Exhaust Mod on my 3725

[Slowpoke Slim]

Well it's no secret to the regular visitors to the Branson forum that I've been less than happy with my stock exhaust particle filter. I was having constant issues, mostly in the winter time, with not being able to keep my particle filter from clogging up. Most of this was due to not running it with a load on it in winter time. Normally not an issue in summer time, as I run a 6 ft brush hog, which puts enough load (with the warm weather) to keep it clear. But just putt-putting around in winter pushing snow doesn't work the engine, it just loafs along pushing snow. It's the hydraulics and weight of the tractor that gets the work done in winter, not the engine power.

So in winter time, I estimate probably 25-30% of the run time hours on my tractor were taken up just roading my tractor up and down the back roads, trying to put a load on my engine, and get the filter hot enough to burn the particulates out of it.

Anyway...

I was finally able to locate a local exhaust shop that was willing and able to do a little custom surgery for me. I dropped it off yesterday after work, and picked it up tonight after work.

One of my primary requirements for this mod was it had to be a direct bolt in replacement, and I wanted to have the option to put everything back to OEM stock if the need arose (trade in or sell type thing-I'll never put it back just for my own use). Or, I can at least offer the OEM parts to whomever the next buyer would be, so they would have the option if they wished.

I had originally found a replacement tractor muffler locally with a 90 degree inlet pipe on it, that according to the book was for a 2 liter diesel Oliver tractor. I thought the 90 inlet would help with fitting the replacement into the tight quarters against the firewall. The shop that ended up doing the work thought that this Oliver muffler was too small in chamber size, would be loud, and likely burn through quickly due to its small size. After the shop did some measurements, I went to the store looking for a larger replacement and returned the Oliver muffler. The one I found, is a Stanley muffler, P/N: IH-4 in case anyone out there is looking to duplicate what I had done here.

I did stay and help the exhaust guy take the hood off when I dropped it off. I would say its "possible" to do it with the hood on, but not very realistic. With the hood off, there was plenty of room to get at everything easily. The guy doing the work said it was a pretty easy and straight forward job to do the mod.

Here are the obligatory pics:







The OEM flanges on the exhaust manifold, and the bottom pipe were not touched. New pipe was bent to line the inlet and outlet of the muffler up and new matching flanges were welded on. Exhaust shop even belt sanded the new flanges once welded to the pipes, to make sure they were perfectly flat for a good seal. He even painted the muffler (I hadn't asked for this, but thought it was a nice touch), which now looks like it could be a stock configuration. He also did a very good job tying back the wires from the harness. You have to really look to see them, and they shouldn't cause any issues. I fully plan on removing the entire harness, including the data logger, but I confess I plan on waiting until its much warmer out to do this (unheated garage).

Results...

On initial startup with the new exhaust, the very first thing that jumped out at me was I was really surprised with the volume of exhaust gas pressure coming out of the bottom pipe. I had nowhere near this much pressure at the outlet pipe with the OEM filter in place. This leads me to believe that my filter must surely be at least partially clogged. There is also a noticeable cloud of smoke on cold startup. Like a "traditional" diesel tractor would have. After a minute this does clear, and I couldn't notice any smoke in the exhaust. The exhaust also no longer smells like newborn puppy pharts, but smells like a traditional diesel tractor engine. No better or no worse than any "pre-tier emission" tractor in my opinion. Also, with the data logger still connected, it is currently flashing the particle filter warning light on the dash. It is my understanding that once I disconnect this data logger from the harness, that light will go out and stay out.

I noticed an immediate improvement in power and pedal response when pulling out of the exhaust shop and loading it on my trailer for the trip home. The pedals were "snappy" again. I did a little bit of snow work when I got home, and can confirm a legitimate performance gain over doing the same function just a couple of days ago.

Side observation on the filter itself, I was surprised on how heavy my filter is. Feels like it weighs at least 50 pounds. And the outlet pipe is heavily caked in thick layers of soot. I may try to see if I can find someone with one of those video camera probes that I can stick in the inlet and outlet pipes, just to see what it looks like in there. More just for my own curiosity than anything else.

