Avti, ki nimajo potovalnega računalnika

Spajky je 12. jan 2015 ob 15:00 izjavil:

Avto ti po hribu navzdol lahko pije O L dejansko le, ČE ga custom "zmodificiraš" ala jest, drugače (originalno) pa NE !!!
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Pa ne verjet vsemu, kar vam kaže tisti kao potovalni računalnik ...

Potem pa razlozi tole:

Na mojem bivsem BMW 525i je pri voznji na klancu navzdol prislo do osciliranja obratov okoli vrednosti 1500, ce sem imel nogo odmaknjeno s pedala za plin.

- Nad 1500 obrati je BC kazal porabo 0, hitrost vozila je padala, stevilo obratov se je zmanjsevalo do nekaj pod 1500.
- Ko so obrati padli pod 1500 je BC zacel kazati neko nenicelno porabo, hitrost vozila se je zacela povecevati do nekaj nad 1500, kjer je BC spet padel na 0.

Ta cikel se je ponavljal dokler je imel klanec primeren naklon (razlicen za 1. in 2. prestavo - v ostalih nisem sprobaval).
Cim sem se pa samo malenkostno dotaknil pedala za plin, je bilo z zaviranjem na taksnem klancu konec - hitrost se je samo povecevala.

Podobno je obnasanje na motorju (Honda Hornet 900). Ko prestavljam na dol, se motor drasticno drugace obnasa ce imam plin popolnoma zaprt, kot pa ce ga imam za milimeter odprt (v prostem teku to pomeni morda 20-30 vrtljajev nad prostim tekom - zanemarljivo).

Ce je plin popolnoma zaprt, in na hitro prestavim in spustim sklopko, motor "cukne" - v visokih obratih dovolj, da na slabem cestiscu guma zacvili. Ce pa imam plin samo malenkost odprt, je reakcija bistveno bolj mehka in dosedaj mi se nikdar ni "zacvilil". Edina razlaga je, da ECU v prvem primeru vidi, da je plin (t.j., lopute v sesalnem kanalu) zaprt in ne dovaja NIC bencina. Cim pa je plin malenkost odprt, pac ne ve, da zaviras, ampak mora delati stoihiometricno mesanico, s cimer pac dovaja bencin in s tem bistveno manj zavira.

Ko sm gledal to oddajo mi je šlo na kozlanje. Človek je vozil v leru in zaviral, itak da je porabil več pa še bremze kuril. S pametnim lerom bi porabil manj in nič več zaviral.

Ja, "naj bi" nisi niti približno dovolj povdaril.

Spajky je 13. jan 2015 ob 21:41 izjavil:

... drugače pa vsaj minimalna je ... ni važno al je dizel al bencinc ... drugega ne morem reč kaj dosti ...

Slabo si informiran.

Overrun Fuel Cut:

When the throttle is abruptly closed the engine generates more vacuum than under normal conditions (such as idle and light cruising). This condition is known as overrun. During overrun the ECU performs a fuel cut by switching off all injectors. This helps minimise the possibility of backfires occurring and reduces fuel consumption and emissions.

Volkswagen-ova stran "Be aware and save fuel. Think Blue" na njihovih spletnih straneh ustainabilityreport2013.volkswagenag.com, stran 8:

Just let it roll. Use overrun fuel cutoff

With the right driving techniques you can really start saving. Do you know how to achieve precisely 0.0 l/100 km for “current consumption”? By coasting with the car in gear!

Overrun fuel cutoff interrupts the fuel supply to the engine and during that time you won’t use a single drop of fuel. The best time to apply this clever method is when you can also benefit from the braking effect of the engine – i.e. on a downhill gradient or when approaching a red traffic light.

TPS Parameters na strani Hondata - Honda ECU Modification and Enhancement:

Overrun Fuel Cutoff (TPS)
This controls the point where the injectors are cutoff at low throttle openings.
Throttle - sets the throttle opening where injectors are cut. This needs to be higher than the minimum TPS reading - between 0.5 and 1% usually works. well.
Delay - sets the delay between the throttle closing and the injector cut.

Overrun Fuel Cutoff (MAP)
This controls injector cutoff from low manifold pressure.
If the injectors cut off early, resulting in jerkiness, decrease the MAP pressure. Usually 15 - 19 kPa for 500-4000 rpm works well.

Overrun Fuel Resume
These tables control the point where the injectors resume after fuel cutoff from overrun.
Minimum reading - is the default TPS reading when the throttle is fully closed. The Set button
Maximum reading - is the default TPS reading when the throttle is fully open.
Read - reads from the ECU and sets either the minimum or maximum throttle to the current TPS reading. When setting the minimum reading, ensure the throttle is fully closed, when setting the maximum, open the throttle fully. This should be not be done with the engine running.
Defaults - resets the minimum and maximum settings to standard defaults

New Chrysler system puts the clamps on fuel consumption (nekaj desetletij po BMWju):

One of the most logical ways to save gasoline is not to use any at all. That’s the thinking behind Chrysler’s Interactive Decel Fuel Shut Off, or iDFSO, which turns off the fuel supply when it isn’t needed.

Many automakers use similar technology in their vehicles. Chrysler puts it on a number of engines in its Chrysler, Dodge, Ram and Jeep brands, on both V6 and V8 configurations.

Engines run when gasoline vapour is injected in and then exploded by the spark plug. The resulting energy moves pistons, which turn a central crankshaft; that shaft’s spinning motion is transferred through the transmission and drive shafts to turn the vehicle’s wheels. The crankshaft revolves at all times when the engine is running, but when you’re decelerating, the vehicle’s momentum is enough to keep it spinning. Since the engine is capable of running without gasoline due to this momentum, iDFSO temporarily shuts off the fuel supply.

Kar se mene tice, je debata okoli tega zakljucena.