3" Single Exhaust

Pics and info of the custom catless y-pipe and single 3" exhaust setup I fabricated and installed on my daily driver (titanium) SHO.

After reading about power gains when associated with a single 3" exhaust, I set out to fabricate my own.  This setup is very "low-buck" being made entirely out of aluminumized steel rather than stainless.  However, I did not want to take the time and spend the big money on stainless if the results were not up to my standards.  So in many ways, this exhaust system is truely a "test" system.  Total expenses for this system, including the cat. converter, resonators, muff, tip, flanges, tubing and O2 sensor bungs.... a touch more than $550. 

As it turns out, this system performs quite well.  Low end torque does seem to be effected somewhat, but top end gains more than compensate.  With the stock catback and highflow y-pipe this SHO did have, the motor seemed to hit a wall at about 6500 RPM.  It continued to rev, but didnt scream to redline like the new system allows.  Obviously, it is breathing much better.

The system is composed of a 2.25" merged to 3" y-pipe. Catless, with the collector moved closer to the rear bank. A single 3" high flow Cat will bolt to the 3-bolt flange, followed by a 3"x8" stainless 3-layer flex pipe. Behind that will be two 12" (case) Dynomax bullet muffs, a 8.5" x 18" Dynomax Super Turbo tube muff.

Idle quality is a bit rumbly, but quiet.  Cruising is very quiet.  Slightly louder than stock.  During revs the noise quality is typical of the Yamaha SHO motor, a bit raspy.  High revs, the exhaust note is sweet music!

Everything was hand fabricated using pre-bent mandrel bends.

On to the photos.

The y-pipe....

The "catback"....

And the final exhaust, y-pipe to tip...