PCIIIusb "Accelerator Pump" Function

[Guest vkerrigan]

Thanks for the feedback Brian......Glad to hear it made such a positve improvement for you. I'll be having MPH install my usb version in the next two weeks (coupled with an ega tune) and was wondering if that feature worked as advertised. Appreciate the info............vk

[Guest gooddog]

pardon my ignorance, but just how is the accelerator pump beneficial?

[Guest Brian Robson]

ratchethack, Todd sent me a preinstalled map which is for open airbox and modified exhausts (which I have) and a Stucchi crossover (which I don't)...but it works great, eliminating the little pinging that I had.

goodogg, the pump on a bike with carbs added a little bit of fuel the instant the throttle was opened i.e.the throttle adding air, so that both were added together preventing any misfuelling. I think that Dynojet used this slight alteration to their mapping in order to give a little more tunability for acceleration without a rider being able to truly screw up the map, similar to the buttons on the device itself.

[Guest ratchethack]

Thanks, Brian. FWIW, I've got stock airbox and LaFranconi's and a Stucci X-over. Should be interesting to compare results. Will advise!

[Guest Brian Robson]

What does FWIW mean? :!:

[Guest John T]

What does FWIW mean? :!:

For what it's worth. AFAIK

[al_roethlisberger]

Why is this USB only?

 

 

"technically" specifically I can't say, but apparently the PCIIIusb is different from the old PCII/III not only in the addition of the USB port(as opposed to the db-9 serial)... but functionally as well.

 

One example is that the USB version uses twice the data points for it's map than the old PCIII, and has a physical expansion port inside for future functions like an ignition module.

 

al

[Guest Brian Robson]

I will know how the mileage is going tomorrow when I have to fill the tank, but I have to report on the pump software.

There was rainfall today after a lot of dry days and this made for slippy roads. I do ride regularly in the rain here on the Wet Coast of Canada, but I have found the LeMans to be the easiest bike to ride spiritedly in the rain due mostly to the forgiving power delivery.

This has changed with the addition of the pump software, the delivery is much more "direct" and there were a couple of little slides which at first were unnerving but after became quite pleasurable. I will leave the settings as is and get used to this change.

[Guest Brian Robson]

Just to add fuel consumption to the "data", and I'm not as sophisticated at the calculations as Al, I simply read the Kms when I fill up....I got 230 Kms today which is normal.

It may be that the gains made with only the PC111 are offset by the addition of the pump sotware...this is a plus because fuel consumption remains the same but performance and ridability are much improved.

Next tankful was at 255Km, so I think worse consumption is moot at this point.

[Guest vkerrigan]

Just had MPH in Houston install and tweak a PC III usb that I bought from GuzziTech. Todd E. pre-loaded a map to match the config of the bike and the boys @ MPH set up the accelerator pump feature for 80-20-20. I was not looking to increase HP with all this......only to eliminate pinging in the torque valley of 4-5k rpm in ambient air of >85 degrees. It was money well spent! My ride back to Dallas from Houston was in high 90s temps and I heard no pre-detonation at all, even when cranking the throttle wide open in 6th gear. In addition, my fuel mileage to Houston was 40mpg and the return was 41mpg. I would also echo the comments of others in saying that the bike just feels much more responsive than before. All in all, I'm very happy with everything and I'd like to thank Todd E. @ GuzziTech for the personalized service and a special thank you to Mike, Todd, Dave, and the whole crew at MPH for a great job and a very pleasant two days.

[al_roethlisberger]

Well, you can't make a much better case for the Accel-Pump feature than that!

 

 

 

 

Thanks

[Guest Bruce]

Permit me to add a couple paragraphs on accelerator pumps for curious minds. My first hand experience was with the one in cars back pre-emission controls.

 

The pump was nothing more than a rubber diaphram in a little camber filled with gas on the side of the carb. When you opened the throttle it would spray extra fuel into the carb's barrel. If you had the air cleaner off and looked down the barrel you could easily see it ( if it back fired while doing this it might burn your face off and set fire to the carb such is the price of knowledge). The mist looked Kinda of like from a spray bottle.

 

On the cheap junk I drove in my formative years the diaphrams would fail sooner or later. When this happened the car would run just fine at any one speed but when you'd try to accelrate it would really bog down. This was because opening the throttle without the extra fuel sprayed in caused it to be instantly very lean. So you'd have to accelerate very slowly while pissing off anyone behind you. Without the accel pump working the difference was quite dramatic, almost undrivable.

 

The same principles still apply. Open that throttle, you'd better be adding more fuel or it will be too lean. Maybe a little, maybe alot. So all fuel injection systems today have some sort of "accel pump function". They may call it something else but its there, has to be.

 

Of course running lean helps reduce emissions but if its off a little then it can cause pinging and reduce power ( sound familiar? ). What add on-computers allow you to make it richer as you please, that is you can control the accel pump function.

 

BTW there is a good basic article on pinging in the latest Motorcyclist. Marc Cook does a much better job than I ever could explaining what it is and why to avoid it. If your bike is pinging you need to read it.