The effect of riding position on fuel consumption

On my first 2k run on the GRiSO recently i noticed that (for me) the most comfortable way of doing a 300 mile day is to sit far enough forwards that my arms are gently bent and my knees are in the tank hollows. More supermoto than cruiser.  This means the footrests are a bit behind me so my feet hang down from the pegs by maybe 35 degrees, I had adjusted the gear pedal to this angle and I had lowered the brake pedal as far as i could - thought it was fine.

I was wrong.


Just around Ullapool i heard noise from the back on braking - turns out no pad material! had used 2mm of brake pad in 1000 miles

So i avoided the rear brake for the next 900 miles and found three things
1)  My natural foot positon (matching the left side) was below the brake lever
2) My measured at fill-up fuel consumption improved from 42.5 mpg to 48.5mpg (6.7 Lper100Km to 5.8 Lper100Km)
3) The dashboard fuel consumtion meter is hopeless - still reads 45.2mpg

To get the lever low enough for my riding position and avoid dragging the rear brake I had to remove 7mm of the threaded end of the brake operating pin and put a 5mm spacer on top of the stop light operating pad.

Now i have 48mpg and brakes that are only on when i want them to be

Check the tail brake light. Might be burnt too

Thanks Voulga - the stop/tail is fine

Mine is well serviced and not ridden hard, totally standard from new. I only get 35 MPG which annoys me a bit. I would be very happy with 45 and perhaps will get that after I do the beetle upgrade?

Humble 1200 is that 35mpg calculated at fill-up
or from the dashboard computer?
The dashboard computer is about 16% pessimistic on mine

lcjohnny wrote:

Humble 1200 is that 35mpg calculated at fill-up
or from the dashboard computer?
The dashboard computer is about 16% pessimistic on mine

You can spend the time and fix it up. Mine is accurate to +/- 0.15 l/100 km - it took a bit of fiddling though.

Oz1200Guzzi wrote:

You can spend the time and fix it up. Mine is accurate to +/- 0.15 l/100 km - it took a bit of fiddling though.

How?

Plz

Jon there is an adjustment in the mapping tool TunerPro. You need TunerPro and the XDF for your particular ECU (available through GuzziDiag).

I will have to look up the exact parameter, when I get home (from Work) as I don't have this installed on my work computer - or someone else can chime in...

I do know you will need to fill your tank at the same pump at the same lean angle every time, carry a notepad and record km, litres and your last setting in the map. You will need to be religious about this. You will also need the cables and GuzziDiag/Writer so you can upload the maps you change.

Found it - Fuel Consumption Scale Factor. In essence it is the "fuel consumption scalar for CANBus value. The reported Consumption shown in the dashboard in litres per 100 km is inversely proportional to the square of this value".

Decreasing the value (2000 as standard on a 1200 Sport with 5AM ECU), is a good place to start. I would start by going down 50 and see what gives with fills and calculations. If it's the wrong way, go the other way.

I purchased some Chinesium injectors and their flow rate was WAY larger than the unit it was allegedly replacing. I ended up around the 1700 mark to align with the reduced fuel injection numbers I had to fiddle with to get it close. I have since gone back to the original injectors as the issue was elsewhere (pitted valve faces).

You will never get it spot on as temperature, headwind, riding style and even your full level of your tank will all make a difference to the accuracy experienced. That's why you need to keep good records and hasten slowly.

Qu.Humble 1200 is that 35mpg calculated at fill-up
or from the dashboard computer?
The dashboard computer is about 16% pessimistic on mine.

A. Hi, yes. Taken from the dash. I can get about 130miles before going on reserve. I've never run it dry but if I assume 150m from full to empty that gives 41 MPG. That's a bit better. Thanks.

Thanks OZ1200
I will spend some time on that over summer
Need to be getting a steady fuel consumption first

Jon

I have started changing the 'Fuel Consumption Scale Factor' in custom maps using Tuner Pro

it is not a stricly linear relationship so I am having to use trial and error.

I need to do a few more miles to check whether i have it close enough now

Nb in UK we don't view fuel consumption (gallons per mile) but range (miles per gallon)
so the relationship on the graph below maybe the inverse of those who view Litres per 100km

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