 

[LouNY]

Congratulations for the successful surgery, hope she runs good for you.
Was she any louder with the muffler instead of the filter?
My 8050 puts out a quick puff of smoke when she starts also.
The only other time I have seen any smoke was following my brother in it going down the road and pulling a grade,
just a tiny bit of a haze just before he down shifted.

 

[Slowpoke Slim]

It's probably a little bit louder, but not bad. I'm not sure if I chalk that up to the muffler itself, or the exhaust is just unplugged now. Mine was very quiet with the filter on.

 

[ThreeDFlyer]

Awesome! That turned out really nice and clean! Still has a nice factory look.
I have been meaning to do this to my Branson but haven’t had time or just haven’t clogged my DPF yet. Did they make custom flanges or did they source those from somewhere? That would be the only thing holding me up right now.
I was just going to remove the DPF and make a pattern off the factory flanges.

 

[Slowpoke Slim]

These were common off the shelf flanges that the exhaust shop had on hand.

 

[ericm979]

You can buy flanges from Summit racing.

That shop did a nice job.

 

[HawkinsHollow]

Great job! Thank you for the excellent write up!

 

[Asteral]

if i were you i would take that old filter and bust out all of the filter screen material as it is made of platinum

 

[ptsg]

That's a really nice job! They could sell those as a bolt-on kit. I'm sure they would sell a lot.

Actually that looks very close to the original exhaust on the non-DPF Branson tractors. Here is a picture of one:



Please keep us updated if you notice any performance changes whenever you get more seat time.

Must feel nice to be able to idle the tractor more now and also not having to run stupidly high RPMs and burning much more fuel just to keep the DPF happy.

 

[Slowpoke Slim]

Looking forward to using the 540E setting on my PTO again for mowing this summer. I had given that up previously in an effort to keep the filter hot (by running higher engine rpms while mowing). Hopefully can save some more fuel this way, + less overall run time.

But for now, we're supposed to get some more snow Saturday, we'll see if it actually shows up or not. Maybe 6 new inches coming.

 

[Slowpoke Slim]

Oh, and I looked at my soot cooker again today. I had it backwards. The heavily sooted up pipe was the inlet to the filter, not the outlet. Kind of makes sense. I may try to take some pictures of it Sunday, depending on what the weather actually does.

 

[450]

Slowpoke, if you don’t mind, what was your total cost? I would like to have a setup like that just in case mine clogged. We really only have a Midas up here and they don’t like doing anything outside the box. It would be nice if you could just buy one.

 

[Slowpoke Slim]

I bought the muffler at a local store for $38. You can probably fine it online, Stanley muffler # IH-4.

Then it was just labor and materials at the exhaust shop. That bill came to $330, includes removing and reinstalling the hood, removing filter, sensor lines, tying back wiring harness, fabricating and welding on a mounting bracket on the new muffler that bolts to the original filter mount, fabricating the inlet and outlet pipes (needed to be mandrel bent due to tight bends/tight clearance), welding on the flanges, painting the new exhaust, and of course bolting everything in place and leak testing it afterwards.

It was worth it to me, as I can see the quality of this guy's work, both in the welds he did, and the bends in the pipe he made. Kind of hard to explain, but you can tell by looking at it once it's finished.

I'm not sure you could have one premade, without using your own tractor as a template. It's not just the bends and length of pipe, but also the angle and rotational timing of the flanges that has to be spot on, so the flanges seal properly, and the bolt holes line up.

 

[450]

Slowpoke, thanks for the info. I could do everything myself but bend the pipe.

 

[JonnyRed]

Not trying to be a smart azz here, but you could simple gut the DPF and put it back on for no cost. Granted, that would eliminate the opportunity to return it to factory stock if you were interested in having that option. I gutted mine and plugged everything back in the way it was and have no lights on the dash. Smokes visibly at startup and some under labor but nothing unusual.

Btw Slim, that exhaust guy did a **** of a job on your muffler. I would rather have that in my engine bay than a gutted DPF just for the extra room to navigate around in.

 

[450]

I would just like to keep the original one for warranty purposes.

 

[Slowpoke Slim]

Thanks Jonny, I'm not taking it like you're being "smart xxx".

