P500 HMF Exhaust

[trigger]

Been researching the hell out of this for the past few days and there's not a whole lot of info to be had. Only a couple of guys have done it and they didn't exactly leave us a road map to get there ourselves. This machine's been around for a while now and it appears that no one is going to make a direct slip on for it. What I've gathered is that it would be for a foreman 500, don't know what year but only the hanger locations would change? Some of these mufflers have a packing in them and need to be repacked after so many hours. Some, like the Swamp Series, don't require packing and can be taken through water or mud and not need to be opened up afterward. They even make a snorkel for it. Another thing I've gathered is that you don't need a tuner, in fact some wouldn't run right with the tuner in place. There is an O2 sensor but I believe it's before the cat and the cat has to be cut off? It would still be trail compliant with the spark arrestor screen installed. They have 3 different ones, one that is quieter than stock, one that adds like 2 dbl, and one that adds 4 dbl. All sound better than the tractor muffler that is on it now. There are claims of better mid range power, like 3rd and 4th climbing a hill.
I've already talked to my buddy that has a muffler shop and he said he'd weld it up. Just want to make sure I order the easiest to make fit and best bang for the buck. Figured I'd pick the brains of those that know way more about it than I do and hopefully get some good feedback and proper direction. Any input is appreciated. This is the one that I'm looking at...

HMF Swamp Series Blackout

 

[dls1966]

Is it an add on or a replacement I've heard that add ons constrict the engine but they do quite it down

 

[nctrailboss]

Been researching the hell out of this for the past few days and there's not a whole lot of info to be had. Only a couple of guys have done it and they didn't exactly leave us a road map to get there ourselves. This machine's been around for a while now and it appears that no one is going to make a direct slip on for it. What I've gathered is that it would be for a foreman 500, don't know what year but only the hanger locations would change? Some of these mufflers have a packing in them and need to be repacked after so many hours. Some, like the Swamp Series, don't require packing and can be taken through water or mud and not need to be opened up afterward. They even make a snorkel for it. Another thing I've gathered is that you don't need a tuner, in fact some wouldn't run right with the tuner in place. There is an O2 sensor but I believe it's before the cat and the cat has to be cut off? It would still be trail compliant with the spark arrestor screen installed. They have 3 different ones, one that is quieter than stock, one that adds like 2 dbl, and one that adds 4 dbl. All sound better than the tractor muffler that is on it now. There are claims of better mid range power, like 3rd and 4th climbing a hill.
I've already talked to my buddy that has a muffler shop and he said he'd weld it up. Just want to make sure I order the easiest to make fit and best bang for the buck. Figured I'd pick the brains of those that know way more about it than I do and hopefully get some good feedback and proper direction. Any input is appreciated. This is the one that I'm looking at...

View attachment 96936 HMF Swamp Series Blackout

My thoughts are that one for a 16 or 17 foreman would have the fitting for the O2 sensor,and the header pipe should be usable with some mods.Best I remember,on my 14 Foreman, the header pipe was tucked in closer to the cylinder as it ran towards the rear.Maybe look at Honda parts diagrams to get some idea.

 

[trigger]

Is it an add on or a replacement I've heard that add ons constrict the engine but they do quite it down

Replacement. Tried that silent rider thing and it created too much back pressure, restricted power and stunk to high heaven. If you're just slow riding out to a deer blind it works great but not for trail riding.
Trying to go in the other direction now by opening it up, creating more flow and probably making it louder. Don't mind it being louder as long as it doesn't sound like a coffee can, which some do. Better sound, better look and even a slight power gain, it would be worth it to me.

 

[Montecresto]

I knew you’d be the one to present the next mod for the P5 that’s got nothing left to be done to it.

 

[trigger]

I knew you’d be the one to present the next mod for the P5 that’s got nothing left to be done to it.

Lol, haven't done it yet.

 

[BuckCreek01]

Lol, haven't done it yet.

And so it begins. I actually think this is a great idea for better sound and power. I would worry about tuning though as Japanese products tend to run lean. As a sport bike rider, I have installed many slip-ons and full systems. Most all required mapping/tuning to gain power value.

 

[Husker1]

Lol, haven't done it yet.

Jay at Appalachian riders did the open up and gut some mod Trigger.

 

[trigger]

And so it begins. I actually think this is a great idea for better sound and power. I would worry about tuning though as Japanese products tend to run lean. As a sport bike rider, I have installed many slip-ons and full systems. Most all required mapping/tuning to gain value.

