Guys I have done some searching on this subject, and it is about as clear as mud to me which is the better option for me.

I would like to improve bottom end response with the least amount of impact on MPG's and driveability.

I see the Dynotronics can reflash the ECU to accomplish this at about $400.00, or the flies can be removed and a PCV added.

Given my goals, is there a better of the two options? Has anyone done both that can provide a comparison?

Thank you for your help and support. 

Guhl motors can also reflash. This wasn't available when I got my '08. It may be a better option if you have a newer bike with traction control.
http://www.guhlmotors.com/

Flies and PCV.  I'd think the easiest way to void a warranty on a bike that is completely computer controlled is to hack it's brain.  The Flies+PCV can be put back to stock in about ten minutes.

IMO the biggest advantage of the PCV over the Dynotronics or Guhl reflash is the fact that you can change tunes/maps to suit your taste.  Another thing is the fact that you can add to the system for more adjustments.  I added an AutoTune to get the best of both worlds.  The best I have done on mine so far is 41 mpg, but I have only been running it for a month or so. There are several members that have reported going from 38-39 mpg to 43-45 mpg.

Flies and PCV.  I'd think the easiest way to void a warranty on a bike that is completely computer controlled is to hack it's brain.  The Flies+PCV can be put back to stock in about ten minutes.

Guhl will restore your factory settings upon request. At least that was my understanding.

My .02, for me about the only reason why I would do the reflash would be to extend the RPMs.  I have the autotune and PCV as well which is married up to an AreaP full system.  If I had done a reflash I would have had to send the ECU back for another reflash since I just got done doing the ZX14 TB swap.  I like knowing I can change things up without waiting on shipping and actual reflash.  If they ever comeout with a way to reflash at home?  I would be on it, if for nothing else to get the revs.

Unless the reflash is done on a dyno I think it is a waste of money.  You send it out, they put in some arbitrary values they have come up with who knows where. 

With a PCV, you can either use maps that various people have used and found to work (not really my idea of how to do it either as you are trusting folks you don't know), or you have it dyno tuned by a shop in your area (they are all over the place), or you buy an autotune as suggested above.  To me it's a no-brainer unless you happen to live where you can take the bike in for the ECU to be done on a dyno while you watch.

Guhl has used a dyno.  Also, Fred H worked closely with them on the current maps using an Autotune on his bike.

Flies and PCV.  I'd think the easiest way to void a warranty on a bike that is completely computer controlled is to hack it's brain.  The Flies+PCV can be put back to stock in about ten minutes.

I thought that I'd read on here that it wasn't quite that easy to reinstall the flies. Plus, if you have traction control, isn't it pretty much disabled by pulling the flies?

I've done neither the reflash nor the flies/PCV ... ... so far.

My .02, for me about the only reason why I would do the reflash would be to extend the RPMs.  I have the autotune and PCV as well which is married up to an AreaP full system.  If I had done a reflash I would have had to send the ECU back for another reflash since I just got done doing the ZX14 TB swap.  I like knowing I can change things up without waiting on shipping and actual reflash.  If they ever comeout with a way to reflash at home?  I would be on it, if for nothing else to get the revs.

Seems it was posted awhile back that this was in the works, but I've heard nothing in several months.

My 2 cent's. Flash was less complicated than pulling the flies and adding a PCV or autotune. I had x to spend, with y time and the flash was best bang for buck considering everything.

May be different for someone with garage full of tools and time.

Guhl has used a dyno.  Also, Fred H worked closely with them on the current maps using an Autotune on his bike.

I remember that, but it still becomes somewhat of a "canned" program and does not take into account any other mods on the bike.  If I recall, there were never any dyno runs done on the bikes with ECU flashes, were there?

The files would be no big deal to put back in.  Possibly even easier than removal since there would be no fighting the threadlocker.  I went with the PCV, Fuel Moto files removed map, but no auto tune (YET).  I Amy do the autotune sometime as it sounds fun, but it would be for fun.  I'v epicked up power where I wanted it (low end) and am not so worried about what the bike does at 10-11k. 

I thought that I'd read on here that it wasn't quite that easy to reinstall the flies. Plus, if you have traction control, isn't it pretty much disabled by pulling the flies?

I've done neither the reflash nor the flies/PCV ... ... so far.

Mines a 2010.  The traction control works fine with no flies. 

Mines a 2010.  The traction control works fine with no flies.

Guess I need to do a little research. I thought the traction control cut power to the rear tire by closing the flies. I must have misunderstood.

Guess I need to do a little research. I thought the traction control cut power to the rear tire by closing the flies. I must have misunderstood.

My thinking is that the TC cuts the fuel to remove power from the rear tire, then closes the flies so that when the power comes back on it will be a smoother transition back to full power.  Kawasaki has been clear that the flies are involved in the process but I've never seen anybody with a fly-less 2010+ complain about their TC not working properly so I'm guessing the flies play a pretty subtle role.

Wally, I believe that is part of it.

Is a TRE (Timing Retard Eliminator) another low cost alternative? It tells the ECU the bike is in 6th. gear and this allows the flys to open sooner. It eliminates the timing retard built into lower gears to tame response..

I remember that, but it still becomes somewhat of a "canned" program and does not take into account any other mods on the bike.  If I recall, there were never any dyno runs done on the bikes with ECU flashes, were there?

I can only speak for how Guhl Motors does their work.  Attached is the final dyno run on my bike after working with Don for close to two months in getting it dialed in. 

I can only speak for how Guhl Motors does their work.  Attached is the final dyno run on my bike after working with Don for close to two months in getting it dialed in.

Here's another chart which shows percent improvement in torque and HP over stock.  As you will see, the gains in these numbers are pretty impressive in the under 7K RPM range.  Keep in mind that this is on an otherwise stock 2010 bike. 

Don has worked up maps for several aftermarket exhaust systems.  Give him a call and talk about your mods and what he can (and can't) do.  I believe you will find Guhl Motors to be complete professionals from start to finish.  If you are anywhere within riding range, I know he will work with you on his dyno for whatever mods you have installed.