yet another reason to drive manual. clutch pedal or neutral gear is very natural to reach for, even in an emergency. that said, i can imagine a sudden full throttle at the wrong time could catch anyone off guard.
speaking of throttle cables, they have a failure rate too, stuck or broken... i guess stuck at full throttle would be very unlikely though.
tuna55 wrote:JoeyM wrote:If you could still stop the car with the brakes at WoT, it is still driver error.novaderrik wrote: i thought it was floormats and driver error?If you could shift into neutral, it is still driver error.
Actually, if the brakes are already faded from having ridden them for a while, they probably wouldn't stop the car. Have you had brake fade on the track before? It's like, suddenly, no brakes! So exciting. And if the car is just sort of accelerating your first instinct, especially as a general member of the public, would be to ride the brake until it's slowed down. At 60+mph it would heat them up pretty quick. Then by the time they realize something's wrong, and they're hard on the brake, it's too late as the brakes are heat saturated and quickly lose effectiveness.
I felt the same as you until I realized that all the "stand on the brake and the throttle and the car goes nowhere" tests are actually not real world scenarios. A real world scenario is just too dangerous for us to actually test. That would be, get up to 65 mph and hold the brake and the gas part way for several minutes, then peg the gas with the brake gently pressed for a while until you get to 100+ mph, then peg the brake and the gas. You feeling lucky??
In reply to dculberson:
Also, in most modern vacuum driven brake boosters, WOT = no vacuum = nbrake assist, so good luck with that.
This thread is dejavu all over again...
accordionfolder wrote: In reply to tuna55: With actual cars on dynos they could reliably make it accelerate with the driver flat on the brake and off the accelerator. I agree, we'd see more if it was a common case, but that's pretty messed up.
Was this with some normal operating procedure or with some kind of link into the system inputing the faults?
4cylndrfury wrote: In reply to dculberson: Also, in most modern vacuum driven brake boosters, WOT = no vacuum = nbrake assist, so good luck with that. This thread is dejavu all over again...
http://www.edmunds.com/car-safety/could-you-please-stop.html
Edmunds wrote: As the first test was a standard stopping test, there was no drama — accelerate to 60 then mash the brake pedal. The stopping distance was 119.9 feet. ... The third test simulated a racing engine causing the car to speed out of control and the driver reacting by just hitting the brake pedal as hard as possible. Even though in this case the brakes had to overcome the motive force of the engine, they did. The car came to a halt in 148.8 feet
Well lookie there, I was proven wrong ... by Edmunds. Congrats, once again.
Most boosters have enough reserve for a couple of stops. You can still stop the car with no boost, just have to push harder.
Are you saying that things could go wrong in our computer-controlled future? Heavens! Who would have guessed?
That was a really good article, thank you for sharing it and your insights as a programmer. I find it very interesting that Toyota was found guilty in the Oklahoma case, and it may well lead to a lot more financial pain for them. Based upon the findings by the experts in actual firmware, they deserve it. Only nailing 6 programming rules out of 93 required?!?
Edmunds wrote: ... The third test simulated a racing engine causing the car to speed out of control and the driver reacting by just hitting the brake pedal as hard as possible. Even though in this case the brakes had to overcome the motive force of the engine, they did. The car came to a halt in 148.8 feet
Yeah, sure, if you jump on the brakes right away, the car stops fine but I think a MUCH more typical reaction would be to start riding the brakes rather than just stand on them. Hell, I'm sure I would while I evaluated the situation. How long will a Camry's brakes dissipate 200hp (or whatever) before turning to smoke? That's 150kW, equivalent to about SIXTY 8" electric range burners. A lot of heat.
mfennell wrote:Edmunds wrote: ... The third test simulated a racing engine causing the car to speed out of control and the driver reacting by just hitting the brake pedal as hard as possible. Even though in this case the brakes had to overcome the motive force of the engine, they did. The car came to a halt in 148.8 feetYeah, sure, if you jump on the brakes right away, the car stops fine but I think a MUCH more typical reaction would be to start riding the brakes rather than just stand on them. Hell, I'm sure I would while I evaluated the situation. How long will a Camry's brakes dissipate 200hp (or whatever) before turning to smoke? That's 150kW, equivalent to about SIXTY 8" electric range burners. A lot of heat.
Exactly. Like I said in my post earlier it's more complicated and involved than just mashing on the brakes once.
So, just to recap:
Bosch is the company making the GOOD stuff and Denso (with Toyota proprietary crap) is the BAD stuff?
The sky is black right now because it's dark out. It is bluish during the day. Is that the way it's always been or has there been a change recently?
dculberson wrote: A real world scenario is just too dangerous for us to actually test. That would be, get up to 65 mph and hold the brake and the gas part way for several minutes, then peg the gas with the brake gently pressed for a while until you get to 100+ mph, then peg the brake and the gas. You feeling lucky??
