I see your point, but i don't agree with the logic. To be able to use the %100 of the butterfly you would have to have full fuel curve maps and a customizable SAFC setup because you are still running off of computer controlled primaries.

long story short, the computer doesn't really care how much your exhaust flows....it is only going to give you soo much fuel unless you tell it otherwise.

 

BRING IT ON! The rev-hang really makes the car seem slower than it is... and that is a bad thing for our Fits!

 

The car uses the mass air flow sensor and oxygen sensor to determine the amount of fuel to provide. As long as it's within the parameters of the stock program the car will provide extra fuel to match the extra airflow. That's how the car adapts to different elevations and temperature and why they don't run lean and grenade with higher flowing exhaust.

Only a dyno test with one of these will answer the question, but I can see that it is possible to make more power.

 

Yes, i hope people arent getting all bent out of shape because it only reads 80. This is NOT the percent that the TB is open. It is the percentage of voltage that it received compared to the reference voltage. If it read 100 there would be a short and your sensor or TB would be BROKEN. Notice when the car is idling and the throttle is at 0% open... or closed. it reads 7-9. Its how the system works. The PCM knows that 7-9% of reference is closed (as well has using the IDL contacts on the TPS) and that 78-82% is WOT(as well as the WOT contacts on the TPS)

Go plug your scangauge into a cable throttle car. It will read more or less the same (depending on the manufacturer).

The throttle body opens WOT when you go WOT... as long as you are not over loading the motor(going up a hill, or 50mph in 5th) It wont go past the point of peak efficiency. On a cable car you can open it 100% but it wont accel any faster, itll just dump more fuel. The fit and DBW saves this gas and knows under the current conditions that the maximum opening that will do anything and will open it to that setting even if you are WOT.

These throttle controllers do seem interesting by making the range larger and upping the voltage. Id be interested to see how they do once they are released.

EDIT: To the post above me. The fit uses a MAP sensor and a IAT to determine how much air and o2 is entering the motor not a MAF.

 

Mike, I have to disagree with you on WOT percentage.
As posted earlier in this thread, I used AutoEnginuity software ( AutoEnginuity® - OBD2 Scan Tool - Professional PC and PDA Diagnostics ) and my laptop to experiment.

I agree with you that at idle it does read 7-9% however when you shut the engine off but leave ignition on, for a few seconds before the whole thing goes to "sleep", butterfly will go to 0%. With ignition on and engine off, butterfly servo is energized and you won't be able to push the butterfly open (without forcing it and breaking something!). If you go from engine on to ignition off, system will be "alive" for a few seconds allowing you to push the butterfly with your finger to a point where software will read 100% before everything goes "asleep".

I agree with you that 78-79% is WOT for Fit ECU because fuel mapping will be exceeded and like you said, it won't inject any additional fuel required beyond 79%. Remember everybody, Fit is engineered for mileage not performance. Unlike my CRX where they "built in" higher mapping value for beyond factory air box flow, in a Fit they did not! That is why Mugen did not bother with aftermarket filter options beyond higher flowing insert for factory air box. They obviously know more than we do about OEM ECU/ electronics limitations. With that said it is obvious to all of us that more can be extracted from this 1.5L, but it will require a lot more extensive electronics mods that Honda's of the past. Problem is, even if we get the butterfly to open 100% along with aftermarket filters/ram air giving it a lot more air, we won't get any additional fuel required to keep stoichiometric ration proper causing lean operation that will ultimately cause terminal engine damage. Piggyback fuel systems have their limitations (might require higher flow fuel pump, injectors,.....) and stand alone systems cost even more (might require even higher flowing pump and injectors even more due to greater power gain potential) . Everybody has their own threshold on where to set a spending limit vs. gain.

The more I read about Fit, the more I am sure that the only benefit of any form of throttle controller (regardless of the complexity and expense) we will get is more responsive gas pedal within OEM power band and nothing more or above that. Car might gain few milliseconds in acceleration from butterfly opening sooner just like in OEM "S" mode vs "D" mode on A/T Fit.
That means that even A/T Fit will benefit some more with these gadgets, but question is how much and is it worth the extra expense.
So for now I am and all ears!

