FridgeFreezer Posted January 27, 2010 Share Posted January 27, 2010 Seems after recalling 4.2 million cars they still got it wrong and have to recall another 2.4 million at least LR's only break down rather than actively trying to kill you http://news.bbc.co.uk/1/hi/business/8482366.stm Most worrying is that the brakes don't seem to be up to stopping them, which would seem to be something of an oversight. Quote Link to comment Share on other sites More sharing options...
Aragorn Posted January 27, 2010 Share Posted January 27, 2010 I doubt many cars brakes would be up to stopping the car if the throttle was jammed open... Its surely just a case of knocking it out of gear or in the worst case, turning the ignition off though... Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted January 27, 2010 Author Share Posted January 27, 2010 I thought it was a fundamental point of vehicle design that the engine couldn't overcome the brakes Also seems the clever electronics don't allow you to do things like shift the (auto) box into neutral or apply the (electric) handbrake when you're doing 90. Been quite a lot of coverage on Risks digest, an experienced police driver & family were killed after trying just about everything to make the thing stop. Quote Link to comment Share on other sites More sharing options...
tweetyduck Posted January 27, 2010 Share Posted January 27, 2010 In the UK we have a thing called a clutch so no issue. It happend to me the other week in the 110. Automatic and you're nearly screwed due to the electronics that prevent you switchin gof the engine and stuff mentioned here. Quote Link to comment Share on other sites More sharing options...
GBMUD Posted January 27, 2010 Share Posted January 27, 2010 In the UK we have a thing called a clutch so no issue. You might. If my car will do 0-60 in say, 10 seconds but I can do 60-0 in more like 3 seconds, surely the brakes will overcome the engine? I might try it tomorrow. Chris Quote Link to comment Share on other sites More sharing options...
Rich_P Posted January 27, 2010 Share Posted January 27, 2010 I guess this is one of the joys of electronics - when they go wrong they can really go wrong. Quote Link to comment Share on other sites More sharing options...
Aragorn Posted January 27, 2010 Share Posted January 27, 2010 I still cant see why you couldnt just turn the ignition off? It would be completely crazy to design a car where the ignition couldnt be turned off on demand?! Was a guy couple years ago who claimed his throttle was "stuck" in his BMW in the UK, and drove for miles down some motorway, before finally stacking it into a roundabout. He cooked the brakes trying to slow the car and for some retarded reason didnt turn the ignition off or knock the transmission into neutral. http://www.timesonline.co.uk/tol/news/article739808.ece The police charged him but i dunno if he was convicted: http://www.theregister.co.uk/2006/06/20/bmw_driver_arrest/ Quote Link to comment Share on other sites More sharing options...
Turbocharger Posted January 27, 2010 Share Posted January 27, 2010 I expect the brakes can stop the car, under full power, once. I've just finished bedding some new pads in and they do exceed the engine power in my MG, even in first gear. However, if the panicked housewife at the wheel spends ten miles holding her speed down to a steady 50mph and THEN tries to stop, she might find that the brakes have stopped being able to dissipate heat any more - they're smoking strongly and badly faded, the smell's terrifying and NOW they won't stop her Jap SUV. That's my take on the whole thing. It's a bad day in the design office when you make an announcement that knocks 5% off a global company's share price though... Quote Link to comment Share on other sites More sharing options...
landmannnn Posted January 27, 2010 Share Posted January 27, 2010 I expect the brakes can stop the car, under full power, once. I've just finished bedding some new pads in and they do exceed the engine power in my MG, even in first gear. However, if the panicked housewife at the wheel spends ten miles holding her speed down to a steady 50mph and THEN tries to stop, she might find that the brakes have stopped being able to dissipate heat any more - they're smoking strongly and badly faded, the smell's terrifying and NOW they won't stop her Jap SUV. That's my take on the whole thing. It's a bad day in the design office when you make an announcement that knocks 5% off a global company's share price though... A 4 to 6 litre V8 coupled to an autobox and torque converter will be very hard to stop, don't forget no vacuum for the servo with wide open throttle either. Quote Link to comment Share on other sites More sharing options...
