Testing is completed and the muffler system that replaces the reverse flow mufflers used on the W-900L Kenworth and the International is now ready to be installed on your truck.  Why was this system developed?  The stock muffler that is under the bunk of W-900L and IHC trucks is very restrictive, has between 40 and 60” of backpressure, robs the engine of fuel mileage and doesn’t allow the truck to run free.  Its impossible to obtain fuel mileage with a truck that has restrictive fuel, air or exhaust flow.  The new W-900L muffler system is easy to install and you can do it in your driveway.  Just remove the 2 stainless band clamps that hold the existing muffler to the pipes, remove the 2 brackets that hold the muffler to the chassis, and slide off the old muffler.  Notice the weight of the old unit.  It holds soot.

 

Now all you have to do is clean the dirt off the Y pipe and also the pipe coming from the engine.  Apply a little grease to the ends of the pipe so the new muffler and U pipe will slide on easily, install the 2 stainless band clamps and one 6” stainless band clamp to hold the U pipe to the muffler.   Finally, install the 2 chassis brackets to hold the unit to the frame.  You are finished and now have a free flowing straight through muffler.

  The truck will run free, the exhaust temperature will be cooler and the fuel mileage will improve. 

 

This muffler is NOT as quiet as the stock unit.  It can’t be because its free flowing.  However the noise at light and moderate throttle is about the same.  Now, when your foot is into the throttle you will now know that something is happening under your hood.  Is this bad to be able to hear the engine working?  Absolutely not!  When your tired and really not paying attention to the gauges your ear will pick up the beautiful melody of your engine.

 

Have you eve noticed that when you have a cold, food doesn’t taste the same?  That’s because you can’t smell it and smelling it is part of the taste sensation.  Well that goes for driving also.  If you can’t hear your engine working how can you drive it properly?  Did you ever wonder why racecar drivers wear thin-soled shoes?  Its so they can feel the car through their feet.