As an aside, when I had my A2 chassis Golf, it was so light/stiff in the tail that it would bounce all over the place on unplowed yet well-traveled roads, until I realized that applying some braking would settle it down.
So I ended up driving WOT in 3rd gear and control speed with the brakes, and it was stable like you wouldn't believe at 75-80mph. The rear drums would be steaming and the front brakes smoking slightly when I'd get to work.
Uh, I mean when I'd get off the track. Yes, that's it.
A friend of mine had the throttle on his z32 300zx jam open on him once at wot in third gear. The pcv hose popped off and wedged itself against the throttle. Fortunately he cut the ignition, slowed the car down and pulled over without incident. Nothing is bulletproof and unfortunately people like us that are willing to put effort into improving our driving skill are in the minority.
PDF is down, cant find an alternate source, somebody want to upload it somewhere?
MCarp22 wrote:4cylndrfury wrote: Do me a favor, find neutral in this thing when youre having an OHBERKME moment of epic proportions.Presuming the shifter is in "D" then N is still straight forward one click. You don't even have to look.
is that shifter actually hooked to the transmission with a mechanical linkage of some kind, or does it just send a signal to the same ecm that's causing the car to go WFO telling it that you would like it to please consider maybe taking the trans out of drive?
these new cars need a big, red panic button in the dash that physically shuts off power to the whole car when it takes off on it's own... battery cutoff/kill switches have been on racecars for decades, maybe it's time for yet another race car innovation to make it's way to the highways of the world..
True fact: In a late model Mercedes with the wundershift gizmo, it will slam it into Park when you open the driver's door. Even if you're in motion.
I found this out at walking speed. Scientific curiosity in seeing if there was a maximum speed for this "feature" was tempered by not wanting to mess around with someone else's vehicle.
However, if a GRM reader owns one of these vehicles, or finds himself in one and doesn't have an enlarged mechanical sympathy gland like I do, please... let us know if it will ram it into Park at 35mph if you crack the door open.
probably won't let you open the door...
Regarding original post:
Interesting stuff. But it's completely opaque to me. All i know is that if my Prius goes apeE36 M3 and starts giving me all 90-something hp when i dont want it, i will firmly depress the brake pedal while steering to a safe area, and when the car quickly comes to a controlled stop (which it will), i will put it in park and turn off the power. And continue living.
Granted, if it was a 270hp 2GR v6 car, it would take incrementally longer for the brakes to bring the car to a controlled stop. But they still would.
In reply to Vigo:
You are not a typical driver, you know how to work a set of brakes hard without boiling the fluid and/or catching them on fire. Most people, if they were in a calm enough state to do anything, wouldn't get on the brakes hard enough. You also likely religiously maintain the safety gear on your vehicle, buy good brake pads, keep your sliders lubed, and maybe even change the brake fluid before the calipers are full of watery goop.
It was also brought up, in the Reddit commentary I think, that depending on how tied to the ABS/TCS system the ECM is, a computer crash might jam all 4 solenoids on and leave you with no service brakes. Typical drum in hat parking brakes are not going to stop you from 70mph with the engine fighting them. Or in a realllllllllllly unlikely ultra worst case scenario, it could jam the solenoids on AND fire up the pump locking all 4 and probably putting the car into a spin.
In any event, the solution here is really simple. Either A: Mandate that all control systems be mechanical. or B: Mandate that any "by wire" system be built to aviation standards, IE, discrete quadruple redundancy on ALL levels throughout the system, 4 computers, 4 input sensors, 4 motors all strong enough to do the job alone.
i bet the newer electronically activated parking brakes would be even less effective at stopping the car if the ecm doesn't want you to apply them..
In reply to novaderrik:
Aw hell, I forgot all about that!
4cylndrfury wrote: software driven components that replaced reliable as gravity mechanical ones...to save pennies...this is what happens
Whats ridiculous is if you compare these cars to the 80s, and adjust for inflation, cars back then were significantly cheaper as well. If it's to save pennies it's definitely to rip the customer off as well.
Maybe these companies need to find a way to make cars die sooner since they don't rust anymore.
man i love my 93 bronco...
In reply to kanaric:
Cars were cheaper in the 80s on back then because they were just cars, more or less built as the car companies saw fit. Then regulations and the stupid concept of asking people who don't know what they want, what they want. So today you're forced by the government to buy at minimum two airbags, crash safety tech, traction control, and throttle by wire. And you're either buying or heavily subsidizing all the stupid gizmos you can get in a car now because the general public thought they wanted them.
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