PCV vs. Guhls flash for use with full system

[Forty9rlifer]

I've more than burned up the search function of the forum and still have yet to find enough information to make an educated decision on which fuel mapping option to go with. Throughout my research I've seen a ton of dyno charts using the PCV, filter, and either an Area P or Muzzy full exhaust with results in the 150-160+ horsepower range. With the Guhls flash all I have found is some chart's with slip ons, which I think everyone agrees doesn't offer much if any performance gain. And if a few bucks more unleashes 20 to 30 horsepower then it seems like money well spent.

The Guhls flash seems like a good bang for the buck mod, but I would really like to see some tangible results from someone using a full system with their map. I don't foresee going as far as zx14 throttle body's or anything, but I'm looking at a lot of pony's being neutered that I would like to get back as cheaply and efficient as possible.

Thanks in advance, Craig

[Rembrant]

The Guhls flash seems like a good bang for the buck mod, but I would really like to see some tangible results from someone using a full system with their map.

Thanks in advance, Craig

Try reading this thread Craig:

http://forum.cog-online.org/index.php/topic,44290.0.html

I think that is what you're looking for. As always, YMMV. Hope that helps.

Cheers,
Rem

[maxtog]

With the Guhls flash all I have found is some chart's with slip ons, which I think everyone agrees doesn't offer much if any performance gain.

Peak HP gain is not the objective of the Guhl  flash.  It is to open the secondary butterflies immediately, removing the artificially induced poor power curve and slow response.  And it meets that objective perfectly.  And it makes FAR more difference than adding more peak HP (not that it has to be one or the other, though).

And if a few bucks more unleashes 20 to 30 horsepower then it seems like money well spent.

Not well spent if you don't also disable/remove or reprogram the flies.

[Rhino]

Got my Guhl reflash last year but last week was the first time I got to try it down at sea level rather than 7500' where my house is. YOWSER! Now I know what the traction control is for.

[Rembrant]

Peak HP gain is not the objective of the Guhl  flash.  It is to open the secondary butterflies immediately, removing the artificially induced poor power curve and slow response.  And it meets that objective perfectly.  And it makes FAR more difference than adding more peak HP (not that it has to be one or the other, though).

Hey Max,
The Guhl reflash doesn't open the secondary flies 'immediately', but it does open them much earlier, and much faster. With the Guhl flash, the flies hit 100% open around 3500 RPM, and a little earlier in top gear, at around 3000 RPM.

Regarding your comment about the results of Guhl's flash "making FAR more difference than adding peak horsepower", well, that's true, but only from the point of view of the guy that is not looking to maximize his bike's peak power.

It has been well documented that the Guhl ECU reflash was designed to be a bit conservative with regards to power gains. It was designed for, and has been marketed to, the average sport-touring rider that's looking for a little more 'oomph' out of his C14. If you're the kind of C14 rider than spends most of the time between 2500-3500 RPM, with the occasional blast up to 5000 RPM when passing, etc, then you will really feel the benefits of the Guhl flash. This is where it was designed to work, and it does that, quite well.

However, if you're more on the sporty side of sport-touring, and you run your C14 a little harder, such as cruising in the 4000 RPM range, with occasional runs up to 7500-8000 RPM, then you likely wouldn't benefit all that much from a Guhl flash. It just wasn't designed for that. There have been 'sportier' power hungry C14 riders that have installed a Guhl reflash and felt no difference at all.

If you're the kind of guy that wants to spend the money on, and maximize the potential of an Area-P full system, then you're probably the type of guy that won't be satisfied with a 145 RWHP and 94 ft/lbs of torque, when 165 RWHP and 105 ft/lbs of torque can be achieved. This is why, when Craig searched, he found no information on a Guhl flash with a full exhaust system....it's a rare combination. Most guys that go with a full system are looking for max power, and will also do flies-out, PCV, BMC filter, etc, etc.

9 times out of 10, you'll see just what Craig found in his searches, a Guhl flash with a slip-on exhaust. This is what the majority of C14 sport-touring riders are doing.

I don't want to get into an ECU flash vs. PC5 debate, but since they do get compared all the time, I just wanted to point out that it is not comparing apples to apples. Different people have different needs, and will benefit from the different solutions.

