Which exhaust is right for me?
It's really a matter of personal preference.
From a performance and sound standpoint: The Alien Head™ and Penta-Carbon™ full exhaust share the same front sections. This is the part of the exhaust that you can’t see (hidden behind your fairing) that is responsible for 90% of the power gains you will enjoy by switching to either system. The part you can see, the muffler, is responsible for the look/sound/attitude of your exhaust. Both the Alien Head™ and Penta-Carbon™ have an aggressive sound, with the Penta-Carbon™ being a bit more aggressive of the two, but not obnoxious. Brock's CT Series™ exhaust are not quite as aggressive sounding and the Brock's Performance Predator™ is more of a 'traditional' road race/street sound. The Brock's Performance CT Series™ with Quietkore™ muffler is the quietest of our offerings.
Lowering ability: The Penta-Carbon, Alien Head and CT Series full exhaust systems have increased ground clearance to help the bike perform its best at the drag strip or LSR venue (lower the bike more for better aerodynamics and less chance of exhaust damage from road debris, wheelies etc…) or if you are just going for that “slammed” look.
The Predator™ exhaust still allows the bike to be lowered, but not as much as other Brock's Performance full systems. Road Race style cornering clearance is improved a bit vs. the other systems. Exception: The ZX-14R Predator™ system allows for drag-style chassis lowering.
The Penta-Carbon™ also has a provision for a hidden noise insert, vs. the external insert/suppressor required for the Alien Head.
Where the Penta-Carbon™ shines is in customization/personalization. While both the Alien Head™ and Penta-Carbon™ exhausts have provisions for color-matched logo plates, the Penta-Carbon features a multitude of carbon fiber end caps - satin/gloss as well as a host of colored end caps with BST Black Ink to be added soon.
Utmost Performance: If you desire the 100% best possible combination of performance, power, weight reduction and bends/welds that are truly artwork, Brock’s Performance CT Series full titanium exhausts are still king. That said, the Alien Head™ and Penta-Carbon™ exhaust are so close behind that the only way to notice the difference is at the track or via side-by-side comparison, as the performance difference is nothing measurable by a seat-of-the-pants ride or ass-dyno.
Weight: The Penta-Carbon™ full polished ultra-light stainless exhaust system weighs less than a comparable Alien Head™ and around 2 lbs. (.91 kg) more than a similar CT Series™ full titanium exhaust system. All 3 of these systems weigh less than our Predator™ exhaust systems, which are designed as more of a 'Track Day" system that does not allow the bike to be lowered as much. The volume of the Predators™ elbow pipe helps mid-range torque but keeps peak power within a few percent of the others. The Predators™ altered header pipe configuration (1-4/2-3 merge vs. 1-2/3-4 merge) is also designed to boost low-end power/acceleration.