an HKS H-Pipe, and the SZ Dual Labree. The car had an awful resonance from 2K-2.7K. I replaced the SZ Duals with the "updated" perforated core muffler version (vs spiral core mufflers) that they started selling in January. This quieted the car significantly under WOT, but the resonance remained fairly insistent from 2-2.5K. Next, I installed SZ's midpipes, with a flex section, and resonators at the back. This reduced the resonance somewhat, but the car was still very uncomfortable to drive around town. Quality was superlative. the Z1 midpipes were 2.25" diameter, crush bent, and generally "OK". Worth the price, I suppose. I tried putting 50# worth of B-Quiet (aka Brown Bread) in the trunk and rear firewall area, and that helped slightly as well, but still no dice. Finally, I put an extra layer of sound deadening all around the trunk area, and in front of the wheel wells. The car as a whole is now much quieter, but the resonance remained very uncomfortable - driving for more than 15 minutes with the windows up left me with my ears throbbing. SO, I recently replaced the SZ duals (*sob*) with a Stillen muffler, and the Stillen X, which has no resonator. (the HKS H-pipe also was resonated). The result is near zero resonance now - just a hint at about 2.2K and large throttle angle (i.e. lugging it around in 4th or 5th gear). So, the resonance is gone. Qualitatively, every single part from Specialty-Z is superlative in quality. I was ashamed to put the midpipes and mufflers on the car, becuase they were so absolutely beautiful. The stainless split downpipes are gorgeous. I've had headers from my Corvette, carbon-fiber racing parts and custom stainless headers on the Radical, and I don't think I've ever seen such nice parts as the guys from SZ are offering. If I weren't such a festering wuss about my car's volume, I'd have SZ exhaust parts from turbo to tip. Sound-wise, the SZ duals were *great*. A lovely idle growl, fantastic sound at wide-open. But for that 2-2.5K resonance, they were fan-f******-tastic. Conversely, regarding the Stillens, I have to say, the parts are pretty junky. The welds are hideous, the construction is generally pretty rinky-dink, and the tips don't look as nice as the SZ's. It's basically one step above stock in appearance and "quality". They do appear to be strong, so I don't have any concerns about longevity, but they are simply appalling compared to the beauty of the parts from Specialty-Z. Sound-wise, it is acceptable. A reasonable growl at idle, and enough grunt at full throttle, with one exception: WOT above 15psi and around 5K RPM (on my particular car), the exhaust note changes from the normal V6 growl to this awful blowing-too-hard-through-a-small-straw that is 100% unsatisfying. No power dropoff seems to accompany it, but it's a far cry from the roar the SZ mufflers had. But, in the end, for me, it's a necessary evil to be able to tolerate this car driving it 60 miles every day, and to be able to hear my (meager) stereo at less than full honk. FWIW. Hope this helps somebody in the future... -Jake
My Radical (SCCA DSR) | My 300ZX TT | jakelatham.com |