I will have maps for the Area-P full system that I will share with fellow C14 enthusiasts, but that will be later in 2014.....if winter EVER ends...lol.

Peace & Axle Grease,
Rem

[The Pope]

I'm one of those that have the Guhl re-flash and a full length aftermarket exhaust (ZX14 Akrapovic Evolution to be more precise) and the ZX14 throttle bodies. I had Guhl to put in a conservative map that he had for the Area P full length exhaust for now, but I'm planning on riding up to his place when the weather warms up to get the map refined because he currently (well in December 2013) doesn't have a map for a C14 with the ZX14 throttle bodies.    I'm happy with it and would go this route again.

[Rembrant]

I'm one of those that have the Guhl re-flash and a full length aftermarket exhaust (ZX14 Akrapovic Evolution to be more precise) and the ZX14 throttle bodies.

That exhaust looks fantastic by the way, and as far as the C14 goes, one of a kind and unique.

I've had Akrapovic exhausts on other Kawi's and always loved them.

Please let us know how you do after the dyno work.
I'm curious to see how the full Akra and ZX14 TB's perform together.

[maxtog]

I don't want to get into an ECU flash vs. PC5 debate, but since they do get compared all the time, I just wanted to point out that it is not comparing apples to apples.

I think you totally missed the point of what I was saying.  I will try to reword.

When it comes to performance, disabling the flies is much, much more important than doing anything else and should be the highest priority.  If you want to also do something to increase peak HP, that is fine, but doing so is mostly a waste if you don't also address the flies.

[Rembrant]

I think you totally missed the point of what I was saying.  I will try to reword.

When it comes to performance, disabling the flies is much, much more important than doing anything else and should be the highest priority.  If you want to also do something to increase peak HP, that is fine, but doing so is mostly a waste if you don't also address the flies.

I didn't think anybody would really try to increase peak power without removing the flies, would they?...(either physically removing them, or to have them opening earlier via the ECU).

In that case, I guess I did miss the point. I thought you were saying that Guhl's ECU flash made far more difference than increasing the bike's peak power, or increasing the power throughout the entire RPM range.

Don't mind me then, I'll carry on...lol.

Cheers,
Rem

[Forty9rlifer]

Thanks Rem, that link was very helpfull, 145 seems to come up a bit short of even the owner expectations of the bike in that thread. And as far as the flies go I will be removing them if I don't go with the Guhl flash, I just wanted to see some actual numbers with Guhl's maps. I think there is wide range of ability when it comes to dyno tuning, and having someone local like EDR Performance that I'm confident in their ability may have me leaning towards going with a PCV and having a custom map for it.

Being that I just got the bike a couple days ago if I see some better results out of Guhl's flashes before I start ordering "farkles" (had never seen this word till I came here) then I may change my mind. Seems like the only disadvantage is having a slightly harsher traction control intervention, and the inability to increase rev/speed limits.

Thanks for everyone's input so far,
Craig

[Rembrant]

Thanks Rem, that link was very helpfull, 145 seems to come up a bit short of even the owner expectations of the bike in that thread. And as far as the flies go I will be removing them if I don't go with the Guhl flash, I just wanted to see some actual numbers with Guhl's maps. I think there is wide range of ability when it comes to dyno tuning, and having someone local like EDR Performance that I'm confident in their ability may have me leaning towards going with a PCV and having a custom map for it.

Being that I just got the bike a couple days ago if I see some better results out of Guhl's flashes before I start ordering "farkles" (had never seen this word till I came here) then I may change my mind. Seems like the only disadvantage is having a slightly harsher traction control intervention, and the inability to increase rev/speed limits.

Thanks for everyone's input so far,
Craig

Haha...you like the word 'farkle'?...lol.
I don't use the word myself, but it was always my understanding that it was a combination of the words function and sparkle...lol. However, I believe it was started by somebody over in the Hon-duh ST1300 world, and it's actually an acronym for something...I forget now.

I thought that thread would be helpful, since that guy did exactly what you were curious about doing. Not only that, but he did it on Guhl's dyno. Anyway, you obviously know what you're doing and it sounds like you have a good local tuner that you're happy with.

