Re: [MBZ] Sudden Acceleration Revisited
If you start to brake at 100mph, you are a fool. I think there is a lot of foolishness here. 3 Toyota's have crashed in Connecticut, attorney general is on a tear. I'd like to see Toyota take a few cars onto a test site and run them to 60mph and floor both pedals. The would put this issue to bed.. I'm betting a very high percentage of the cars that are being wrecked are owned by folks that are upside down in them anyway. It you need a car right now, by A 'yoda from a rental fleet, they are running away from them -- Pete Arnold 32° There are only three sports: bullfighting, motor racing, and mountaineering; all the rest are merely games. - Ernest Hemingway On 3/13/2010 12:34 AM, Jerry Herrman wrote: With your collective indulgence, I'd like to re-open the discussion of the topic sudden acceleration. You may recall in mid february I opened the discussion with this submission in vol. 51 issue 39, or thereabouts: ( So yesterday I heard what I believe was a public service announcement (by some automotive engineer, I think) on the radio saying that the least powerful brakes are going to easily overpower the most powerful engine.This suggests that applying your brakes firmly in an unexpected acceleration situation would prevent a catastrophe.) Responses from subscribers to this forum suggested that applying the brakes firmly and immediately to stop the car would be successful, regardless of the power output of the engine. Applying the brakes to merely slow down the vehicle, most concluded, would likely result in overheating the brakes to the point that they could be ineffective. The recent report of a Prius driver's scary struggle with sudden unexpected acceleration raises this topic again. I am taking no position on this issue. I am asking questions to better understand what is happening. Here are several questions that circulate through my mind. If a driver were to experience this phenomenon in a powerful car whose speed has gone well above 100 mph, would there be any hope of stopping the car using only the brakes? Can a Prius whose driver is trying to brake the car continue to accelerate? How powerful is the Prius engine? Can all cars be shifted easily into neutral in the event of this emergency? Is there any down side to turning off the engine in this situation? Having driven a 240D for many years, sudden acceleration sounded rather attractive . Now, not so much. Jerry 1982 240D 60+ horsepower __ Information from ESET Smart Security, version of virus signature database 4940 (20100312) __ The message was checked by ESET Smart Security. http://www.eset.com ___ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com ___ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Sudden Acceleration Revisited
Jerry Herrman wrote: The recent report of a Prius driver's scary struggle with sudden unexpected acceleration raises this topic again. I believe Hybrids are a special case, with brake by wire. You hit the brake pedal, the computer looks at the battery, the speed, and how hard you're hitting the pedal to decide what combination of regeneration and friction braking to give you. That's what the software flash on the 2010 Pious is about. What I don't know is if there is mechanical override. For example, if you hit the pedal for 200lb or so, does it activate the service brakes full on no matter what the powertrain computer wants? And how powerful are the Pious service brakes? And does the ABS have its own computer, or does the powertrain computer run that too? Whatever controls the ABS has the ability to turn your service brakes OFF. With my 1995 Taurus, the ABS was way too touchy, so if I wanted to actually stop for a stop sign on a snowy/icy road, I turned the engine off before hitting the brakes. I never felt the need to do that with the 1997 Achieva, but I did turn the traction control off at first snow and leave it off until spring. (when struggling to get through deep snow, the computer would detect slip and retard the timing, and I'd just push the pedal farther to keep the power where I wanted it. Then I'd glance down and see the trac loss light and realize it was wasting fuel fighting me. I think the Toyota problem is that in some cars, HAL has the ability to crash the spaceship against the pilot's best efforts. The Lexus that killed the California cop, you asked the computer to shut the engine off and the computer did it for you, if it felt like it. I'm not certain, but I also think it won't let you shift into neutral while driving down the freeway at high speed with the throttle to the floor. I still think if he was full on the brakes within a second of the unintended acceleration (I hope that would be my reflex), that Lexus would have STOPPED, unless the ABS decided to kill him too. That car has serious brakes. If shopping for a car, I'd find a fairly deserted road, floor the throttle at 40mph or so, and try to stop the car without taking my foot off the throttle. Killing the engine should be fine, provided you don't cycle the brakes with the engine off (push the pedal down and hold it down, don't pump it), but if the power steering is electric and you shut it down, it will become VERY hard to steer. I don't have a problem with hydraulic power steering, either recirculating ball or rack and pinion, but rack and pinion with the engine off is stiffer than recirculating ball. All my MBZ were designed in the 70s and 80s, so they are recirculating ball. Mitch. ___ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Sudden Acceleration Revisited
