stupid question

[seespotweld]

does the fuel trim affect more than idle ?

[748R_bb155]

there a goot information on the weber marreli ecu at :

Sigma Performance - Weber Fuel Injection

Yes and does

EO

[seespotweld]

thanks for the info: took this from the sigma site ..still leaves a few questions ,like the last line. the chart did not copy well so I left it out .


There is one manual adjustment, the trimmer. This is intended to allow small adjustments in mixture at low revs. The chart below shows the effect the trimmer (either a small grub screw in the computer or a Program on a PC; depends on the computer type).

Note that a mixture change of 1.5% is required to move the exhaust Lambda by one point (i.e. from 0.90 to 0.91) so the available range is pretty large. While the trimmer will have some effect at high rpm it provides the inverse of what is needed to accommodate an open pipe or a freer breathing engine.

[TomTom]

On 1.6 and P8 the idle trimmer adjusts the injector duration with a fixed amount, for example adds 0.2ms, so it will have relatively more impact on short openings and vice versa. So it's pretty much useless to tune anything else than idle with.

[brad black]

s4rs, trimmer at -5, +25 and +55. going from -5 to 55 would make a massive difference to the idle mixture, probably stop it due to too rich.

[brad black]

800m with 25 points added to the trimmer. i haven't done this to any 1.6m or 1.5m bikes that i can remember.

[vij]

So the question is. How much is one point in mills secunds?
Afaik the marelli systems have a max injector time of 17ms.

I would guess that one point is 1/128 or 1/256 of 17ms.

If soo the smalles adjustmen would be 0,133 or 0,066ms.

Can some one confirm that or am I totaly wrong.

Jocke........

[seespotweld]

I have the vdst software which gives 128 points plus or minus ,mine seems pretty happy at plus 15 and barely runs at zero

[brad black]

1 trimmer point on a 5.9m is 3.6 times greater than a 1.5m trimmer point i'm told.

the smaller the pulse widths the bigger the effect. has a big impact on mv as the pusle widths are very small.