Foretravel, Exhaust Upgrade

A number of owners of Foretravel motor homes have been upgrading their exhaust systems.  Many have been removing the original 'swirl' drum shaped muffler and installing the straight through stye Aero 5050XL Resonator/muffler instead.
Some increase in power, cooler engine and rear bedroom areas were claimed as well as the posibility of maybe a tad better fuel milage.

I decided to do the upgrade 'now', as I have my 2001 U320 -40' Foretravel inside a building, so working conditions are relatively comfortable and stable.  A 'motivator' was.... I recently had to replace a failed exhaust while on the road with my little Ford van based Class C.  Towed to a dealership and paying over $1200. for their parts and labor was more costly than I envisioned and now being able to order parts and do the work myself on this much larger Diesel Pusher...was thought provoking and inspiring!

OK, upfront costs?  First of all, I chose the MagnaFlow brand instead of the Aero muffler because the former, was noted as being possibly a bit quieter.

MagaFlow 5" stainless steel muffler:              $155.  online, after a coupon and free shipping
Assorted parts from Freightliner local dealer:  $145. (90 deg. elbow, 1' Flex Pipe, 4 Lap Clamps, 2 std. clamps for hangers.)
Napa store, local:  2 hangers.  $10.
5" Exhaust tip, down turned, polished and 14" overall, from Thoroughbred Diesel.   $75
Titanium Heat Wrap:  Bought 2 rolls of 100' each/2" to contain heat inside piping and muffler. $165. from Summit Racing Supply.
Hi Temp paint-2 types/undercoat and top coat.     $20.
Total  $570.  (vs. the +$1200. cost for a partial replacement on the Class C.)

Note: used 10" of the flex pipe directly after Turbo down pipe, 10" of straight exhaust pipe after muffler and 10" of angle iron(for forward hanger)just after the flex pipe.

To begin with, I decided not to remove the exterior painted sections of this motor home to gain easier access to the area I'd be working on.  I got on a creeper and looked underneath and determined I'd rather take a little more time to remove the old muffler system, rather than take any chance of damaging the metalic gold paint on the exterior of my coach by removing panels.

 I was particularly concerned about the painted areas along and around "C", a removable flexible strip.

Now, to be totally fair to others who have done this job, I determined that I could get myself under and into the areas I needed to work without too much stress on my common, damaged and less flexible body!  However, being 5'8" I'm sure was a big determining factor.  Had I been closer to 6', I'd pay a paint shop to fix the paint and remove the panels to make this job easier.

I cut some lumber previously used for scaffolding on another project, into a simple ramp system, that would raise the rear of the coach 4.5".

Over a period of 3 days, I crawled under the back of the motor home and found I could actually either sit or kneel underneath and gain access to the highest bolts and nuts that would have to be removed.  This allowed me to spray them a couple of times per day with Sea Foam penetrant.....a Great Product!
I also used a small propane torch to heat the nuts first, then wait a few minutes before applying more penetrant.  This made the job of removing those nuts and bolts, doable...but not easy.  Rusted threads made using force a necessity, but with a breaker bar to gain some leverage, everything came apart as needed.

I did use a sawsall to cut the exhaust pipe away from the bottom/rear of the original muffler.  Once the tailpipe and tip were removed from the exhaust portion of the muffler and the flex pipe released from the intake side of the muffler(from Turbo), the muffler was ready to drop.  Rigging a couple of wraps of line around the muffler from it's overhead support allowed easy lowering of the really heavy barrel shaped OEM muffler.  For this, I needed a friend to help.  I stood outside lowering the 2 rope slings, while he unscrewed the final threads of the nuts holding the muffler and guided it down.

Once the old system was out, there was plenty of space under the coach to see what was needed for the new installation and plenty of room to work.

It was quickly noted, that unlike the installations of others, that I could use flex pipe, one 90 degree elbow to the new MagnaFlow Muffler, then a short straight pipe and exhaust tip. This would shorten the list of parts needed, keep the muffler up inches higher and no 45 degree elbow would be required.
Plenty of space between the intake's Air Filter and the Air Conditioning condenser was available.

 System Installed:  View from below.

View from Above.

A 'slight' twist DOWN and a 'slight' twist OUT, on the 90 degree elbow gave a perfect alignment through the new muffler and the exhaust tip to the exit hole!

 View looking forward from engine access door.  This photo is early on, with NO clamps in place.

Now...clamp installed vertically as it was in original installation and an added clamp horizontally to keep the new Exhaust Tip, perfectly centered in the body of the coach.

 After a 50 mile test drive, I felt a slight increase in power(torque) in the 1300-1700 range... Totally a seat of the pants estimate!  No increased noise at all.  Best of all?  I'm good for at least a decade of no exhaust problems!  Yay!!

Well, one last step.......now after a couple of days taking Aleve.  This entailed wrapping all exhaust from the turbo to the end of muffler with 200' of the 2" Titanium Exhaust Wrap, I purchased from Summit Racing online.

Before installing the Heat Wrap 2" tape, I nearly forgot to mention this...I sprayed the entire new exhaust system with 2000 degree High Temp exhaust spray.

 Even though some of the components are stainless steel, stainless is stainless, not rust proof.  IF kept in a wet condition, all metals including stainless will eventually fail, so painting them first and with the best High Temp paint, should add an extra layer of protection and longevity.  The paint requires heating and cooling 3x to cure, so plan for this before moving on to wrapping the system.

I started by folding some of the heat wrap back and forth every 11 inches or so,  to eventually create a band of it, 22" long.  This was used to cover the front end of the muffler, where it jumps in size from the 5" front tube, to the 7" muffler.  I taped along the ends of the fold, to hold things in place, then sewed down the middle to hold it all together for the wrapping procedure.
(Photo above was a short test piece)

The 22" long batch was then placed over the forward end of the muffler and held in place by some twisted wire at the end of the 5" pipe and just over the front edge of the 7" muffler.  This covered the interchange of 2 different sized sections and made wrapping this area simple and well insulated.

A close up of the wire, twisted together at the ends, holds the wrap firmly in place.

My buddy Joe, helped out as this certainly appeared to be a 2 person job...and it certainly was easy with the 2 of us. Note, plenty of space underneath to do the job, using the 4.5" high ramp made of 2x12" lumber.

Wrapping began up close to the Turbo itself, continued until the tail end of the muffler then back to the Turbo.  This last wrap going forward, allowed the lead edge of every wrap to be tucked under the one in front-making it less likely to get water intrusion into the layers.

The first layer, shown from Turbo on engine.

Soaking the roll of Heat Wrap first for a few minutes provided a nice soft material that was very easy to wrap and conform.

Once at the muffler it was easy to just jump up to the 7" section, as the face of it had already been well taken care of.

Job almost done.  What is left to do,  is to spray a solid coating of a special Silicone paint to seal the Heat Wrap so it will not hold water against the metal causing rust or crevice corrosion on the stainless.

This project was made relatively easy, by several online videos covering the installation of Heat Wrap and some very well documented Aero Muffler installations accomplished by owners of  Foretravel motor homes.

Any questions?  Just email me directly:       s.v.memoryrose@gmail.com 

I'll be glad to offer any info that might help you on this project.