Some Exhaust Modifications

Last year after the fall bug run, you may remember, I purchased and installed a new EMPI GT exhaust for the bus.  I really like that exhaust, the look, the sound, etc.  It is just a nice exhaust, however, it doesn’t work very well for a bus!  The problem lies with aerodynamics.  Apparently, there is a large swirl that forms in the back of the bus.

This swirl seems to keep the exhaust gasses and any other junk that gets caught up behind there, in a state of swirling suspension until it finds a nice new resting place, either on the bumper, rear glass, or the paint on the entire rear of the bus.  It is very messy.  

The solution?  Exit the exhaust way off to the side of the bus, just like the VW engineers figured out many years ago.  I guess that is what happens when you install a beetle exhaust on a bus.  Good thinking on my part! (sarcasm)

Well, at a recent VW show I purchased a couple pieces of exhaust pipe so I could re-work the GT exhaust to be a side exit.  I crawled under and started making a few measurements.  It looked pretty feasible so I started cutting!

I started by simply cutting off the passenger side twin chrome tip.  I measured and cut a piece of elbow pipe to turn the exhaust parallel to the muffler and headed toward the driver side of the bus.   After making sure things were going to line up, I cut off the remaining chrome tip and ran the right hand pipe past the left hand exit from the muffler.  Next I used another portion of curved pipe to “blend” the remaining pipes into one nice exit pipe.

After the main plumbing was completed, I used a portion of curved pipe to blend the exhaust into one of the chrome tips I had previously removed.

I tacked it all together to make sure it was straight and square.  I then welded all the seams solid, cleaned the pipes with solvent and scuffed them up a bit with fine Scotchbrite in prep for paint. 

I painted my new pipes with a high temp header paint and re-assembled the little bits I had to remove to complete the welding and painting (bumper and rear apron.)

I like the sound, it sounds the same as before, just a bit quieter.  I will have to report back on the performance and how clean the back of the bus stays.  I don’t have any “longish” trips planned to test this out any more this summer.

One additional modification I think I may do is to remove the double chrome tip and replace it with  curved piece so it looks very much like the stock exhaust, only with a much nicer tone.  I think It’s down to the appearance now.