Ivan

 

hmmm interesting, however it goes against what I have learned in all of my classes and i have first hand experience with my 98 hatch. WOT was 82%.... and it was definitely all the way open with the cable. You mentions at idle it drops to 0% i believe this is because it of how the electronics work. I am not expert so i may be wrong. Im willing to bet that if you took the intake arm off, idle then shut it down i dont think the butterfly would close anymore. Likewise with if before it went to sleep you put the pedal to the floor and see how far it opens. I will do this this weekend If i have time.

 

Same here my friend! My "working on cars for living" days are way behind me! I did not follow with the changes on modern cars with their electronics. I was happy to just drive them without having to work on them for quite some time now! For me it is not as fun anymore when you have to plug laptops. It takes old fashioned troubleshooting out of the equation. It created a lot more "part exchangers" than true mechanics! Sad! I compare it with medical stuff. Why cure something by looking for initial cause when we can cut it off! That is why surgical technology advanced so much faster than prevention medicine! they can charge more for surgeries anyway!

There are some current technicians here on FF that can shed a lot more light on the subject than I can. I am just describing my observations with my A/T Fit. I do not know if presence of A/T tranny vs. manual makes any difference the way butterfly reacts thanks to additional necessity for a tranny control.

Further on our butterfly research, to answer some of your questions this is what I noticed:
Guys, before you start messing with the butterfly, MAKE SURE YOU HAVE SOMETHING TO RESET "THE CHECK ENGINE LIGHT" BECAUSE YOU WILL THROW ONE ON!

Ivan

 

wow, good find. Tagged for interest.

 

ciburri: i actually was a honda tech for a little while, didnt pay nearly enough. Hopefully i get my new job

Ill do some experiments this weekend and post my findings

 

The Jazz/fit does NOT have a MAF it has a MAP sensor instead.

 

any news on these products? are they released? will they work for usdm?

thanks for the updates...
dave

 

yea seems everyone lost interest in the topic.
when u guys are checking ur scanguages for throttle percentage, make sure ur driving and have a load on the engine and check the percentage

 

Still keeping tabs on it, but in all honesty there hasn't been anything new to write about as nothing's changed -- the units are available and none of the JDM owners would have a clue if they work on our cars, so it's at a stand-still. Unless some brave soul picks one up to try on their ride, that's probably where things'll stay for a while. Maybe once I pay off some things on my cc I'll be the brave soul, but I have to wait a bit for now.

 

yea i got u, im just hoping it works cuz the market for the fit needs to get more products soon. thats the only thing making me want to get rid of the fit and get something better lol

 

haha i just found this..i want it but im broke ..is it compatible with USDM FITS?

 

Apparently so. Blitz is selling them here and there was a group buy put together for it. The one member that tested it out for Blitz was quite impressed.

 

So far what I have been able to deduce from this thread thread is that, there is little that can be done to these little upscale econo boxes to produce hard numbers that show performance gains. The best that can be hoped for is that the throttle controller that is being discussed does provide a noticeable increase in acceleration and makes the car more enjoyable to drive. You also will use more fuel, but the unit has 3 settings and can be switched off. It is also easy to install. Life is full of compromises, therefore when you consider the price of most things in life that you will spend hard to come by money for, and the time that you will spend behind the wheel, I would consider this better than spending the money on cosmetic eye candy.

 

i recoment you buy it i love it..you actually feel ahuge difference..i know i did even my friends did..it was the best buy i have payed for, for this car

 

I have a question. Were there any surprises with the cruise control, or does it still work like before. Thank you for your feedback, I am strongly considering purchasing one, soon.

 

the cruise control still works like before but with this little piece of heaven the car accelerates quicker on the highways...mpg goes down a little, nothing to crazy. I made it from Newark, NJ to Boston, MA with almost half a tank idk how good that is but i was doing atleast 75mph the whole way down with a little 100mph spirts here and there ...its just a good buy