How to Build a Stainless Exhaust with Vibrant Performance

How to Build a Stainless Exhaust with Vibrant Performance
By Mike Kojima

A lot of times a pre made exhaust just wont do it.  You might have a car that no one makes an exhaust for.  You might want to make a big diameter turbo exhaust for a car that never came turbocharged.  You might want to make a special exhaust for your own special requirements.  

The Protech mid pipe has this cool ball and socket that is compatable with the factory part on the 20V exhaust manifold.  The stock 20V exhaust maniold outpowers most headers on the market but needs a 3" exhaust.  The Protech part is 3" mandrel bent steel that is cermaic coated.

In our case we wanted to build an exhaust for a 92 Sentra SE-R.  There really isn’t much aftermarket interest in this car any more and when there were commercially available exhausts, they were small diameter units for mild bolt on engines.  We were bolting in a pretty healthy NA SR20VE engine into the car and a 2” or 2.25” system was not going to cut it.

We used a Vibrant Streetpower muffler as our main muffler.  It features all stainless steel constructionon and is ceramic coated black for stealth.  It is a high quality unit and has about zero backpressure.

For a healthy NA motor with a lot of overlap, you need a big really low back pressure system.  We wanted a 3” system and there wasn’t anything like this on the market.  In addition. we wanted our big exhaust with super low backpressure to be both reasonably quiet and to not make excessive emissions.  It’s a challenge to get an NA motor quiet with a large exhaust because there is no turbo to act as an effective silencer on its own but we were going to give it a shot.

The Streetpower muffler has a straight through perforated core making it an absorption type muffler.  No baffles or louvers to cause turbulence and back pressure here.  The body is larger than typical round straight through mufflers for good silencing  and is packed with stainless wool and fiberglass.  It is very hard to make a large diameter. low backpressure exhaust quiet on an NA car because a turbo really makes the exhaust note quieter before the exhaust gas hits the exhaust system.

We were also running an OEM SR20VE 20V exhaust manifold in lieu of a header on our engine.  The 20V manifold is known to make more power than most commercially available SR20 headers on the market, even on highly modified motors.   It has large primaries and merged collectors in a long runner tri-y design where cylinders 1-4 are paired with 2-3 at the collector.  The collector has a 3” in diameter exit, unusually large and it’s going to take a 3” exhaust to extract the maximum power from this manifold.

Vibrant's race catalytic converter uses a low backpressure 100 cell metal core.  The metal core is thinner than ceramic cores and has less frontal area for lower backpressure.  The cat's stainless steel case is also profiled for good flow.  We used this cat so we would not be a gross emitter.  We also fabricated a test pipe for tuning and track use.  This cat is not street legal on late model OBDII cars and may not be legal in all states.