to flie or not to flie, that is the question...

[Motornoggin]

I have an 08'. I have a K&N filter, cut 6" off the stock pipe and have removed the 'flies. I did one thing at a time starting with the filter, then the pipe, then the 'flies. Removing the flies BY FAR produced the most positive results. It no longer has the dead spot right off idle, it no longer jerks at low load/rpm, the transitions are much, much smoother, it feels stronger where it is needed and so far my economy is slightly better.

[ZG]

What year do you have, if its a 10/11 then removing the flies impacts the traction control from what I understand. Going the flash path addresses this issue.

I have an 09 Stewart.

[OregonLAN]

I removed my flies at approximately 1000 miles. With the right screwdriver, it takes ~15 minutes to remove or install them. I definitely noticed an improvement in low end torque/acceleration.  My fuel mileage also improved 1 - 2 MPG according to the display. Unfortunately, the side effect of this mod is that the throttle IS a bit more responsive (on/off). I hear you can correct this with a throttle tamer, but I've become accustom to the changes over time.

[ernie4110]

I pulled my flies the morning after I drove her home. I rode a demo bike before I bought mine and did not like the performance in the 2-5000 rpm range. Pulling the flies did add a lot of low end performance. Since then you can now reflash your ECM and have the flies open early using a map instead of mechanically removing the flies. I would do this if I started all over again. Get rid of the cannon of an exhaust an reflash the ECM. You will be happy with the outcome.

Rash

[Jeremy Mitchell]

I can't give you dyno numbers in black and white, but I can put it like this.  It is almost like the difference between a V6 and a V8 Camaro (new).  The low end grunt is there and it also pulls harder in the upper revs also.  I noticed a little more abrubtness off throttle but nothing to make me regret my initial decision to pull the flies and add a PCV. 

[madcap]

Rode my used 09 for about 500 miles before pulling them. Had no pipes, etc on before of after the change, completely stock except for the flies. Noticed an immediate improvement in low end torque and power in general - much better response. The throttle was a little touchy, but not hard to manage at all. Fuel mileage stayed consistent.

Then I added the PCV, filter, and slip on - damn, what a better way to go!

[DaveO]

 the bike runs pretty good in stock form even  with flies in ..I feel no need to modify . If i wanted something to light my hair on fire Id go buy it.
The c-14 is to big and  heavy to be a ripper anyway.
I'll save my $$ and enjoy it for what it is.

[ZG]

ZG,

Have you looked into having your ECU reflashed with a custom map rather than going the PCV route?  This would eliminate the need to pull the flies as how much and at what rpm they open can all be adjusted in the reflash (along with eliminating the 155mph speed limiter if you want).  They can even tweak the timing advance in the reflash, though with the variable cam timing that opens up a big can of worms that would require a lot of dyno time to get right.

Here's the current thread on the Guhl Reflash
http://www.zggtr.org/index.php?topic=1585.0

And here's the current thread on the Dynotronics Reflash
http://www.zggtr.org/index.php?topic=1083.0

Yes MF, I've been reading those threads as well but it seems still a little untested fully and I do worry about warranty issues...

[ZG]

I pulled my flies at 200 miles and installed the PC V and BMC filter.  The first thing I noticed was that the power was available at lower rpms which I greatly appreciated.  My PC V promptly failed and I have been riding without it for the last 1,200 miles. I took a 1,000 mile ride last weekend and averaged 44 MPG's hauling ass. I can't say whether the PC V will help MPG's but it makes sense that it will seeing Jamie takes fuel out of the map across the board. But I will take 44 MPG's averaging 80 MPH all day 

Bottom line is remove those flies.

Are you running a full system Mighty or a slip-on?

[MrFurious]

Yes MF, I've been reading those threads as well but it seems still a little untested fully and I do worry about warranty issues...

Shouldn't be any more of a warranty issue than running a PC3 or PCV, though yes...you can pull the PC unit before taking it in for warranty work.  I actually mentioned reflashing the ECU to my dealer the other day and my concern about it possibly voiding the warranty, and he said "they" (the dealership) wouldn't void the warranty for that unless it was clearly the cause of the failure (i.e. severe detonation damage due to advancing the timing to much or going way to lean on the fuel map).

[Mighty]

Are you running a full system Mighty or a slip-on?

