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I have been upset with Toyota's designs, product quality, and business practices since I bought my first (and last) Toyota vehicle. Mr. Barr's testimony reassu

by kw71 11y ago

I have been upset with Toyota's designs, product quality, and business practices since I bought my first (and last) Toyota vehicle. Mr. Barr's testimony reassures me that I've made the right decision in writing them off. One item I'd like to point out is that Mr. Barr criticizes the lack of hardware logic to close the throttle if the driver rides the brake. In 1987, BMW introduced the 1988 model year 750i, with a V12 engine that has two intake manifolds and two throttle valves. The engine controls and electronic throttle system was made by Bosch. Whether the logic is in hardware or software, I don't know, but it doesn't take long for it to slam the throttles shut if you hold the brake pedal down. When this happens when the engine is delivering power, it's a very severe shock as engine power is removed and stops working against the brakes. Due to the time it takes to go to manufacturing from the design stage, obviously the Germans had this figured out in the middle of the 1980s decade. BMW went on to use the electronic throttle system in a bunch of 90's model 5 and 7 series cars with normal six cylinder engines. The only problems that I know this system, called EML, caused were for owners and technicians who did not understand how the system works. In other words, when this failed, the result was that the car would not go anywhere. And a colleague of mine with a late 90's Volkswagen also proved that the throttle slams shut if he rides the brakes while requesting engine power with the gas pedal. Mr. Barr points out that in 2005, the Camry had no such logic. I seem to remember a youtube video where Consumer Reports guys test this out in some kind of Toyota, and they could have gone all day long until the brakes melted. Toyota did not include this logic for safety even though it had been in cars released to the market decades before. The ways that Toyota handled this situation, everything they've done from blaming the operators, the potientometer supplier, the floormats, to their brazen delays in producing discovery, reinforce my bad experiences owning a Toyota and my conclusion that they are a bad actor.

pedrocr 11y ago
> And a colleague of mine with a late 90's Volkswagen also proved that the throttle slams shut if he rides the brakes while requesting engine power with the gas pedal. Maybe automatic cars do this but when driving a stick shift a common advanced driving technique is to heel-and-toe on downshift so that you can rev up the engine to the correct RPM to not upset the car. That requires revving up the engine under braking. As far as I know this is still possible in most cars. The usual guarantee is that the brakes are always specified to be able to overpower the engine even at full throttle. So even if you have a stuck throttle for some reason you should always be able to safely stop just by standing on the brakes, even if it takes you a little longer. Naturally in a manual car you should just stand on the brakes and clutch for emergency braking and then the engine is completely disconnected no matter what the throttle is doing. [1] https://en.wikipedia.org/wiki/Heel-and-toe https://en.wikipedia.org/wiki/Heel-and-toe
- serf 11y ago
  blipping the throttle while clutched to match RPM between the forced road speed and given engine RPM during a gear shift to alleviate weight-shift(heel-and-toe) is still possible on modern cars, but that is not the technique that is being mentioned. the technique being mentioned is more akin to 'left-foot braking', a technique used to pivot the weight balance from the rear to the front in order to induce certain driving characteristics that may be beneficial in a turn. It is a common technique to balance out the inherent understeer of a front-wheel drive car to a more neutral balance mid-turn in an effort to reduce lap times. It's quite common in rally.[0] and as was said, many cars disallow left-foot braking now; with the worst responses triggering semi-permanent CELs (CELs which require mechanic intervention, as opposed to being clear by more drive-cycles). Probably not a bad idea, as it's an advanced technique that quite easily upsets a car mid-turn, and is often just compensatory for an ill-setup race car. [0]: http://en.wikipedia.org/wiki/Left-foot_braking http://en.wikipedia.org/wiki/Left-foot_braking
  - sliverstorm 11y ago
    You're mixing up techniques. Heel-toe is so called because you are using your right toe to operate the brake and your right heel to operate the gas pedal (at the same time) while the left foot operates the clutch. The technique is used in racing during corner entry to allow the driver to rev-match downshift while under hard braking. This way they are already in the optimal gear as they release the brakes and initiate the turn
  - pedrocr 11y ago
    > the technique being mentioned is more akin to 'left-foot braking' Both heel-and-toe and left foot braking require revving up the engine under braking. The difference between the two is if the car is in gear and the clutch engaged at the time. Maybe modern cars have enough sensors to know if the engine is actually driving the wheels so they can disable the throttle under braking in those situations.
    - kw71 11y ago
      > Maybe modern cars have enough sensors to know if the engine is actually driving the wheels so they can disable the throttle under braking in those situations. This is possible, any car with traction control has wheelspeed sensors for all wheels, and manual shift cars have a pushbutton switch on the clutch pedal arm (for enabling the starter, or for a car with electronic throttle, for cancelling the cruise control.)