It sounds like the dude the other day was trying to hold speed with the brakes before they failed. So again, brake hard and hold until you win or crash... Most new cars have a computer controlled automatic trans so shifting in to neutral at 100mph with the throttle stuck would probably be an input the computer would ignore. Which is really the whole problem, the computer ignoring input from the driver I mean. -Curt Date: Fri, 12 Mar 2010 21:34:45 -0800 From: Jerry Herrman jer...@san.rr.com To: mercedes@okiebenz.com Subject: [MBZ] Sudden Acceleration Revisited Message-ID: 7719cd3ec59145558428a87ab8618...@jerrypc Content-Type: text/plain; charset=iso-8859-1 With your collective indulgence, I'd like to re-open the discussion of the topic sudden acceleration. You may recall in mid february I opened the discussion with this submission in vol. 51 issue 39, or thereabouts: ( So yesterday I heard what I believe was a public service announcement (by some automotive engineer, I think) on the radio saying that the least powerful brakes are going to easily overpower the most powerful engine.This suggests that applying your brakes firmly in an unexpected acceleration situation would prevent a catastrophe.) Responses from subscribers to this forum suggested that applying the brakes firmly and immediately to stop the car would be successful, regardless of the power output of the engine. Applying the brakes to merely slow down the vehicle, most concluded, would likely result in overheating the brakes to the point that they could be ineffective. The recent report of a Prius driver's scary struggle with sudden unexpected acceleration raises this topic again. I am taking no position on this issue. I am asking questions to better understand what is happening. Here are several questions that circulate through my mind. If a driver were to experience this phenomenon in a powerful car whose speed has gone well above 100 mph, would there be any hope of stopping the car using only the brakes? Can a Prius whose driver is trying to brake the car continue to accelerate? How powerful is the Prius engine? Can all cars be shifted easily into neutral in the event of this emergency? Is there any down side to turning off the engine in this situation? Having driven a 240D for many years, sudden acceleration sounded rather attractive . Now, not so much. Jerry 1982 240D 60+ horsepower ___ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Sudden Acceleration Revisited
In one case the driver finally put the transmission selector in REVERSE and the computer finally let off the throttle Shifting to neutral won't necessarily do anything in a smart system if it's already gone bonkers, and the computer is probably programmed to prevent going into neutral at highway speeds anyway. I suggest that all the fans of smart controls on cars watch 2001 to see why they are a bad idea. Peter ___ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Sudden Acceleration Revisited
I wonder how many of these things are people just trying to scam and get some money. You know there are going to be some scammers out there. Curt Raymond wrote: It sounds like the dude the other day was trying to hold speed with the brakes before they failed. So again, brake hard and hold until you win or crash... Most new cars have a computer controlled automatic trans so shifting in to neutral at 100mph with the throttle stuck would probably be an input the computer would ignore. Which is really the whole problem, the computer ignoring input from the driver I mean. -Curt -- Kaleb C. Striplin/Claremore, OK 95 E300, 92 500SEL, 92 300SD, 92 300E 4Matic, 91 350SDL, 91 300D, 89 560SEL, 87 300SDL x2, 85 380SE 5.0 Euro, 85 190D, 84 190D, 84 300D euro manny, 76 240D, 76 300D, http://www.okiebenz.com ___ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Sudden Acceleration Revisited
And they knew that in 1968. Peter Frederick wrote: In one case the driver finally put the transmission selector in REVERSE and the computer finally let off the throttle Shifting to neutral won't necessarily do anything in a smart system if it's already gone bonkers, and the computer is probably programmed to prevent going into neutral at highway speeds anyway. I suggest that all the fans of smart controls on cars watch 2001 to see why they are a bad idea. Peter ___ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com No virus found in this incoming message. Checked by AVG - www.avg.com Version: 9.0.733 / Virus Database: 271.1.1/2743 - Release Date: 03/13/10 01:33:00 -- Kaleb C. Striplin/Claremore, OK 95 E300, 92 500SEL, 92 300SD, 92 300E 4Matic, 91 350SDL, 91 300D, 89 560SEL, 87 300SDL x2, 85 380SE 5.0 Euro, 85 190D, 84 190D, 84 300D euro manny, 76 240D, 76 300D, http://www.okiebenz.com ___ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Sudden Acceleration Revisited
