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KRT
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Discussion Starter #1
Hi, new to the site, my first "new discussion starter"...
Re: Stock vs. aftermarket ECU/controllers;
Kitaco Hi-comp piston, Hi-lift valve kit:

I already have an "SP Tadao" loop megaphone pipe (with end baffle) - but that's the only engine mod.
The engine has been running fine. No glitches at all.
I bought the Kitaco piston/cam kit, but wanted to hear something about ECU/controllers with this mod.

Kitaco says that you CAN use the stock ECU (and airbox), IF you use their own "Extreme R" pipe. They say if you use any other pipe, you'll need a "fuel adjustment". (This is translated from Japanese, I think, so I'm not sure of the accuracy or completeness - a difficulty I have, living here in Japan...)

Just looking at the Kitaco pipe, there's no obvious differences between it and my SP Tadao (or many others on the market) - maybe a bit shorter from port to muffler, maybe the muffler section has a bit more volume.
I'd be tempted to just install the kit and see what happens - but this bike is my only transportation right now.

If I have to pay for another controller, I'm looking at the "Enigma" - because everything else is out of my price range. I can get the Enigma (a "piggyback") for $300 or less, here.

The good folks at "Steady Garage" in Irwindale, CA, have recommended the "aRacer" controller with "wideband O2" sensor - and from what I read it's probably the best suggestion. But it's WAY out of my price range, and I don't need "absolute performance". (This is why I think the hi-comp piston/hi-lift cam will be enough for my needs - and I'm already beating all the locals in the little drag races stoplight to stoplight... ;-)

So I'm anxious to hear about you all's experiences, and opinions!
Thanks!
(Also, I don't look at the site everyday - so please accept my apologies if I don't seem to be responding...)
 

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Discussion Starter #2
...plus...
(thanks Kaw'ee, for showing how to upload photos...!)
Here's the Kitaco piston/cam kit - still a 125, don't think I need/want a "big bore"...
And, the Kitaco exhaust - will later try to post photos of my SP Tadao pipe...

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So just know that you will need some type of fuel controller before you install that kit. Adding the pipe reduced back pressure some, but the stock airbox won't allow too much additional airflow, so the stock ECU was able to adjust. But if you also raise the compression & increase the valve duration with the kit, the ECU won't be able to add enough additional fuel. I have used that Kitaco kit in the past and it provides a usable increase of power while being easy to install but it needs to run much richer than stock. The aRacer Mini5 ECU is a great system that can do much more than you need, right now. A piggyback controller like a Dynojet PCV, Bazzaz Z-Fi or the "Enigma" comes with PC software that you use to add the proper amount of fuel to keep the air fuel mixture safe. So with the Enigma is everything written in Japanese and can you successfully tune with it? There are fuel maps available on the Bazzaz & Dynojet websites to get you up and running quickly. Is there any tuning help available with the Enigma or can you get a local shop to tune it? You don't want your mods to cause engine damage on your daily driver. Good luck.
 

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Discussion Starter #5
Hi again - and thanks for the replies!
Sorry for being away for a bit - it'll be like this, with my responses; I can't continuously monitor. I hope it's not a problem... Would like to keep the threads going...!
Lobot - very informative to me... It's fantastic to get a response from someone who has actually used the same parts I intend to use!
But it generates more questions:
1) I wonder why, then, Kitaco's own instructions state that you CAN use the stock ECU, provided you also use Kitaco's "Extreme R" exhaust system?
2) I still don't understand this inability of the stock ECU to "compensate" with the necessary enrichening of the mixture.
My retarded understanding - especially with non "wideband" 02 sensor, is that the ECU mainly sends signals to the actual EFI system, based on the variance from the 14.X/1 "ideal" air/fuel mixture, and the EFI injects more or less fuel bring the mixture within the range the ECU is programmed for.
In that case, as long as the mechanical/electrical EFI is physically capable of pumping the extra fuel required by any modifications to enrichen (and, I don't hear anyone saying that new injectors will be required...), then I don't understand why the ECU wouldn't just continue doing its job, read the 02 sensor, send the signals - unless the stock ECU is pre-programmed to only send a limited range of signals...

And to me, Kitaco has its own reputation to look after - they probably don't want folks burning up their engines with Kitaco mods - so, why would they make the statement that you can use the stock ECU at all?

Anyway, more of my own confusion!

Greg_E - I agree with you! My guess is it's a great way to make aftermarket $$ with "slip ons" - 'cause if you look at F1 exhausts, they're pretty much a consistent diameter from the port to the end...
I think the big cans are just to house the silencing muffler stuff...

Anyway, I think I'll be able to post photos of my SP Tadao pipe - I call it a "loop megaphone" because its can is megaphone-shaped, and to gain length, it has a loop between the port and the muffler...

Thanks again for responses, hope to hear/learn a lot more, and sorry it will take me while to get back...
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There is a science to exhausts, and a few calculators on the web. The loops are there to help keep some of the midrange at the sacrifice of the highest RPM power. Same goes for intake length. All of i has to do with the pulses and whether they are helping or hurting the process. Grossly over simplified.

The stock ECU could take a lot of change, assuming injector overhead, and assuming that they didn't lock the maximum injector pulse width to comply with emissions. But again due to emissions, the ECU is often limited in the amount of fuel trim it can program, many I've seen at +25 and -20 percent. Trimming that far without adjusting the base map generally signals an error, and that's one reason why the limit the trim. But emission compliance drives pretty much everything sold in North America, Europe, and Japan. Wish we could get an unlocked stock ECU and the software to tune it, but then we'd be getting into the Harley issue with the EPA.
 

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Discussion Starter #7
Thanks for the great info!
I've also finally done a little "due diligence" - I hate that stuff! - much rather be out riding...!
But I found this:

"BAZZAZ” is subcomputer that determines the amount of gasoline injected. It interrupts the computer and corrects the STD fuel injection map.
● In other words, the STD map, in which the fuel injection amount set according to the engine speed and throttle opening (and mixture ratio as signalled from the O2 sensor) is sent into the engine with the correction of ○% "thickening" and "thinning" of the fuel. It changes the amount of gasoline.
● Many standard vehicles have their original performance and ride quality suppressed due to various strict regulations, etc., and by adjusting the fuel with BAZZAZ, the suppressed performance and ride quality can be improved.

That's from my smartphone's translation from Japanese, of a description of a Bazzaz ZFI selling on Yahoo Auction ($600! - more than I want to spend...). I had to "fix" some of it - but left the "thick/thin" 'cause it's funny... ;-).
I added the O2 sensor part, 'cause it's another thing I learned...

So if I've learned properly:
the "pulse width" sent by the stock ECU to the FI system is likely limited by the factory "map" - and, once an engine requires more fuel than that (due to hi-perf mods), its incapable of having it delivered.

So at that point, a correction or a new ECU is needed.

So I guess I'm stuck with shelling out for one of these things, and learning how to use it...

... probably more, later -
Thanks again!
 
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