no flies, no PC?

[martin_14]

I know this topic has been discussed ad nauseum, but it still doesn't look really clear cut when I hear the facts stated by many people in this forum, saying how the PC does actually take fuel away (leaning the mixture) at almost any RPM. However, that almost is never exactly explained and I was wondering if it means at low revs (< 4000 RPM), which is where the absence of the flies is mostly felt even by those who run the bike (even for a while) without adding the Power Commander.
I'd just like to recall what I can from what I've read so far here and see what you guys think:
- on a stock bike, I'd dare to say the misture is fat (rich) which helps drivability and cooling, specially at low revs.
- a fliectomy means basically leaning the mixture but, by how much? is it really compromising cooling and therefore engine life?
- those who took the flies out and added the PC: is the map still being leaned? that would be proof enough that the flies can be taken away without issues, right?
- many guys mentioned that because one thing or another, they took the flies out but couldn't install the PC until a couple of weeks later. In that transition time they did feel improvement, but the PC really brought up the benefits. Why? What improvements? what did the PC add to the equation?

A last thought would be: what are the changes in off/on throttle transition when flies out, and then when the PC is installed?
bring it on!

[Mister Tee]

I think the short answer is you will be leaned out significantly in the low RPM's where an "overly lean*" mixture isn't going to have an adverse effect anyway, and it will have a slight affect at high power/wide open throttle conditions due to the removal of a slight flow restriction of open secondaries.  Assuming you remove the shafts too, or you may not even remove that slight restriction.

*At high power, the most destructive air fuel ratio is actually slightly rich of stoichometric, corresponding to 25 degrees of EGT on the rich side of peak EGT.  You either have to run richer than that, or leaner than that to avoid damage.  Richer uses fuel to cool the valves and heads.  Leaner uses air.

[martin_14]

...  Assuming you remove the shafts too, or you may not even remove that slight restriction.

by "shaft" do you mean the one holding the flies? If I'm not mistaken, there is a sensor on it so the stepper motor can position it accurately, and taking it away would cause an error code, wouldn't it?

[jimmymac]

by "shaft" do you mean the one holding the flies? If I'm not mistaken, there is a sensor on it so the stepper motor can position it accurately, and taking it away would cause an error code, wouldn't it?

Not to metion the holes in the sides of your throttle bodys.

When you add the PCV, the front end stands up in second.
At least with aftermarket exhaust.

Either shift hard, or blip it over a slight rise in the road.

[rcannon409]

I tried my 08 in just the condition you described.  My pcv had not yet arrived and I needed to feel a before and after anyway.

SO, I removed the files and went for a ride.  Performance, and response was better than with the files in.  BUT, then I tried the pcv and immediately looked at the fuel moto map supplied for my bike.  The fm map adds fuel between 3250 and 5250.  Substantial  amounts between 5-25% throttle....just the range we cruise in.   

The file removal does add some hp and torque, no question about that, but if this is done right you also get better response and an easier to control throttle.  I'm not sure I woudl bother with file removal without the pc being added.

[Kazairl]

This is all from the map for my 2010 with  Leo vince slip on and no flies. Map by Fuel Moto

 Everything over 8k is all Negative Numbers. The rest are kind of spotty. Between 2k and 2250RPM  and under 20% Throttle there is an island of fairly significant positive numbers(highest is 32%) surrounded by negative numbers. And the rest of the map runs along the same lines. Islands of positive numbers or negative numbers surrounded by the opposite. 3500-7500 are mostly positive numbers.

 Now the map they provided for the flies in and just and Area P slip on shows pretty much all negative numbers with a handful of positive numbers.

 Take that for what you will.

 

[Son of Pappy]

I wish I could explain it better, but the - numbers are in referance to the zero map on the PCIII or PCV, they are not leaning out from the stock ECU.  FredH did a much better job of describing the effects, but I hope you get the general idea.  If I were any where near an Autobahn I would NOT remove the files without a fuel management device properly mapped. 

[Kazairl]

The power commander modifies the fuel signal sent to injector by whatever number you have in the corresponding cell. Say at 2000 RPM and 20% Throttle position the computer sends a signal of 100(hypothetical) to the injector. On your PCV map in that particular cell there is the number 10. This number is a percentage. It modifies the fuel command by 10%. So if you have a positive 10 the Injector will receive the signal to fire the injector plus 10%( In this case 110) or if you have a negative number -10%(In this case 90).

[B.D.F.]