I have an Area-P full system on order myself and will hopefully be installing it at the end of the month. I had an Area-P slip-on with PCIII and flies pulled on my previous (2008) C14, and I thought it was a nice improvement over stock. That bike worked really well imho.

I can't comment too much on the traction control as I haven't tested it myself without the flies. It's functionality and/or harshness in operation with the flies removed has been debated enough. My own opinion is that once you're above a certain RPM, it likely doesn't matter much if the flies are open 100% or removed all together. The Ktrc is still going to do it's job via ignition and fuel.

Have fun, and uh...happy farkling modding!!

Cheers,
Rem

[VirginiaJim]

http://www.urbandictionary.com/define.php?term=farkle

[Rembrant]

http://www.urbandictionary.com/define.php?term=farkle

Haha!....That's what I was thinkin' of:

F.A.R.K.L.E. -- Fancy Accessory Really Kool Likely Expensive

Thanks Jim!!

[VirginiaJim]

 

[maxtog]

I didn't think anybody would really try to increase peak power without removing the flies, would they?...(either physically removing them, or to have them opening earlier via the ECU).

That was what was implied by the original poster (or at least what I was inferring).  Which is why I was saying there is no point in doing anything without first fixing the horrible "fly" situation.

In that case, I guess I did miss the point. I thought you were saying that Guhl's ECU flash made far more difference than increasing the bike's peak power

It does, if one is comparing Guhl to PC without doing the flies.  But like we both said, doing the latter would be insane in the membrane

[Rembrant]

 

[maxtog]

I can't comment too much on the traction control as I haven't tested it myself without the flies. It's functionality and/or harshness in operation with the flies removed has been debated enough. My own opinion is that once you're above a certain RPM, it likely doesn't matter much if the flies are open 100% or removed all together.

I disagree [that throttle control in TC is important at high RPM].  In fact, I think it is probably MORE important at the higher RPM's to control harshness... but that is based on my understanding of the theory because I have no direct experience with flies removed.  So, like most of our discussion on that, it is just speculation.

The Ktrc is still going to do it's job via ignition and fuel.

Ignition, yep... and based on my experience with cars that had ONLY ignition control for traction control, it is far more abrupt (less smooth) than what can be done when the computer can directly control the throttle (through either drive-by-wire or in our case, with secondary butterflies).  And there are times, especially on a bike, that the added smoothness can be quite important.

Again, take it all for what it is worth- theoretical speculation without a direct comparison of this exact application.

[Rembrant]

I disagree.  In fact, I think it is probably MORE important at the higher RPM's to control harshness... but that is based on my understanding of the theory because I have no direct experience with flies removed.  So, like most of our discussion on that, it is just speculation.

Oh, don't worry...I agree that it would be better to control the harshness at higher RPM's, but until somebody tests (compares) the traction control at higher speeds and/or RPM's, we don't know how it will react.

Currently, we don't know. The only tests were done by Fred Harmon, and all he did was test the traction control with the Guhl flash at very low RPM's, when the flies were still closed anyway. He never did test the traction control when the flies were open to 100%.

He said that the traction control operated smoother with the flies in....and that's fine, but he was comparing closed flies to no flies. His comments have kinda gotten stretched over the past year or two by everybody on the internet, right down to saying that removing the flies disables the traction control, which isn't true.

I'm going to test it myself this summer, since I have control over my own flies. However, it is my own opinion that the ignition and fuel will do their job faster than the flies can close anyway, so at the higher RPM's, I don't think it makes much difference if they're open 100%, or removed all together.

Just my 2 cents worth, nothing more. I'll test it myself and report what I find, right or wrong.

[katata1100]

My 2 cents:

I have not seen 1/4 results of a Guhl bike vs a pcv/flies out bike.
I do think that peak hp is a bit misleading because how often are your riding at peak hp? If this were a track only bike, I am sure most of the time. For me, it is rarely. When a I am pulling onto the freeway with bags and case fully stuffed, or driving into a congested city after riding for 14 hours straight, I am more interested in driveability than peak hp.
My bike is Guhl'ed and has a stock exhaust (cuz I like to listen to tunes in my helmet).

[Cuda]

You can tell Guhl you want your flys to open at 1,500 rpm and he will .