I really thought about it for quite a while first. I guess I wasn't looking at it from the warranty side of things, but more along the not knowing what the future might hold kind of thing. I talked to my dealer several times about it, and he made it clear to me that removing the filter wouldn't do anything to my warranty, and he would have no problem with servicing or repairing my tractor once I did the mod. But I was more concerned with the "what if"... like what if the bozo's in Washington pass another EPA rule that says tractors can't be sold or traded without all their original emission equipment tested and working. May never happen, hopefully it doesn't. I doubt those kinds of rules would be something to worry about in this rural part of the country anyway. Maybe in the big cities, but this is "fly-over" farm country. But my crystal ball is out of charges, and who knows what changes could happen in the next 20-30 years.

What if I decide to upgrade tractors? Go with something bigger, or just different? It would be nice to have the option to hand the dealer the box with all the "stuff" in it and say, "Here, this goes with it." Then the dealer can put it all back on if they want to, or have to because of "rules" at that point. And I don't take a trade in "hit" for not having it.

The more I thought about it, the more I liked the idea of being able to put it all back *if needed*.

I'm certain I won't be putting it back on just for my own use though. That thing can sit on a shelf in my shop until the end of time as far as I'm concerned (unless trading, as above).

And I do get the same startup smoke that you describe on yours. But it's ok with me. Any "pre-Tier" tractor will do the same.

 

[ericm979]

Slowpoke, thanks for the info. I could do everything myself but bend the pipe.

You can buy exhaust pipe bends from Summit Racing (or the local auto parts store or many other sources). Flanges from the same place. It's common to make exhaust systems without a bender that way. More welds but if you make the joints smooth the exhaust does not care. I've seen entire 4 cylinder headers done this way.

When I am buying a used vehicle I value one that's stock (or can be put back to stock) higher than one that's irrevocably modded and requires expensive parts to return to stock. Especially if it's a mod that I would not have done.

 

[Slowpoke Slim]

I wanted to post an update to this thread, I hope this is ok, instead of starting a new thread, and just referencing this one again. I thought this would be simpler.

==============================

It finally dried out enough around here that I could regrade my driveway yesterday. Got started last night after work. Made the first pass with the box blade, rippers down, and cutting a full front blade. Had to put the HST in 1st and engage the front diff when I found a small tree root with the ripper blades (was pulling a full box of dirt in HST 2 at the time). I had no lack of power in HST 2, even pulling along at 1500-1600 rpms, but I did stop the tractor (it didn't stall, just started spinning the one back wheel).

Once I finished the first pass, I flipped the rippers over, set the front blade higher, to not cut, and just let the rear blade do the re-spreading of my pulled piles of dirt. I was back to doing this in HST 2 with the front diff disengaged again. And back to running at 1500-1600 rpms. Again, no lack of power at all.

Anyway, the weather was so nice, low 70's, slight breeze, partly cloudy. I had both side doors open, and the back window open while running, just enjoying the beautiful weather. Since the mod up until now, I've been running it with the side doors and back window closed, and with the fan running (usually with heat).

What I was able to notice (hear) was that my new exhaust definitely has a deeper, resonant tone to it. Especially when running at lower rpms (while pulling the full box in HST 2). Once I changed gears, and upped the rpms the deep tone got a little higher, and the resonance quieted down. I can't say it was too loud, but it was definitely noticeable. And it sounded like a much larger machine working hard. Maybe this is what it was supposed to sound like all along? I don't know, but it was pretty obvious it was breathing deeper and heavier than it ever could have done with the dpf on it (at least mine anyway).

I did make one pass with the cab closed up, and turned the cab vent fan on, and noticed a drastic reduction in perceived noise through the cab.

I did not notice any smoke coming from the exhaust, (other than the start up smoke I get every time I start it), it was running clean the whole time. Even chugging along with the full box at moderate rpm, and when I stopped it on the root. No smoke.

So, summary time. I think if you had an open station tractor, you would notice the "new" exhaust was louder and deeper when under load, especially at moderate rpm levels. But up at max-2500 rpms, it runs quieter, without as much deep resonance to the tone.

If you had a cab tractor, with the cab buttoned up and possibly the fan running, I doubt you could notice much difference at all.

Thanks.

 

[ericm979]

The sizes of the chambers in the muffler and the sizes and lengths of the tubes or openings between them affects the sound frequencies that the muffler suppresses. Unfortunately it's difficult to get that information from muffler companies.