Yep, that is essentially it. To expand on the idea just a bit:

The fuel injectors are basically and open or closed valve. PWM (pulse width modulation) is used to control how much fuel is injected; because the injectors will pass a known amount of fuel every second, then the "On" or open time of the injector directly controls how much fuel is used per engine cycle. An analogy might be a garden hose with an on / off only valve on the end; if the hose will deliver 1 gallon a minute, and you want 10 gallons, you would open the valve for 10 minutes. The same thing applies to the injectors, just a lot faster. They typically work in millisecond (thousandths of a second) or smaller increments and the control logic timing are extremely accurate in the 'ON' and 'OFF' time.

The fuel injectors themselves are really pretty simple and simply turned on by applying 12 volts. You could actually modulate the amount of fuel delivered with nothing more than a simple switch although we humans don't work on the millisecond level.

The Power Commander intercepts the 'ON' signal and changes it according to the throttle opening and the engine's RPM. If the ECU gives the injectors a 20 millisecond (0.020 second) wide pulse, and the P.C. has a + 20 in the map at the specific point where the engine is running when the pulse is given, then the pulse sent to the injector by the P.C. will actually be (20 ms + (20 ms X 1.20, or 4 ms) = 24 ms).

Fuel injectors are reasonably close to linear meaning that twice the on time will deliver twice the fuel, once the opening and closing time themselves are accounted for (the first 1/2 millisecond or so there won't be much fuel flow).

Brian

The power commander modifies the fuel signal sent to injector by whatever number you have in the corresponding cell. Say at 2000 RPM and 20% Throttle position the computer sends a signal of 100(hypothetical) to the injector. On your PCV map in that particular cell there is the number 10. This number is a percentage. It modifies the fuel command by 10%. So if you have a positive 10 the Injector will receive the signal to fire the injector plus 10%( In this case 110) or if you have a negative number -10%(In this case 90).

[rcannon409]

This would also assume the stock map was a good one..its not.  If this bike was my carbed yz 250, I would be changing the pilot, needle, and main to make it run well stock...with stock intake and exhaust.

Thats essentially what the power commander did.  So, if we go back tot he yz 250, you would be opening the airbox up and running the same jets. Not  a great idea.

The c 14 is so fast and powerful, its tough to decide how its running on the street as you are into the "go to jail" speeds in 7-8 seconds.

[gPink]

This would also assume the stock map was a good one..its not.  If this bike was my carbed yz 250, I would be changing the pilot, needle, and main to make it run well stock...with stock intake and exhaust.

Thats essentially what the power commander did.  So, if we go back tot he yz 250, you would be opening the airbox up and running the same jets. Not  a great idea.

The c 14 is so fast and powerful, its tough to decide how its running on the street as you are into the "go to jail" speeds in 7-8 seconds.

yeah cool. Also called sh!t eating grin speeds.

[rcannon409]

As a follow up, I asked fuel moto for  a map that included the Leo Vince, but with the quiet insert removed.  They told me the map I have was made with the insert out.  So I yanked it. Man, were they right.  More power, response, everything.

I will probably leave the insert in since I love the lack of noise, but the  leo vince flows about as well as an area P with a giant Potato jammed in the outlet.

[Kazairl]

Are you comparing slip on - slip on or the full system?

[rcannon409]

I have the slip on Leo. I dont know if they even make a full system for this bike.
Heres an odd thing.    I also have a Leo slip on for my sv650. I bought it since it was on clearance at 75% off. It looks better than the stock suzuki pipe and is lighter.  It too has a quiet insert.

SO, I compared the inserts. They measure identical except the suzuki-leo insert is an inch shorter. Diameter, and inside diameter are the same.  I put it in the concours and it runs very well, yet the sound is more quiet than no insert.

No idea how much Leo Vince charges for these, but we may have  several different inserts to experiment with.

 

[rcannon409]

I had a chance to take a good ride this weekend.  300 miles of varied terrain. In the city to twisted, two lane roads.

Gas mileage is up  some.  Its hard to compare since no two tanks get ridden with the same, but 5-8% is close.  I also notice the fan kicking on less as well .

I've played with the inserts and without, but I'll probably leave the original insert in. The bike is virtually silent and plenty powerful.  There is more power without the insert, but it would be difficult to use and be able to keep a drivers license.

The Fuel Moto map and pcv is a great mod. Vastly improved low rpm response.  The pcv would be a terrific product if it added no power.