WHAT IS CHAMBERED EXHAUST?
Early OEM chambered exhaust systems appeared on various GM musclecars back in the 1960's. Sidepipe-equipped Corvettes used them, and chambered exhaust was available as an option on '69 Z-28 Camaros, & '69 Chevelle SS & big block Camaros. Olds 442's also incorporated a chambered section in the tailpipes after the oval mufflers for additional sound tuning & noise reduction. Chrysler had originally planned to utilize chambered exhaust on AAR Cudas & T/A Challengers - but for whatever reason, the finished products ended-up with a very restrictive (175 cfm per muffler) side exit exhaust with oval mufflers. Basically, a chambered exhaust muffler looked like a swollen section of pipe with "dents" in it. Inside the muffler, was a louvered core or flow tube, which reduced in diameter & restricted flow because of squeezing down the size of the path - this was a negative. As exhaust passed through this section, sound waves escaped the flow path & into the outer cavity - this is where the "dents" or "crimps" performed their magic! A unique turbulence was created in the sound waves, uninhibited by any packing material (there's no fiberglass or packing to burn-out). The crimps textured or "tuned" the sound in a way unlike other more conventional mufflers or glasspacks - vehicles running chambered exhaust had a sound all their own! Glasspacks contain packing material which absorb sound, & they generally produce a smooth tone. They also very often have a smaller diameter flowpath than the entry/exit of the muffler - this affects cfm flow capabilities negatively. A smaller flowpath also produces a quieter exhaust note.
FAQ's (Frequently Asked Questions):
| Can POWERSTICKS be installed several in a row? Yes, they have minimal backpressure. The longer they are, or several installed per bank, the more sound tuning & noise reduction you will accomplish. |
| How are they constructed - what materials? Both the outer shell & internal flow tube are a heavy 16 gauge steel. The outer shell is aluminized for corrosion resistance. Other chambered exhaust has traditionally been constructed out of lighter materials - flow tubes being 18 gauge. |
| Are they available in stainless? Not at this point - this could change if demand warrants it. |
| Can they be used as primary mufflers? Absolutely! They sound best if used by themselves. |
| Can they be used as resonators? Yes, they work fine as resonators located either before or after the main muffler(s). |
| Will they burn out? No - they contain no packing material. |
| Are they available in different sizes? Yes. POWERSTICKS are available in 2", 2-1/4", 2-1/2", & 3" in/out families. Each size family is available in three different lengths. |
| Can POWERSTICKS be welded or clamped into a system? Both - they have straight bushings (stubs) which OD pipes slip inside of. |
| How do they fit into my existing system? This is what there are exhaust shops for. There will usually be some degree of fabricating involved (pipe bending, cutting & welding, etc.) - this is why you will need an exhaust pro. A good exhaust technician can custom-bend an entire system for your vehicle & incorporate POWERSTICKS as your mufflers. Chambered exhaust is not just for GM vehicles! |
| Is this something I can use on a late-model vehicle that has catalytic converters? You bet! Chambered exhaust will really wake-up the exhaust note on any late-model V-8. Some OBD1 & OBD2 vehicles even run multiple converters on each bank which can really rob some sweet engine exhaust sound, as well as produce unwanted exhaust backpressure. *Be sure not to modify the exhaust upstream of O2 sensors or converters - that is illegal. |
| POWERSTICKS are "improved" vs.other chambered designs - how so? First of all, they maintain a true flowpath diameter - they flow more cfm. The entry of mufflers are sized ID, exhaust pipe is sized OD - this is why muffler entries/exits always fit over the pipe & then clamp. A 2-1/2" POWERSTICK is 2-1/2" ID at the entry/exit, while the flowpath is 2-1/2" OD - so it does neck down slightly. An old Thrush Turbo Tube that was sized 2-1/2" had a 1-7/8" ID flowpath. POWERSTICKS are fully constructed out of heavy 16-gauge materials - including the flow tube. POWERSTICKS do not "backrap", "cackle", or "pop" like other chambered exhaust - even on deceleration. |
| What do they sound like on a V-10, or 6 or 4 cylinder motor? So far great results on mid-90's Toyota Celica Turbo cars with custom 3" exhaust. You'll have to be the judge on these. |
| Are these emissions legal? Mufflers have nothing to do with controlling vehicle emissions, & they are not supposed to or required to. They purely control sound. |
| Are POWERSTICKS street legal? Is a high-flow air filter? Depending on what they are installed on, & how, they may very well exceed "acceptable" sound levels in your area. A "legal" sound level is in most cases determined by the law enforcement officer while he has you pulled over, & "too loud" is generally purely subjective. When was the last time you heard of someone riding a Harley getting a ticket for excessive noise? You determine what is too loud - we'll just make the mufflers! |
| What can I do if one POWERSTICK is too loud? You could either add a second one, use a longer one, or add a short glasspack to act as a resonator to soften the sound. *We may start carrying short glasspacks for resonators if there is a demand for them. |
Cobra Kit Car with a 498 Shelby aluminum block 427.
Courtesy: Kinetic Racing Engines
| HP Cobra Kit Car - Kinetic Racing Dyno | ||||
| RPM | Open Headers | Stock | POWERSTICK 3" | vs. Stock |
|---|---|---|---|---|
| 3500 | 349.9 | 307.9 | 338.1 | +30.2 HP |
| 3750 | 390.4 | 323.1 | 359.0 | +35.9 HP |
| 4000 | 425.8 | 350.3 | 398.7 | +48.4 HP |
| 4250 | 465.2 | 387.4 | 444.7 | +57.3 HP |
| 4500 | 499.4 | 402.4 | 482.2 | +79.8 HP |
| 4750 | 517.0 | 409.8 | 503.4 | +93.6 HP |
| 5000 | 531.3 | 424.0 | 519.1 | +95.1 HP |
| 5250 | 547.4 | 433.5 | 533.9 | +100.4 HP |
| 5500 | 557.1 | 447.2 | 549.8 | +102.6 HP |
| 5750 | 555.2 | 451.2 | 546.0 | +94.8 HP |
| 6000 | 562.4 | 459.1 | 545.7 | +86.6 HP |
| AVG: | 450 | 366.3 | 435 | +68.7 HP |
| TORQUE Cobra Kit Car | ||||
| RPM | Open Headers | Stock | POWERSTICK 3" | vs. Stock |
| 3500 | 525.1 | 462.0 | 507.3 | +45.3 lb-ft |
| 3750 | 546.7 | 452.5 | 502.8 | +50.3 lb-ft |
| 4000 | 559.1 | 459.9 | 523.5 | +63.6 lb-ft |
| 4250 | 574.9 | 478.7 | 549.5 | +70.8 lb-ft |
| 4500 | 582.8 | 469.7 | 562.8 | +93.1 lb-ft |
| 4750 | 571.6 | 453.1 | 556.6 | +103.5 lb-ft |
| 5000 | 558.1 | 445.4 | 545.3 | +99.9 lb-ft |
| 5250 | 547.6 | 433.7 | 534.1 | +100.4 lb-ft |
| 5500 | 532.0 | 427.0 | 525.0 | +98.0 lb-ft |
| 5750 | 507.1 | 412.1 | 498.7 | +86.6 lb-ft |
| 6000 | 492.3 | 401.9 | 477.7 | +75.8 lb-ft |
| AVG: | 499.8 | 408 | 482.3 | +74.3 lb-ft |