I wonder how much of the braking for the prius is base upon the regenerative system and how much is based on the REAL brakes... And when the real brakes are triggered vs the regenerative system. Also, with a prius, you have the gasoline engine and the electric motor to work with (against)... I wonder how a car with a keyless start system would respond to someone chucking the keyless fob out o the window while driving... You would think that the car should shut down since the authorization token was no longer present... -- John W Reames jwrea...@comcast.net Home: +14106646986 Mobile: +14437915905 On Mar 13, 2010, at 0:34, Jerry Herrman jer...@san.rr.com wrote: With your collective indulgence, I'd like to re-open the discussion of the topic sudden acceleration. You may recall in mid february I opened the discussion with this submission in vol. 51 issue 39, or thereabouts: ( So yesterday I heard what I believe was a public service announcement (by some automotive engineer, I think) on the radio saying that the least powerful brakes are going to easily overpower the most powerful engine.This suggests that applying your brakes firmly in an unexpected acceleration situation would prevent a catastrophe.) Responses from subscribers to this forum suggested that applying the brakes firmly and immediately to stop the car would be successful, regardless of the power output of the engine. Applying the brakes to merely slow down the vehicle, most concluded, would likely result in overheating the brakes to the point that they could be ineffective. The recent report of a Prius driver's scary struggle with sudden unexpected acceleration raises this topic again. I am taking no position on this issue. I am asking questions to better understand what is happening. Here are several questions that circulate through my mind. If a driver were to experience this phenomenon in a powerful car whose speed has gone well above 100 mph, would there be any hope of stopping the car using only the brakes? Can a Prius whose driver is trying to brake the car continue to accelerate? How powerful is the Prius engine? Can all cars be shifted easily into neutral in the event of this emergency? Is there any down side to turning off the engine in this situation? Having driven a 240D for many years, sudden acceleration sounded rather attractive . Now, not so much. Jerry 1982 240D 60+ horsepower __ Information from ESET Smart Security, version of virus signature database 4940 (20100312) __ The message was checked by ESET Smart Security. http://www.eset.com ___ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com ___ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Sudden Acceleration Revisited
*Nod* especially now with all the publicity. Date: Sat, 13 Mar 2010 09:09:47 -0600 From: Kaleb C. Striplin ka...@striplin.net To: Mercedes Discussion List mercedes@okiebenz.com Subject: Re: [MBZ] Sudden Acceleration Revisited Message-ID: 4b9baabb.9000...@striplin.net Content-Type: text/plain; charset=ISO-8859-1; format=flowed I wonder how many of these things are people just trying to scam and get some money. You know there are going to be some scammers out there. Curt Raymond wrote: It sounds like the dude the other day was trying to hold speed with the brakes before they failed. So again, brake hard and hold until you win or crash... Most new cars have a computer controlled automatic trans so shifting in to neutral at 100mph with the throttle stuck would probably be an input the computer would ignore. Which is really the whole problem, the computer ignoring input from the driver I mean. -Curt ___ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Sudden Acceleration Revisited
Scams are always a possibility, but I don't think all of them are. I've had a throttle fall open on me, fortunately in old Ford station wagon with a six cylinder -- the return spring popped off -- and that was alarming enough. I've also had the throttle stick on the old 72 280 SE, and I would suspect that you could NOT stop it from speed just by using the brakes -- I could barely hold it at about 1/8. Certainly, if you do not slow it way down at once, you will just burn out the pads, and once they and the rotors are red hot, you won't have much in the way of brakes at all. Note that in at least one run-away event on a Toyota, the driver DID fry out the brakes -- rotors were dark blue. Peter ___ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Sudden Acceleration Revisited
From: Jerry Herrman jer...@san.rr.com With your collective indulgence, I'd like to re-open the discussion of the topic sudden acceleration. You may recall in mid february I opened the discussion with this submission in vol. 51 issue 39, or thereabouts: ( So yesterday I heard what I believe was a public service announcement (by some automotive engineer, I think) on the radio saying that the least powerful brakes are going to easily overpower the most powerful engine.This suggests that applying your brakes firmly in an unexpected acceleration situation would prevent a catastrophe.) Responses from subscribers to this forum suggested that applying the brakes firmly and immediately to stop the car would be successful, regardless of the power output of the engine. Applying the brakes to merely slow down the vehicle, most concluded, would likely result in overheating the brakes to the point that they could be ineffective. The recent report of a Prius driver's scary struggle with sudden unexpected acceleration raises this topic again. I am taking no position on this issue. I am asking questions to better understand what is happening. Here are several questions that circulate through my mind. If a driver were to experience this phenomenon in a powerful car whose speed has gone well above 100 mph, would there be any hope of stopping the car using only the brakes? Can a Prius whose driver is trying to brake the car continue to accelerate? How powerful is the Prius engine? Can all cars be shifted easily into neutral in the event of this emergency? Is there any down side to turning off the engine in this situation? Having driven a 240D for many years, sudden acceleration sounded rather attractive . Now, not so much. Jerry 1982 240D 60+ horsepower -- During the 1980s I asked a trucker