Class C Generator Exhaust re-routing?

[Jevad]

Hi there, I have a 30' Class C, and have my Gene exhaust pipe drag on some pavement/driveways (including my own). I would like to see if I can re-route it so it doesnt sit 5-6 inches below the frame and sidewall.


I have a Thor Four Winds 30D with the onboard ONAN Generator mounted on the front drivers side cabinet. This mounting location has the exhaust right in the middle of the wheelbase, making it the lowest point when going over a "hump". The Exhaust for the Gene drops straight down, turns parallel and routes below the frame towards front and out the side right behind the Drivers door. I've had to create a ramp just to try and drive in and out of my driveway so it doesnt drag.


- Has anyone re-routed their exhaust on their Class C for similar purposes/reasons?

- Has anyone routed their Exhaust THROUGH their coach wall (like on a boat)?

- Has anyone redirected their exhaust instead of straight down FROM the generator - through a new hole in the Generator frame so it comes out sideways?


Here is a picture or 2 of what I'm looking at.

[Bob Denman]

It looks to me as if you could take up some "slack" out of that last hanger, and raise it up a little bit...
If you could put a 45 degree angle downturn on the end of it:

[blw2]

mine is exactly the same, except I added a resonator to the forward span.

The pipe is necessarily long and passes too close to the fuel line, fuel pump, and filter for my liking.

In mine anyway, the more logical design from the genny's perspective I think would be to shorten the pipe by just coming straight out instead of going forward first....
but
that would put it more under the living room slide

going rearward and coming out the back would be good in a way, but that would be very much longer

so I don't think there's any way to go that's much better

anyway, in several years I don't think I've ever dragged mine yet....

[ducksface]

I'm looking at your running board/house connection on the rearward side of the cab.
I'd bring it through the filler panel between the cab and running board, along the house body and be done..
You'll never step on it and you'll never drag it.
One hole drilled through that filler piece, and 50 bucks at the muffler shop.
For the little money a muffler shop charges I doubt I'd do this myself.

And really consider just bringing it straight out. What are the chances of running the generator with the slide out, and whats the cost of one of the generator snorkel things if it does become a problem when the slide is out?

[Bob Denman]

MIne hangs about two and a half inches below the bodywork...
http://www.thorforums.com/forums/att...1&d=1569017475


http://www.thorforums.com/forums/att...1&d=1569017475

http://www.thorforums.com/forums/att...1&d=1569017475

[blw2]

the problems I see with bringing it straight out instead of forward...under the slide
the bottom side of the slide is not sealed, not even close, so I'd imagine it would increase the odds of leaking a bit
and
the other thing....now that I'm thinking of it isn't such a huge problem as I'd originally thought when I considered it a few years ago...is that the pipe would be under the slide so the genturi wouldn't work, if you chose to try one.... except that maybe it wouldn't be so hard to just add a straight extension out to the outside when using it

[The Gritz Carlton]

This would require custom work and a bit of welding but...shorten the distance between where it come from the bottom of the generator (manifold) and the first bend. From the pictures, this would bring the entire assembly up a couple inches and keep the existing profile. It looks like you have clearance to raise it a tad this way as long as the running board is forward of the pipe.

[Jevad]

Originally Posted by ducksface

I'm looking at your running board/house connection on the rearward side of the cab.
I'd bring it through the filler panel between the cab and running board, along the house body and be done..
You'll never step on it and you'll never drag it.
One hole drilled through that filler piece, and 50 bucks at the muffler shop.
For the little money a muffler shop charges I doubt I'd do this myself.

And really consider just bringing it straight out. What are the chances of running the generator with the slide out, and whats the cost of one of the generator snorkel things if it does become a problem when the slide is out?

Agreed, not quite liking the bring it straight out the side, 1. it would be UNDER the slide (which would undoubtedly draw fumes into the coach). 2. it doesnt really solve my problem as the exhaust drops straight down from the Gene and going straight out the side would mean the whole exhaust would drag as the midpoint of the wheelspan.

Thanks for your thoughts.

[GVP-The Boxcar Children]

I always wondered why they don't just plumb it into the main tailpipe?
GVP

[blw2]

Originally Posted by GVP-The Boxcar Children

I always wondered why they don't just plumb it into the main tailpipe?
GVP

I've considered the same thing...
but in my case it would put it in the area near and under my awning where you might be sitting while running the genny.
and probably more importantly, there could be dynamic considerations beyond any engineering capability that they're be willing to explore, regarding the pressures competing from the V-10 against the 1-banger generator.

My wish list would be to plumb it either inside the wall....or up the rear wall of the coach someplace...going up past the roof.... think a permanently installed factory genturi hidden and nicely done.

[Bob Denman]

If they plugged it in upstream from the catalytic converter: it could cause some really big problems...

[EA37TS]

Originally Posted by GVP-The Boxcar Children

I always wondered why they don't just plumb it into the main tailpipe?
GVP

Because the Onan Installation Procedures specifically says don't do it.

"9. Do not interconnect generator set and vehicle exhaust systems."

It is interesting what one learns when they take the time to read the manual and do some research. Tailpipe Installation (Section 4.1) takes up about 4 pages of the manual.

[The Gritz Carlton]

Originally Posted by dstankov

Because the Onan Installation Procedures specifically says don't do it.

"9. Do not interconnect generator set and vehicle exhaust systems."

It is interesting what one learns when they take the time to read the manual and do some research. Tailpipe Installation (Section 4.1) takes up about 4 pages of the manual.

When I had mine serviced at Cummins/Onan in Atlanta, the guy told me every single MH installation has to be approved by them before installation. Back pressure, exhaust direction relevance to windows, slides and sleeping spaces must be approved by them. Re routing is a serious thing and your plan should be run by them for review..even simply extending the pipe. Your life could depend on it.

[Bob Denman]

I guess that they take their exhaust systems more seriously than does the typical Harley-Davidson dealership...

[The Gritz Carlton]

Most important consideration...modifications void warranties.

[Bob Denman]

Originally Posted by The Gritz Carlton

Most important consideration...modifications void warranties.

So the answer to that problem is to just never make a modification that you can't put back to stock... when the whole project goes, "Boom!"

[jabrabu]

I need that exact tailpipe. Anyone know where I can get one? All of the Onan exhaust kits I see have the tailpipe just go straight out the side, not forward and then out the side like this one. Mine rusted and came loose where it connects to the gen muffler, and it dragged on the ground, so I need to replace it.

[blw2]

I'd try muffler shops. They may not have the same size pipe though...Wehn I added my resonator teh shop I took it to welded it for me but if I recall correctly they didn't have jigs and pipe that size. Still you'd probably be able to find someone to make one up....

[jabrabu]

As an update, I got a new generator tailpipe from Thor.


I tried a local Thor dealer, and their parts folks said that I had to buy a kit that cost over $500 and had various pieces that had to be welded together.


Then I tried some muffler shops and nobody could bend pipe that size. I finally found one that said that if I brought in the pipe they had a guy who could bend it.



I called Thor customer service and got put on hold forever. It said leave a message and they will call back, but they never did.
Finally, I called and just waited until someone answered. They were able to order the part, which cost around $80 with shipping.


The replacement pipe isn't mandrel bent like the original, but I installed it and it's fine.