There are many Eproms supplied with modified
standard fuel maps, you will typically pick them up free with exhaust systems or as factory accessories. There are however alternatives that bring significant improvements to the way
the whole system performs. The main alternative is FIM's Ultimap and Megazone system.
The Ultimap uses 'Megazone' technology to allow certain areas of the map to be 'corrected', be that richer or leaner, as the engine is used. Originally developed for racing the corrections
can be applied to a map in seconds, very effective in the pitlane or on a dyno.
FIM redesigned the operating system in the Weber ECU's unit to add extra functionality not supplied in the original Weber software. Many of the operating parameters were switched from
'constants' to 'variables' allowing a tuner to adjust them while the engine is running. Early P7's required an Additional Memory Board to permanently change the fuel parameters without
actually reprogramming a new chip. Later computers had either EPROM or Flash memory which was unused by Weber; these were used to
store extra fuel corrections, RPM telltales and so on. (Note; these additional parameters only work with FIM Chips as the factory Eproms ignore these locations.)
The Eprom itself is not changed but the duration of the fuel pulse it finally decides on can be
further changed by the trim factor dialled in by the Ultimap Diagnostics for Win95/98 programme (or for the older folk amongst you the famous Hand Held Terminal).
The new flashload technologies (1.5; 5.9 types) mean that the original computer can be reloaded with maps that suit the proposed use.
Ultimap Fuel Maps
Ultimaps are completely revised fuel maps designed to work with very particular engine set-ups.
They are built using bikes recently very accurately built to the specification required (typically just a really accurate standard setup) and include new primary and offset maps as well as
modified ignition timing, environmental trims and redlines. FIM's site has a full listing of the
options currently available. Adjustment can be achieved by using either the Hand held terminal or the new Ultimap Diagnostics for Win95/98 programme (which uses a simple security key and
allows you to modify settings using a normal Laptop, or other, computer).
Adjusting Ultimap Fuel Maps
All FIM UltiMap Eproms can be adjusted. This
system uses the map stored in the EPROM in conjunction with correction factors. There are two types of correction: Zone Specific Trims, and the Overall Trim. The Zone Specific trims
are switched within RPM and Throttle boundaries, and only one is applied at any time. The Overall Trim is a correction which always applies, regardless of the zone specific trim.
As the engine operates through different RPM and Throttle areas, one of the zone trims becomes active. When the engine revs through one of the zone boundaries, the adjacent zone
becomes active, and the previous zone becomes inactive. If the throttle position changes through one of the zone boundaries, then the higher or lower throttle zone becomes active and the
previous zone becomes inactive. The zone boundaries determine which zone is active.
Each zone can be used to make adjustments for particular engine problems, if the boundaries are set appropriately. Two sample maps are set out below; you will notice the way that the
perimeters of each zone can be adjusted, depending on operator preference. Please remember that the particular zone boundaries chosen for the example are just that, examples,
you can put the boundaries wherever you want, but the zone numbering system and broadly speaking the effect each has are the same……….
Let us examine a fuel map divided into nine zones and the effects that modifying them has:-
ZONE 1 - Start-up and Idle. Use this zone for setting the idle mixture so that the engine idles
correctly when warm. Normally you should not need to change this zone more than a few percent. If so, check that the fuel pressure is correct and injectors are clean. This zone is shown in Dark
Blue, and would be active at any throttle below 6.5 degrees, and when the RPM is below 3000.
Zone 2 - Closed throttle Overrun. Use this zone to eliminate backfires when changing down
through the gears, or when decelerating on a closed throttle. To reduce backfires it is normally necessary to richen the mixture by up to 12 %. This zone is shown in deep red, and would be
active at any throttle below 6.5 degrees, when the RPM is between 3000 and 4500.
ZONE 3 - Free Revving Throttle Pump. Use this zone to richen the mixture when revving the
engine in neutral. This zone is shown in red, and would be active at any throttle between 6.5 and 21.5 degrees, when the RPM is between 3000 and 4500.
Zone 4 - Cruise Midrange. Use this zone for medium speed cruising, and the initial part of
acceleration when already at speed. This zone is shown in good old purple, and would be active at any throttle between 6.5 and 21.5 degrees, when the RPM is between 3000 and 4500.
ZONE 5 - Accelerating into Corners. Use this zone for acceleration into corners where the
rider drops a gear to keep up the revs, and feathers the throttle for control. This zone is shown in dark orange, and would be active at any throttle between 6.5 and 21.5 degrees, when the RPM is above 4500.
ZONE 6 - Full Power through the Gears (Wheelstands). Use this zone for maximum acceleration through the gears. In this setup this zone would be active at any throttle over 21.5
degrees, when the RPM is between 3000 and 4500, shown in light orange.
ZONE 7 - Full Power Top Speed. Use this zone for maximum power in top gear at high speed.
This zone is shown in light purple, and would be active at any throttle over 21.5 degrees, when the RPM is above 4500.
There are two areas of the zone box
which do not have a specific zone trim. These are the area in the top left of the box (corresponding to full throttle below 2000 rpm), and the bottom right of the box (corresponding to shut
throttle above 4500 rpm). These areas are considered relatively unimportant in everyday use and therefore do not have a unique trim. However, they can still be adjusted by use of the Overall Trim
, which affects all zones at all times.
The second 'zone map' shows how the zone perimeters set out above can be changed and manipulated to allow modifications to be made to very
specific areas. This capability can be used very quickly, indeed we were changing fueling, and zones, on our 748RS in less than 15
seconds in Pit lane in 2000. The Zones can be set to any of the breakpoints, but only if the zone barrier is in a straight line across the map. The ECU updates the active zone over 100 times per
second and switches zones instantly, as the engine's revs and the chosen throttle position move.
For Flashload computers the map can unloaded by the Ultimap programme, remodelled by increasing (richening) or reducing (leaning out) each zone by a preferred percentage and then
reloading the map into the computer. This is slightly more time consuming then the zone adjustments set out above but the way in which the map would be remodelled for a specific usage would be exactly the same.
For more information on FIM Ultimap products hit here, for details of how to you get your bike set
up correctly by Sigma, including new fuel maps, hit here.
Neil Spalding and Duane Mitchell