Oops, I have a Two Brothers Carbon Fiber slip on.  Looks great, sounds even better.  Especially under full throttle   

[C14THUNDER]

08 with 6k when I I first did the filter and 2 bro exhaust...nice little change.   Next installed the PCV...Smoothed all the little spots out and a nice little bump in performance.  A week latter I took out the flies...THATS WHAT I WAS LOOKING FOR!!!  I now had the low end torque of the Goldwing 1800 and the high end HP of a sport bike.  Would do it again in a heart beat 

[Rawman]

I've never ridden one with the flies out, so I won't even guess as to how real the improvements are.  But one thing that is not in dispute is that any improvement is only in the mid-range.  It has no effect on the actual horsepower peak which is at higher rpm.  I'm 58 years old and started riding 40 years ago.  I actually enjoy shifting gears.  Point being that you can get the same performance with or without pulling them if you are just willing on using all six gears when you want more acceleration.

Wrong!!!!!  I went from 134 peak hp to 150 peak hp AND gained 12% in torque down low.  Once you uncork the engine, it feels like 1352cc's should.

Also I gained 3-5 MPG because of the improved torque.  No longer have to downshift as often or use more right wrist to go.

[ZG]

08 with 6k when I I first did the filter and 2 bro exhaust...nice little change.   Next installed the PCV...Smoothed all the little spots out and a nice little bump in performance.  A week latter I took out the flies...THATS WHAT I WAS LOOKING FOR!!!  I now had the low end torque of the Goldwing 1800 and the high end HP of a sport bike.  Would do it again in a heart beat

C14,
When you then pulled the flies a week later did you then have to remap your PCV?

[jjsC6]

Wrong!!!!!  I went from 134 peak hp to 150 peak hp AND gained 12% in torque down low.  Once you uncork the engine, it feels like 1352cc's should.

Also I gained 3-5 MPG because of the improved torque.  No longer have to downshift as often or use more right wrist to go.

Are you saying that you picked that up with just the removal of the flies - no other mods?  If so, that's the first I've heard of that.

Just looked at your sig.  Looks to me like you picked up the horsepower you are bragging about with a number of mods.

[Mighty]

Wrong!!!!!  I went from 134 peak hp to 150 peak hp AND gained 12% in torque down low.  Once you uncork the engine, it feels like 1352cc's should.

Also I gained 3-5 MPG because of the improved torque.  No longer have to downshift as often or use more right wrist to go.

Fly removal only won't increase HP.  The Fuel controller, exhaust and air filter will. The fella you pointed that comment towards  was simply commenting on flies out not making more HP.

[B.D.F.]

In my experience- removing the 'flies makes more torque (and consequently more HP) at low- to mid- range RPM ranges. It won't do much of anything for  top end power. There is a significant gain in power and 'drivability' at lower RPM though and removing the 'flies is worth doing for that reason IMO. There will also be a significant amount of intake noise after the 'flies are removed, this is not really a problem but was quite noticeable at least on my bike.

The throttle does not get any more sensitive but there is more throttle response available. In other words, a small amount of throttle makes the same difference with 'flies or without 'flies but a larger turn of the throttle is not moderated by the secondary 'flies once they are removed so more <potential> power is available. It may take a more sensitive hand on the throttle to manage it once the 'flies are removed but recklessly grabbing a big handful of throttle is always a bad idea on a bike this big anyway. If one had been a big rough with the throttle in the first place and the secondary 'flies had been modulating the power for that person, then removing them might make the bike appear more sensitive to throttle inputs.

I personally don't look at removing the 'flies as a performance mod. as much as simply removing the factory supplied 'governor'. The bike acts exactly like a 1400 cc motorcycle should once the 'flies are removed; it is not a beast or unmanageable or anything similar but again, it is a big bike with a big, relatively powerful engine.

There are some folks reporting that they are successfully running the bike without 'flies and without any type of fuel management system, such as a Power Commander. I believe the bike will tend to run lean at low RPM and large throttle openings because the F.I. system is metering fuel based on an air management system that has been removed and the system has no way to compensate. My suggestion would be to use a Power Commander or similar to remap the fuel delivery if the 'flies are removed.

Brian

So I know many of you have pulled your flies, I still have not but am currently only running a slip-on.
 
I'd like to hear some concrete facts on pro's and con's of doing this... 
 
Does it make more hp? More torque? Less? Smoother? Harsher? (sp?) Only do with full system? Do not do with stock config? MPG? Remap required? etc, etc, etc...
 
I'd like to hear both sides of the fence on this...
 
I'm currently considering going to a full system with PCV and filter, I spoke with my shop today and they recommended not pulling the flies, they said doing it wouldn't produce anymore power, but would make it run more "rough/harsh"...
 
I'm confused. 
 
Thanks in advance! Oh, and yes I already looked through all the threads with the search feature, seems to only be pro's from people that do it (kinda broad statements like "yes, do it", etc), not much from folks saying don't because... 

