Each to his own road. I asked because how in the hell do you know if you made an improvement over stock. Because it sounds better. You do not know and never will know pulling parts before maxing out the stock parts. LOL
Carry on

 

Because a beer farts louder than stock pipes and the factory air clearer is the ugliest thing I've seen on a motorcycle in long time. Was my motivation.........

 

you have far too much experience, with bikes I mean.
all to often I read these threads and see I swapped the stock pipe right at the dealer and now it runs like ****. what pipe is the loudest. You know what I mean. Then the next newb buys a bike that runs like **** with all kinds of mods. Like to hear someone say because I have done this before and know what makes them better. Read my sig.

 

I agree that sound isn't the measure of a bike's performance, but I absolutely disagree that you can't know if you've improved performance. You can feel the difference in performance.

Not sure what you mean by "maxing out stock parts". Stock parts are EPA compliant. It's pretty much a fact that every OEM HD engine is choked up by EPA requirements. The stock parts are for performance within the EPA specifications. The EPA specifications are for emissions, and sound... They are not for best performance.

A stage I, with a good tune, gives a noticeable seat of the pants improvement. The tune is clearly the biggest part of that equation. Obviously, a bad tune can ruin anything, OEM or modified. I flashed a friend's OEM bike with a non-EPA tune, no hardware change just the tune, and he noticed the difference. It put a big smile on his face.

If you go Stage II, it is like another bike altogether...

You most certainly can feel the difference.....

 

hattitude
a tuner was my first mod, that is how I did it on the stock bike. I felt the improvement then and with each change after. so I ask, what motivates your mod. You need a base line on the bike to measure the improvement. Most just change the pipes to get it louder. Louder actually drops power.
It is a question I often ask to learn.

 

Fair enough....

While I don't like the sound of OEM pipes, exhaust sound is not what I'm after... a better sounding engine, to me, is a side affect of opening up the engine and allowing it to breathe and run better. Louder doesn't always drop power. It's understanding what your changing, how your changing it, and adjusting accordingly. The engine is basically an air pump. The more air pumped through it, the more fuel you can add, the more power it will make. These all have to be in balance... Due to EPA emissions, any OEM engine is not "flowing" to it's maximum (sound restrictions), and it's tune will be lean (emissions restrictions). That doesn't mean they can't run well (my OEM Z06 ran really well), but when it comes to Harleys, my experience is that a small change yields really good results...

My baseline is that I've yet to ride an EPA compliant OEM Harley, that wasn't improved by any of the following: a tune, Stage I, Stage II , or Stage III...

With one exception, I've ridden my bikes anywhere from 2K to 5K before "improving" the OEM engine. I've always felt immediate improvement in any bike I've modded. In the case of my '12 limited, I was going to break it in & then ride cross-country. I had the dealer go Stage II (A/C, Exhaust, Cams) at delivery. I had the benefit of the better running engine for my trip and the mods were then included in the base factory warranty. I did my research to pick an EPA compliant cam (to maintain warranty) that would suit my riding style. In that case, I didn't know how much better the bike was running until months later. I swapped bikes, during a ride with a friend, who wanted to feel my cams. I was very glad I did the upgrades before my cross country trip...

Some just mod for looks and sound. Some will be perfectly happy with an OEM performance. But it is possible to do some research and mod for a better running, better performing engine.... For me and my experience, warranty concerns would be the only reason to wait...

 

Back to the topic. To the OP I changed out my mufflers to VH eliminators and did the K&N mod on the intake side. I made those two changes while waiting on the tuner from HD. It ran ok in most ranges but when I got the tuner and installed the download for the stage 1 setup. Bike runs much better. I have heard people say they didn't use the tuner but like others mentioned for any exhaust or air cleaner mods call for the tuner in the disclaimer so to play along with the warranty police I complied and it did help.

Now when my warranty is up next year the entire exhaust is getting yanked (yes stock EPA crap sucks power and is hot) and getting it tuned on a dyno with a power vision. I dyno-ed the last three I had at my Indy and they ran flawless. Never pinged. No decel popping, more power and better throttle response. YMMV

 

Not necessarily, chosen correctly a pipe swap will give you a bit more throat sound wise and still increase performance, nothing mind blowing but it will bump up the bike a bit. Idiots running out and throwing those big *** 3" open straights on them I wholeheartedly agree with you.

What's funny is my old lady who could care less about motorcycles ribs me constantly about mine being too quiet still. Stock MoCo hardware is designed strictly to pass EPA & emission reg's not to give the bike the best performance off the showroom floor.

 

OP, sorry for taking your thread off topic.

You would do your bike a favor by using a warranty legal tune from the dealer's tuner, for your your bike with slip-ons and high flow air cleaner.

Here's why..

Factory tunes tend to be lean for emissions. Even an OEM bike can benefit from a good (non-EPA tune) tune, however that would void the warranty. That's an entirely different issue, but I offer that info just to let you know that OEM tunes are far from perfect to begin with.

An engine is just an air pump, that adds fuel, and creates power. When you open up the exhaust AND the air cleaner, the engine is pumping more air. If you leave the AFR (air fuel ratio) alone, it will then be even leaner than before. Leaner leads to good mpg (very good), but also more heat (annoying & bad for the engine) & can lead to detonation (very bad for the engine).

With an EFI bike, a portion of the AFR tables are closed loop. That means the ECM monitors the O2 in the exhaust and can adjust, on the fly, the AFR to stay within the parameters of the called for AFR. Luckily, this area is where most people spend most of their time, when operating a bike. The other portions of the map, are called open loop. These areas use the efficiency of the engine, as designed, to calculate (estimate) the proper AFR. There is no actual real time monitoring, or on the fly adjustments... If your engine mods (like what you propose) stay within the acceptable range of the OEM narrow band O2 sensors, the ECM can do a fair (it's still lean) job of keeping the bike running well and safe, in the closed loop portions of the AFR tables (rpms v load). Unfortunately, the areas that are in the open loop portion of the AFR tables, will be even more lean than the OEM tune. A lean condition that will not be adjusted for, by the ECM. Also unfortunately, these areas of the AFR tables are at the extreme running conditions of your engine (high rpm & high load) when the AFR can be most critical... Obviously, timing figures into this equation too, but I'm trying to keep it related to air flow (which is what you will be changing). I tried to keep it as simple as possible...

Bottom line:

If you change both the air filter AND exhaust, the engine will pump more air, and will be lean to very lean, in the open loop portions of the map. If you do nothing with the OEM tune, you could cause damage to your engine.

If you ride flat, level ground like a grandma... you may never get into the open loop areas and you would be OK, not good, but OK (OEM tune is still too lean, but acceptable).

If you ride a little aggressive at times, ride with weight (two-up or loaded for touring), or like to ride into elevations with hilly/mountainous terrain, I would absolutely get whatever tune the warranty allows for your modifications. It won't be optimal (cause it'll still be EPA compliant = lean) but it would be better than leaving it as is...

I hope you can use this information. Good luck with your decision...