about the best way to use brakes on a long mountain grade with a heavy loaded pickup pulling a heavy trailer with no brakes. He said once you start down the grade apply the brakes gently and don't let off until the bottom of the hill. He said that the brake linings outgas, and when you let off and then reapply the brakes there is a layer of gas between the brake and the disc or shoe that severely reduces the efficient of the brakes. He also said that if you have to apply close to half braking force, you should then apply full force and stop on the side of road. You should let the brakes cool down for ten or fifteen minutes and then start down the hill in a lower gear with minimal braking pressure; never letting off the brake until the bottom of the hill. This would tell us that if a Prius engine ran away with itself, the driver should apply full braking pressure at the first hint of a runaway, never releasing full pressure, pull over, and never take his/her foot off the brake until he/she got the engine to stop. It's easy to tell people not to buy Toyotas, but there is already a large base of Toyotas on the road and many owners have no choice but to keep driving them. Yesterday I pulled up in the local Toyota dealers lot to see how his business was doing. There were salesmen doing deals in their cubicles with buyers, and others demonstrating various models to prospects. Business seemed to be pretty good Gerry Archer '83 300D and 240D ___ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Sudden Acceleration Revisited
archer wrote: During the 1980s I asked a trucker about the best way to use brakes on a long mountain grade with a heavy loaded pickup pulling a heavy trailer with no brakes. He said once you start down the grade apply the brakes gently and don't let off until the bottom of the hill. He said that the brake linings outgas, and when you let off and then reapply the brakes there is a layer of gas between the brake and the disc or shoe that severely reduces the efficient of the brakes. That's what was taught up till the early 90's. Then the recommendation changed to shorter applications of greater pressure and let off the pressure until needed again. He also said that if you have to apply close to half braking force, you should then apply full force and stop on the side of road. Agreed. You should let the brakes cool down for ten or fifteen minutes A car's brakes may cool off in that much time - but a big truck's probably won't. There is a _lot_ of steel in those drums! Another thing to keep in mind, there are _very_ few heavy trucks (class 7 and class 8) that have disk brakes - and not many cars have drum brakes. They two styles act different under heavy braking. And with air brakes, there's never any danger of the brake fluid boiling! This would tell us that if a Prius engine ran away with itself, the driver should apply full braking pressure at the first hint of a runaway, never releasing full pressure, pull over, and never take his/her foot off the brake until he/she got the engine to stop. I have often wondered about the practicality of using CO2 cylinders - like from paintball gear - and a butterfly valve in the intake of my automatic transmission diesel cars as a safety shutdown devices. It should work for all fuels, but not so well if the electric motor is running. Maybe for the electrics a mechanical shunt. Pull the lever and a spring loaded contactor shorts the motor power. Locks the motor and blows the fuse or semiconductor driving it. -- Philip ___ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
[MBZ] Sudden Acceleration Revisited
With your collective indulgence, I'd like to re-open the discussion of the topic sudden acceleration. You may recall in mid february I opened the discussion with this submission in vol. 51 issue 39, or thereabouts: ( So yesterday I heard what I believe was a public service announcement (by some automotive engineer, I think) on the radio saying that the least powerful brakes are going to easily overpower the most powerful engine.This suggests that applying your brakes firmly in an unexpected acceleration situation would prevent a catastrophe.) Responses from subscribers to this forum suggested that applying the brakes firmly and immediately to stop the car would be successful, regardless of the power output of the engine. Applying the brakes to merely slow down the vehicle, most concluded, would likely result in overheating the brakes to the point that they could be ineffective. The recent report of a Prius driver's scary struggle with sudden unexpected acceleration raises this topic again. I am taking no position on this issue. I am asking questions to better understand what is happening. Here are several questions that circulate through my mind. If a driver were to experience this phenomenon in a powerful car whose speed has gone well above 100 mph, would there be any hope of stopping the car using only the brakes? Can a Prius whose driver is trying to brake the car continue to accelerate? How powerful is the Prius engine? Can all cars be shifted easily into neutral in the event of this emergency? Is there any down side to turning off the engine in this situation? Having driven a 240D for many years, sudden acceleration sounded rather attractive . Now, not so much. Jerry 1982 240D 60+ horsepower __ Information from ESET Smart Security, version of virus signature database 4940 (20100312) __ The message was checked by ESET Smart Security. http://www.eset.com ___ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