Been looking into that too, would be nice but don't think it's necessary. Went out and took a good look at it, O2 sensor will stay put and pipe would be cut down the line from that. Took a good look at where the hangers are located and just need to find one that matches close. This doesn't look that hard to do, just worried about the tune thing. This machine is bullet proof and I don't want to compromise that, trying to make it better.

 

[trigger]

Jay at Appalachian riders did the open up and gut some mod Trigger.

Yeah I saw it, not the sound I'm going for though.

 

[Bastardchild]

I knew you’d be the one to present the next mod for the P5 that’s got nothing left to be done to it.

I think @trigger secretly wants to do rear steering on his P5, but is wasting time with this muffler thread...

 

[BuckCreek01]

This machine is bullet proof and I don't want to compromise that, trying to make it better.

I would personally worry about being too lean and the effect on the engine. I have had some weird degrading power changes with just a slip-on which normally states "no tuning required".

 

[Montecresto]

Lol, haven't done it yet.

I don’t think there’s any doubts about that...

 

[Montecresto]

And so it begins. I actually think this is a great idea for better sound and power. I would worry about tuning though as Japanese products tend to run lean. As a sport bike rider, I have installed many slip-ons and full systems. Most all required mapping/tuning to gain power value.

Yeah, and California, Oregon and Washington riders are in serious violation if they chop the cat, knowing the west coast laws....

I hope trigger does it though and it does increase power, also, IMO, the P5 isn’t that loud anyway, and the new sound could be cool.

 

[trigger]

I would personally worry about being too lean and the effect on the engine. I have had some weird degrading power changes with just a slip-on which normally states "no tuning required".

From what I've been reading, if you leave the O2 sensor it will regulate on its own.

 

[BuckCreek01]

Yeah, and California, Oregon and Washington riders are in serious violation if they chop the cat, knowing the west coast laws....

I hope trigger does it though and it does increase power, also, IMO, the P5 isn’t that loud anyway, and the new sound could be cool.

I would really like my P5 to be louder. Just wish we had more available after market options for the P5. As stated above, I have years of experience with sport bikes but they have a plethora of after market offerings that have been engineered and tested.

Concerning this mod, I would definitely be cautious and check any available information on this topic. Just my thoughts and concerns.

 

[BuckCreek01]

From what I've been reading, if you leave the O2 sensor it will regulate on its own.

Sounds like you are doing the research. I am not sure if that exhaust mod will have a negative impact on your P5. Just concerned and I will check the dark side (sportbike forum) for more information.

About a year ago, I installed a Scorpion slip-on on my 2015 Yamaha FZ-09. It did not run properly after that, so I had the ECU custom flashed for the exhaust. Runs great now. One thing I do know, too lean is bad. I guess the old school spark plug color test would work?

 

[Montecresto]

Concerning this mod, I would definitely be cautious and check any available information on this topic. Just my thoughts and concerns.

Oh I hear ya. It’s not the kind of mod that I would maverick but be interested in after the bold ones (@trigger) work out the kinks and perfect it....

 

[trigger]

Oh I hear ya. It’s not the kind of mod that I would maverick but be interested in after the bold ones (@trigger) work out the kinks and perfect it....

It has to be perfect and bullet proof or I won't do it. Just gathering all the info I can get before pulling the trigger.

 

[BuckCreek01]

A good read for this topic. Once on the site, click on the tuning tab about half way down. It discusses exhaust mods, o2 sensors capabilities and fuel mixture tuning. My sportbike was popping after exhaust mod on deceleration which is a sign of running lean.

EXO Stainless Slip On – Can Am Outlander 570 / XT / XMR (2016) – Big Gun Exhaust


From the site tune section:

• I HEARD I DON’T NEED TO TUNE BECAUSE I HAVE AN O2 SENSOR WHICH SELF-ADJUSTS, RIGHT?

This is an incorrect assumption. Just because your stock exhaust system has an O2 sensor in it does not mean it is self tuning. The stock O2 sensor is an emissions compliant component that keeps the vehicle running at 14.7 AFR (which is lean) only during light engine load conditions. The O2 sensor makes the vehicle run lean during idle, low RPM and steady cruise. The O2 sensor does not function under engine load (acceleration & full throttle). By eliminating the O2 sensor, we are able to richen up the low end with our TFI Power Box and then fine tune the fueling for acceleration and full throttle now that the performance mods (exhaust) have been added. By eliminating the O2 sensor and correcting the fueling, the vehicle should run cooler, have improved low end torque and overall smoother drive-ability.