THE SOUND

Capitalizing on the design innovations and success of our 996 and 997
range, the starting point for designing the 991turbo exhaust had been
set high. Our trademark perfect x pipe geometry, harmonically tuned
silencer geometry, Inconel 625, and our proprietary acoustic silencer
packing materials result in a system that has become famous for that
perfect sound. Zero drone, and a raised pitch raucous incendiary howl in
higher rpms and hard throttle. The design is so perfect, that you can
even run catless versions silently at cruising speeds, only unleashing
that howl when you drive the car hard.

During development there were some clear evolutionary design steps
that we could incorporate. The secondary tail pipe allowed us to
integrate an effective gas overflow system. The concept was conceived at
the fluid dynamic modelling stage, and effectively works to cut low
rpm  noise, while allowing an effective increased cross section at
higher rpms producing a more accentuated Jekyll and hyde personality,
and slightly broader torque curves.

PERFORMANCE

Final Data on exact power figures is still being collated, but
preliminary testing indicates a maximum power gain for the decat variant
in the region from 35-45whp and 55-65nm torque

Available with a variety of HJS catalysts, in either 100 cell 200 cell, hdpe perforated foil

TECHNICAL SPECIFICATIONS

De-cat cross section 70mm OD specifically chosen for a balance of peak torque and power.

Silencer section, cross section 63mm OD

Catalysts come in a variety, from 108mm OD to 127mm OD

Manifold primaries, 41mm OD, chosen specifically for faster turbo spool

MATERIALS (TURBO BACK SYSTEMS)

Available in standard 304 grade stainless steel, weight 14kg 200cell cats, 12.5 with de-cat

Inconel 625 formula one grade material, weight 8kg

Titanium G2 silencer section is also available, weight comparable to Inconel

MANIFOLDS

Standard 304 grade stainless, weight 6kg total

Inconel 625, weight, 2.9kg total

Titanium unable to endure extreme heat

ASSEMBLY TIME

Man hours

Manifolds     18 hours

Manifold Inconel   34 hours

Cat back system  14 hours

Cat back Inconel  30 hours

Tails  12 hours

Total 44 hours (1 week)

Total Inconel 76 hours (1.7 weeks)