[ZG]

In my experience- removing the 'flies makes more torque (and consequently more HP) at low- to mid- range RPM ranges. It won't do much of anything for  top end power. There is a significant gain in power and 'drivability' at lower RPM though and removing the 'flies is worth doing for that reason IMO. There will also be a significant amount of intake noise after the 'flies are removed, this is not really a problem but was quite noticeable at least on my bike.

The throttle does not get any more sensitive but there is more throttle response available. In other words, a small amount of throttle makes the same difference with 'flies or without 'flies but a larger turn of the throttle is not moderated by the secondary 'flies once they are removed so more <potential> power is available. It may take a more sensitive hand on the throttle to manage it once the 'flies are removed but recklessly grabbing a big handful of throttle is always a bad idea on a bike this big anyway. If one had been a big rough with the throttle in the first place and the secondary 'flies had been modulating the power for that person, then removing them might make the bike appear more sensitive to throttle inputs.

I personally don't look at removing the 'flies as a performance mod. as much as simply removing the factory supplied 'governor'. The bike acts exactly like a 1400 cc motorcycle should once the 'flies are removed; it is not a beast or unmanageable or anything similar but again, it is a big bike with a big, relatively powerful engine.

There are some folks reporting that they are successfully running the bike without 'flies and without any type of fuel management system, such as a Power Commander. I believe the bike will tend to run lean at low RPM and large throttle openings because the F.I. system is metering fuel based on an air management system that has been removed and the system has no way to compensate. My suggestion would be to use a Power Commander or similar to remap the fuel delivery if the 'flies are removed.

Brian

That sounds like a very good explanation and makes sense to me, thanks Brian!

[Barry]

My bike was purchased with flys out, Full AREA P, Filter, PC-V, and Autotune, and came with a 150 rwhp dyno sheet.  It was a little notchy or "on/off" at part throttle, and a G2 Throttle Tamer fixed it right up.  10 minute install there.

I rode my buddy's bone stock C14 (we both have 08s) and I can tell you, ride BOTH, and once you do, I can't imagine wanting to stay with the stock configuration.  My buddy fully admits mine pulls in 6th as hard as his pulls in 4th.  I put 50 miles on his bike, and it felt like I was riding a 600, and the throttle response was nonexistent - no crispness at all.  The bike simply did not pull, and nothing happens down low.  I routinely shift my bike at 3K or 4K when not riding "spiritedly" and it pulls fine at that rpm...  my buddy's bike, not so much.  I had no idea, as I had only ever ridden my modded C14. 

Bottom line, get a test ride on a properly modded C14 before deciding NOT to mod your bike.  My buddy is dying to mod his now.  It's killing him to ride his stock.........

YMMV,
Barry

[jjsC6]

In my experience- removing the 'flies makes more torque (and consequently more HP) at low- to mid- range RPM ranges. It won't do much of anything for  top end power. There is a significant gain in power and 'drivability' at lower RPM though and removing the 'flies is worth doing for that reason IMO. There will also be a significant amount of intake noise after the 'flies are removed, this is not really a problem but was quite noticeable at least on my bike.

The throttle does not get any more sensitive but there is more throttle response available. In other words, a small amount of throttle makes the same difference with 'flies or without 'flies but a larger turn of the throttle is not moderated by the secondary 'flies once they are removed so more <potential> power is available. It may take a more sensitive hand on the throttle to manage it once the 'flies are removed but recklessly grabbing a big handful of throttle is always a bad idea on a bike this big anyway. If one had been a big rough with the throttle in the first place and the secondary 'flies had been modulating the power for that person, then removing them might make the bike appear more sensitive to throttle inputs.

I personally don't look at removing the 'flies as a performance mod. as much as simply removing the factory supplied 'governor'. The bike acts exactly like a 1400 cc motorcycle should once the 'flies are removed; it is not a beast or unmanageable or anything similar but again, it is a big bike with a big, relatively powerful engine.

There are some folks reporting that they are successfully running the bike without 'flies and without any type of fuel management system, such as a Power Commander. I believe the bike will tend to run lean at low RPM and large throttle openings because the F.I. system is metering fuel based on an air management system that has been removed and the system has no way to compensate. My suggestion would be to use a Power Commander or similar to remap the fuel delivery if the 'flies are removed.

Brian

Brian, your points are very good. But one comment.  Electronic fuel injections systems can compensate to some degree for changes in air flow.  The question is whether or not the change without the flies is significant enough or not.  Because the air flow with the flies out is similar to the air flow with the flies fully open, there is a chance that the system can compensate, don't you think?  I assume there is a throttle position sensor which could effect my thinking - I'm not sure how much that would limit the ability to meter in enough fuel.  Food for thought.