Exhaust,Fuel Management, & Intake

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CharlieA

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Several questions, first what exhaust system increases HP, not just noise? What fuel management system works good with that exhaust? Does the fuel management systems effect spark control or only fuel? Is K&N the best air filters to use with the other changes? I've been hot roddin' long enough to know some parts seem to work better with others so these mods need to be done with the total package in mind. Need your experience on this.

Thanks,

Charlie

 
There is lots of speculation about what works and what doesn't but what is for sure is that it is all guess work without a good dyno and an operator with training. Its hard to beat stock without spending a lot of time and money and when you get it just right it's only right until you change altitude, humidity, gas quality or anything else. But all the modifications are great to talk about and they make your butt look faster. IMHO

 
The only exhaust system that is going to yield any increase in HP will be a full system that includes the headers. Like a Muzzy or a HoleShot. The cats are in the OEM headers, so you gotta get those out of the way for any real increases.

Every fuel management system I have seen for the FJR only deals with fuel mapping, not spark control. I don't know if I have ever seen a FI management system that messes around with spark instead of fuel. I know they are out there, but never seen one for a bike.

Seems the best fuel system managers are the PowerCommander5 with the Auto Tune, and the Motty system used by UselessPickles.

There is a lot of discussion about K&N filters, and no agreement. Some say they suck, and others swear by them. Some claim they'll lead to premature entine wear and oil clogging the throttlebody system, and some saying they wont. many of us have tried either K&N or Uni filters and gone back to OEM. There's not enough felt difference to deal with the side effects...Real or imagined.

Regardless of what you do, it is a lot of money output for a very small gain in HP. You need to search for UselessPickles threads and see the mods he did and undid while measuring gained output. The gains were very modest, and cost lots. Most of us don't think it's worth it. The gains will mostly show up at full throttle, or very high RPMs, where we spend very little time.

Either way, FJRay is right. Without a good tuner that knows what he's doing to get it all to flow right, none of it means crap.

 
I had my 06 dynoed with a PC3 and there wasn't a large increase in HP.

I only wanted better fuel management, poor throttle response with the 06.

The result was great, what the bike should have been in the first place.

My 07 still has the poor throttle / fueling problems.

Now run with a PC5 & Autotune on the 07 and dial in my own A:F ratio's.

The only good thing with a K&N air filter is the service costs.

 
I'll save you some time and money...

1) If there's exhaust that looks and sounds good to you, and it's worth the money to you for the looks and sound, then get it.

2) If you want smoother throttle control at partial throttle (e.g., initiating acceleration into a turn) and its worth about $300 and some loss of fuel mileage to you, then get a Power Commander.

3) If you want something more perfect for your bike than the freely available Power Commander maps, and its worth another $200-300 to you, then get a custom dyno tune.

4) If you really just like tweaking stuff on your own and experimenting with balance between throttle smoothness and fuel economy for exactly how you ride, and it's worth another $200 to you (and you're able/willing to learn how to use it properly, understand air/fuel ratios, etc.), then get the AutoTune module for the Power Commander.

5) If you're super geeky and not afraid to splice lots of wires on the bike, consider the Motty AFR Tuner. It's similar to the Power Commander + AutoTune, but also includes a data logger (Power Commander requires additional modules for data logging) and the ability to setup a switch to choose between two different self-tuning maps (Power Commander can use a switch to choose between two different static fuel maps, but when the AutoTune is plugged in, that switch becomes an on/off switch for the AutoTune feature). But it's not plug-and-play like the Power Commander.

6) If you choose any of #3-#5 above, you might as well do this free/simple air box mod: https://www.fjrforum.com/forum//index.php?showtopic=105719. No one has done a before/after dyno run yet, but it seems logical that it might give a bit of extra performance. Worst case scenario: buy a new air box for ~$30 and return to stock.

7) If you want a noticeable increase in overall performance, get a full suspension upgrade.

8) If you really want a significant overall gain in engine performance, then trade the FJR for a ZX14 or Hayabusa and spend extra money on making it more touring friendly. Or maybe even a C14 with the secondary butterflies removed, full Area P exhaust and Power Commander.

The setup I've settled on is slip-on exhaust (Remus Hexacone, although there's probably no significant performance difference between any of the options out there), the "cdog" air box mod, and a custom tune (via a Motty AFR Tuner, although a custom map on a Power Commander would be just as effective). I think there's some performance gains there, but the smoother throttle and the change in looks/sound are what I actually experience and enjoy every time I ride it. If I could do it all again, I would skip straight to the setup I have now, and instead of experimenting with the Holeshot header (the primary suspect for wreaking havok on my torque curve), I would put that money toward suspension instead. That's what I'm saving up for now.

The only reason I think there's performance gains is because I've improved my 1/4 mile time at the drag strip (from low 11's to high 10's). How much of that was due to me getting more practice at launching? Or differences in temperature, humidity, wind conditions? I have no idea. One of these days, I need to get my bike back on a dyno to find out for sure.

 
Just waiting for a time when I don't need $50 (price for a set of 3 dyno pulls) for something else. If the owner of the shop remembers me, I might be able to talk him down on the price a bit.

 
I'll save you some time and money...

1) If there's exhaust that looks and sounds good to you, and it's worth the money to you for the looks and sound, then get it.