by kw71 11y ago

pedrocr 11y ago

> And a colleague of mine with a late 90's Volkswagen also proved that the throttle slams shut if he rides the brakes while requesting engine power with the gas pedal. Maybe automatic cars do this but when driving a stick shift a common advanced driving technique is to heel-and-toe on downshift so that you can rev up the engine to the correct RPM to not upset the car. That requires revving up the engine under braking. As far as I know this is still possible in most cars. The usual guarantee is that the brakes are always specified to be able to overpower the engine even at full throttle. So even if you have a stuck throttle for some reason you should always be able to safely stop just by standing on the brakes, even if it takes you a little longer. Naturally in a manual car you should just stand on the brakes and clutch for emergency braking and then the engine is completely disconnected no matter what the throttle is doing. [1] https://en.wikipedia.org/wiki/Heel-and-toe https://en.wikipedia.org/wiki/Heel-and-toe

serf 11y ago
blipping the throttle while clutched to match RPM between the forced road speed and given engine RPM during a gear shift to alleviate weight-shift(heel-and-toe) is still possible on modern cars, but that is not the technique that is being mentioned. the technique being mentioned is more akin to 'left-foot braking', a technique used to pivot the weight balance from the rear to the front in order to induce certain driving characteristics that may be beneficial in a turn. It is a common technique to balance out the inherent understeer of a front-wheel drive car to a more neutral balance mid-turn in an effort to reduce lap times. It's quite common in rally.[0] and as was said, many cars disallow left-foot braking now; with the worst responses triggering semi-permanent CELs (CELs which require mechanic intervention, as opposed to being clear by more drive-cycles). Probably not a bad idea, as it's an advanced technique that quite easily upsets a car mid-turn, and is often just compensatory for an ill-setup race car. [0]: http://en.wikipedia.org/wiki/Left-foot_braking http://en.wikipedia.org/wiki/Left-foot_braking
- sliverstorm 11y ago
  You're mixing up techniques. Heel-toe is so called because you are using your right toe to operate the brake and your right heel to operate the gas pedal (at the same time) while the left foot operates the clutch. The technique is used in racing during corner entry to allow the driver to rev-match downshift while under hard braking. This way they are already in the optimal gear as they release the brakes and initiate the turn
- pedrocr 11y ago
  > the technique being mentioned is more akin to 'left-foot braking' Both heel-and-toe and left foot braking require revving up the engine under braking. The difference between the two is if the car is in gear and the clutch engaged at the time. Maybe modern cars have enough sensors to know if the engine is actually driving the wheels so they can disable the throttle under braking in those situations.
  - kw71 11y ago
    > Maybe modern cars have enough sensors to know if the engine is actually driving the wheels so they can disable the throttle under braking in those situations. This is possible, any car with traction control has wheelspeed sensors for all wheels, and manual shift cars have a pushbutton switch on the clutch pedal arm (for enabling the starter, or for a car with electronic throttle, for cancelling the cruise control.)