Question about pulling flies

[PlaynInPeoria]

I am going to be doing the 'undo the stinkin linked brakes mod' once RandyN does it and it works out. Yes, I'm lazy that way.  (Please save your comments on the linked brakes for the other thread).  So while I am tearing the bike all apart, I might as well pull the flies rather than spending the $375 for the Guhl reflash. I am also cheap that way.

Anyway, my question is this.  Can I expect benefits similar to the Guhl reflash?  I am looking for the enhanced torque down low. I am not putting on a pipe or Power Commander (athough now that I think about it, the $375 I save on the reflash could go towards an AreaP slip on, woo hoo!).  What are the downsides of simply pulling the flies and doing NO other mods to enhance that change?  How does the ECU respond to this?  Does it keep driving the actuators but there are no actual flies there, so it thinks it's doing something?  I don't think there is feedback, i.e. it's not a closed loop system with an O2 system.

Thanks

[ljcorby]

Being you have a 2012, there may be issues with traction control and ABS with pulling the flies....I am sure others will chime in as well to confirm or deny this.

[maxtog]

Anyway, my question is this.  Can I expect benefits similar to the Guhl reflash?

(This didn't need to be a new thread)
There are four main factors with the flash:

1) Vastly improved throttle response- this is the primary purpose.
2) Tweaking of the mixture to lean it out some for better performance and mileage.
3) No interference with the traction control.
4) Faster and easier and "cleaner" install.

As mentioned several times in the Guhl and Flies threads (hint hint), removing the secondaries will achieve only #1 above.  If you were using a PC anyway, then #2 doesn't mater.  And some people don't care at all about #3 (especially since TC will still work, just not as well).  #4 is just a personal preference.  Pulling the flies has only one real advantage (without a PC or exhaust)-  it costs nothing if you are doing it all yourself.

I am not putting on a pipe or Power Commander (athough now that I think about it, the $375 I save on the reflash could go towards an AreaP slip on, woo hoo!).

That is not a "pipe", it is a muffler.  And if you are looking to save a little weight, make more noise, or just look different than stock, that is all it will accomplish.  Since you are not interested in a PC nor an exhaust replacement, then that is a factor "for" the flashing.

What are the downsides of simply pulling the flies and doing NO other mods to enhance that change?

See above response.

How does the ECU respond to this?

It doesn't.

Does it keep driving the actuators but there are no actual flies there, so it thinks it's doing something?

It sends the signals but nothing happens and it doesn't care.  It will only matter for traction control, which will work but be less effective and much more abrupt.

I don't think there is feedback, i.e. it's not a closed loop system with an O2 system.

There is no feedback and no O2 sensor.

[Snype]

Ok... really stupid question time.  I keep hearing "pulling the flies".  Been under cars most of my life and a back-yard tweaker on bikes, and have not heard this term.  It seems to refer to a form of sled race with flies instead of huskies.  Could someone please enlighten me and give me an idea of why to do this?

Snype

[maxtog]

Ok... really stupid question time.  I keep hearing "pulling the flies".  Been under cars most of my life and a back-yard tweaker on bikes, and have not heard this term.  It seems to refer to a form of sled race with flies instead of huskies.  Could someone please enlighten me and give me an idea of why to do this?

Some modern bikes that do not have an electronic throttle have secondary throttle butterflies that allows the computer to override the input from the driver and close the throttles in a variable way.  This is used both to "tame" (deaden/slow) the throttle response on powerful bikes like the C14 and ZX14 and also for traction control.  Some suspect it also factors into emissions or mileage tests.

There is a map in the ECU that variably opens and closes the secondaries depending on throttle position, RPM, and gear.  I have not heard of them being used on cars, but non-exotic cars simply can't accelerate like bikes can

The Ghul flash changes that map so they open fully almost immediately and just stay that way which greatly speeds throttle response.  (The flash also tweaks the air/fuel mix to lean it out some).

The secondary butterfly "technology" is obsolete with an electronic throttle, because in that case, the ECU can just do whatever it wants- taking the driver throttle input as just a "suggestion".

[VirginiaJim]

 

[PlaynInPeoria]

Looks like a reflash is in my future.  When I get the new tires on it, then it comes apart for the linked brake death scenario and the ECU goes off to Mr. Guhl.

[katata1100]

The secondary flies do something very, very important- they helped the bike pass noise regs.
This has been mentioned by magazines, there is even a youtube of Guhl tuning a ZX10 and he said the same thing.
In fact, on the zx10, it is even worse than the C14- the flies open around 2400rpms, then start to close again high up in the rpm range (I don't remember the exact number)!
If you are wondering if the bike is louder without the flies, I haven't noticed, maybe it is louder to people on the side of the road.
I have a '11 so I can flip back and forth between "eco" and "guhl" mode. When I am putting about town and flip to "eco", it feels gutless in the lowend, like it has a blown head gasket.