2) If you want smoother throttle control at partial throttle (e.g., initiating acceleration into a turn) and its worth about $300 and some loss of fuel mileage to you, then get a Power Commander.

3) If you want something more perfect for your bike than the freely available Power Commander maps, and its worth another $200-300 to you, then get a custom dyno tune.

4) If you really just like tweaking stuff on your own and experimenting with balance between throttle smoothness and fuel economy for exactly how you ride, and it's worth another $200 to you (and you're able/willing to learn how to use it properly, understand air/fuel ratios, etc.), then get the AutoTune module for the Power Commander.

5) If you're super geeky and not afraid to splice lots of wires on the bike, consider the Motty AFR Tuner. It's similar to the Power Commander + AutoTune, but also includes a data logger (Power Commander requires additional modules for data logging) and the ability to setup a switch to choose between two different self-tuning maps (Power Commander can use a switch to choose between two different static fuel maps, but when the AutoTune is plugged in, that switch becomes an on/off switch for the AutoTune feature). But it's not plug-and-play like the Power Commander.

6) If you choose any of #3-#5 above, you might as well do this free/simple air box mod: https://www.fjrforum.com/forum//index.php?showtopic=105719. No one has done a before/after dyno run yet, but it seems logical that it might give a bit of extra performance. Worst case scenario: buy a new air box for ~$30 and return to stock.

7) If you want a noticeable increase in overall performance, get a full suspension upgrade.

8) If you really want a significant overall gain in engine performance, then trade the FJR for a ZX14 or Hayabusa and spend extra money on making it more touring friendly. Or maybe even a C14 with the secondary butterflies removed, full Area P exhaust and Power Commander.

The setup I've settled on is slip-on exhaust (Remus Hexacone, although there's probably no significant performance difference between any of the options out there), the "cdog" air box mod, and a custom tune (via a Motty AFR Tuner, although a custom map on a Power Commander would be just as effective). I think there's some performance gains there, but the smoother throttle and the change in looks/sound are what I actually experience and enjoy every time I ride it. If I could do it all again, I would skip straight to the setup I have now, and instead of experimenting with the Holeshot header (the primary suspect for wreaking havok on my torque curve), I would put that money toward suspension instead. That's what I'm saving up for now.

The only reason I think there's performance gains is because I've improved my 1/4 mile time at the drag strip (from low 11's to high 10's). How much of that was due to me getting more practice at launching? Or differences in temperature, humidity, wind conditions? I have no idea. One of these days, I need to get my bike back on a dyno to find out for sure.
I have the Hexacones w/PC3 running the Wally K. smoothness map which you converted to Gen. 2, stock air box/filter on my '08. The bike fuels great with that map, sounds and looks great with those Hexacones and has plenty of power for me. Based on dyno runs in this link: https://www.fjr-tips.org/maint/dyno/dyno.html , there would appear to be a healthy power increase too (although his are DD cans). Speaking of suspension; I had to do the fork seals so I also did the Race Tech Gold Valve kit w/.95 springs. WOW, very nice improvement in feel and control. Now the stock rear shock suddenly feels worse! So another grand more for a nice shock and the bike will have me just where it wants me (or, er.. the other way around).

 
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Based on dyno runs in this link: https://www.fjr-tips.org/maint/dyno/dyno.html , there would appear to be a healthy power increase too

Looks like about a 5-6% increase in torque across most of the RPM range. While that is a good change in performance, it's not something you'll actually notice while riding the bike (unless you race against another closely-matched bike for reference before and after, or use 1/4 mile time slips). The smoother throttle response from the custom fuel map is what you'll really notice and enjoy.

My main point is that if all you're looking for is more full-throttle power, then you probably won't be happy with what you get for the money you put into it. If you want the sound, the looks, and the smoother throttle, then you'll probably be happy with your purchases. The slight power increase is like a nice little bonus.

 
Do what I did. Go on a diet, lose a bunch of excess weight, and bingo: what a difference.
For some perspective on this, let's say you weight 200lbs. You would need to lose 46lbs to get the feeling of a 5% increase in torque on an FJR (at lower-than-freeway speeds where drag is not so significant; the effect of weight loss on acceleration diminishes rapidly with higher speeds).

It's really easy to lose the first 24lbs. Just ditch the side cases.

 
Muzzy no longer makes a full system for the FJR. I put a dent in my Muzzy 4-1 midpipe & couldnt get another midpipe. The still bike ran exactly the same anyway but I alway thought the Muzzy was too loud. So I put the stock headers back on with Vance & Hines slip ons. The bike sounds perfect to me now but I definitely feel more heat through my boots. Performance wise I'd give the nod to the 4-1 Muzzy. Anybody ever mod the cats on the stock exhaust to reduce heat?

 
Anybody ever mod the cats on the stock exhaust to reduce heat?
Yup...That was a big deal around 2008, maybe 2009. People were posting how-to pictures, getting them powdercoated and all kinds of stuff. Then it just kind of died out. I would bet if you go to Google and search "Catalytic converter removal; site:FJRForum.com" you'll find info on it.

Someone even posted a video of the bikes sound with a full muzzy and stock pipes. A Full Muzzy and Muzzy pipes (could be wrong on the brand), the stock bike, and a decatted OEM header with Muzzy pipes. If I remember, a lot of people liked the decatted header with the stock pipe sound. It's been a while though.

 
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