Sport Button thoughts.

[The Gorilla]

Hi,

Cantfind1- Quote-

''Agree to disagree mate. the throttle opening in normal mode is the same as in sport mode there is no more air going in the engine for a given throttle position. Its just that in sport mode that given throttle opening happens with less pedal travel.'' End Quote.

For the Throttle Butterflies to open quicker in
the mid range for the same throttle
pedal angle input, which the Throttle Angle change does,
then Greater air volume must be required to give more
revs over the same time period.

Any engine requires more air and fuel to make
more revs over a given period.

ie] Sport Off and then Sport On.

Air velocity [so volume] to a point, must in the first part increase
as the throttle Butterfly has opended further with
Sport on than with Sport off, for the same throttle
pedal distance travelled.

This process requires a greater air volume for
the same duration which in turn
requires more fuel.

There is no free lunch.

Regards,

The Gorilla.

[alexk]

Gorilla bravo

[shimmy]

Originally Posted by alexk

Gorilla bravo

I never trust a man who can't even do [/quote] button correct , he can't be technically capable at all!

[glendog74]

Originally Posted by shimmy

I never trust a man who can't even do quote button correct , he can't be technically capable at all!

[shane@mbtech]

Originally Posted by The Gorilla

Hi,

Cantfind1- Quote-

''Agree to disagree mate. the throttle opening in normal mode is the same as in sport mode there is no more air going in the engine for a given throttle position. Its just that in sport mode that given throttle opening happens with less pedal travel.'' End Quote.

For the Throttle Butterflies to open quicker in
the mid range for the same throttle
pedal angle input, which the Throttle Angle change does,
then Greater air volume must be required to give more
revs over the same time period.

Any engine requires more air and fuel to make
more revs over a given period.

ie] Sport Off and then Sport On.

Air velocity [so volume] to a point, must in the first part increase
as the throttle Butterfly has opended further with
Sport on than with Sport off, for the same throttle
pedal distance travelled.

This process requires a greater air volume for
the same duration which in turn
requires more fuel.

There is no free lunch.

Regards,

The Gorilla.

But throttle opening % will yield same AFR whether sport on/off. The sport button just changes the :to: relation between pedal and throttle.

Cause and effect- obv throttle open wider changes fuelling, but is that not merely an effect of the cause- which is pedal % relationship to throttle %.

The fuelling is merely altered because the throttle has opened further. Regardless of whether you pressed pedal further or pressed sport.

I personally do not think it changers the fuelling directly, fuelling changes because of throttle opening wider/quicker.

I think the only alteration is in the pedal signals and that alone.

but if the primate can show me BMW techincal data to suggest otherwise then i stand corrected

Not an arguement, just discussion

[cantfind1]

Originally Posted by lawsy

But throttle opening % will yield same AFR whether sport on/off. The sport button just changes the :to: relation between pedal and throttle.

Cause and effect- obv throttle open wider changes fuelling, but is that not merely an effect of the cause- which is pedal % relationship to throttle %.

The fuelling is merely altered because the throttle has opened further. Regardless of whether you pressed pedal further or pressed sport.

I personally do not think it changers the fuelling directly, fuelling changes because of throttle opening wider/quicker.

I think the only alteration is in the pedal signals and that alone.

but if the primate can show me BMW techincal data to suggest otherwise then i stand corrected

Not an arguement, just discussion

Got it in one mate.

[glendog74]

I like goats.

[The Gorilla]

Hi,

Lawsy- No, sorry I do not have access to
any BMW Technical Papers on this.

I understand that your point is that the
AFR is linear in that the % ratio of air to fuel
is constant over the duration of the throttle
opening.

ie] the throttle butterflies travel the same distance
regardless if the Sport Button is on or off.

If I understand what your saying correctly
is that with Sport Button on the
same amount of fuel and air is used in
a shorter period ?

My Point is that with the Sport Button on
the throttle butterflies travel
a greater distance for the same % of pedal input
and as such the fueling has to be increased
to compensate for this.

This requires an increase in air velocity as the air
volume required has to be of a greater charge/volume
than if the Sport Button was off.

An increase in air velocity charge/volume will
also require and increase in fuel.

As the Standard M3 uses a Blade type MAF then
its fueling is via air volume /flow sensor, no matter
if the Sport button is on or off.

A Standard M3 is still subjected to the same
throttle angle change when sport is engaged
but is no where near as on/off to drive as a CSL.

20 or so BHP would not make that sort of difference
but an increase in fueling will.

As you know CSL MSS54 ECU does not use a MAF it uses load
with a TPS and a pressure sensor, and is also
why I believe that the fueling is altered on the
CSL.

Regards,

The Gorilla.

[outnumbered]

I think you're nearly both saying the same thing, but I must be missing some nuance of where you might be disagreeing.

My understanding is that the throttle pedal controls one thing directly, which is the amount of air getting into the engine via the throttle butterflies.

The ECU is always trying to maintain the most efficient air/fuel ratio, so will alter the amount of fuel injected to try to exactly match the amount of air going in (along with input from other sensors like engine temp to get it right).

In sport mode, the throttle butterflies open wider for a given amount of pedal travel. Hence more air in, hence more fuel in.

[glendog74]

My head hurts