DSN Posted January 28, 2010 Share Posted January 28, 2010 Some people now design it so that if you hit the brake and throttle together, the brake is master and it cuts engine power (so no more left foot braking!). I guess that was not the case here. Quote Link to comment Share on other sites More sharing options...
tel Posted January 28, 2010 Share Posted January 28, 2010 Some people now design it so that if you hit the brake and throttle together, the brake is master and it cuts engine power (so no more left foot braking!). I guess that was not the case here. my audi had that feature was a right pig when trying to bed new pads in Quote Link to comment Share on other sites More sharing options...
Eightpot Posted January 28, 2010 Share Posted January 28, 2010 Freelanders have that interesting feature - I spent weeks trying to figure out why the engine wouldn't rev then discovered a broken brake pedal switch was the culprit. Quote Link to comment Share on other sites More sharing options...
HoggyN Posted January 28, 2010 Share Posted January 28, 2010 I've had the throttle stick open on me a couple of times. Both times I turned off the ignition to kill the engine. However, there was a time delay from WTF?!!! to turning the key. I was lucky that I wasn't in a situation where the time delay mattered. I also remember a similar situation where I set off from my house, approached the T junction at the end of the road only to find an invisible force preventing my right foot moving from the throttle to the brake. I ended up stamping on the brake with my left foot but still stopped a few feet over the line with my arseh*le fluttering from half-a-crown to sixpence. Turned out I'd trapped my shoelace in the door when I got in. Quote Link to comment Share on other sites More sharing options...
tweetyduck Posted January 28, 2010 Share Posted January 28, 2010 Turned out I'd trapped my shoelace in the door when I got in. Quick thinking. I've had something similar except i managed to free the correct foot. Not sure I’d be a cool as you but you never know. The other week the accelerator peddle got stuck under the mat approaching the roundabout at the end of the road. It clutched with the left and lifted the accelerator with my right toe freeing it from the mat. Got out my Swiss army knife and rectified the mat in seconds and lobbed the piece in the back. Toyota should just issue Swiss army knifes. Quote Link to comment Share on other sites More sharing options...
pat_pending Posted January 28, 2010 Share Posted January 28, 2010 If you worked for a modern car dealership like I do, you'd wonder why anyone buys a new car. The manufacturers supposedly spend millons on development only to have the things fall apart on the customers. And I work for one of the better makes, reliability wise anyway. Poor design, cheaply made, simulated testing that realy doesn't replicate real world use, no matter what they tell you. The only way they can stay in business is by selling huge numbers of cars, buy a new car every year, throw away the old one. For this to work there has to be a constant change in the look of the car, the gadgets it has, the power, mpg, even the colours and the pattern on the trim, all done to make you think your car is out of date before it's 5 minutes old. There was a time when a company like Lucas could make an ignition coil that would fit 75% of the vehicles in the uk going back 20 years or more, this allowed development and investment in a product with a long design life. Now it would be a "module" that may only fit one model of one manufacurer and may be obsolete after a few years, needs to be produced quickly and cheaply, probably in the far east. This makes for unreliable componants. The ammount of recalls for defective parts has gone through the roof in recent years, fortunately few are as potentialy dangerous as this one. Quote Link to comment Share on other sites More sharing options...
Fatboy Posted January 29, 2010 Share Posted January 29, 2010 I had the throttle jam wide open on a V8 SD1 Vitesse a few years ago when I was approaching a T junction. I pushed the brake pedal with all of my strength, the front wheels locked up but the back ones were spinning like a staging dragster... The noise and smoke off the tyres was incredible! Fortunately, the cable / pedal freed itself before I created a new exit at the junction.. Unfortunately, I didn't think about simply turning the engine off or putting the box into neutral.. or even turning the wheel and doing doughnuts until it ran out of fuel Quote Link to comment Share on other sites More sharing options...
TheRecklessEngineer Posted January 29, 2010 Share Posted January 29, 2010 I have an '02 Volvo V40 with very nearly 170k on the clock. Just passed the MOT with flying colours. How's that for reliability of a 'new' car? Quote Link to comment Share on other sites More sharing options...
Andrew Chua Posted January 29, 2010 Share Posted January 29, 2010 that is why the pedals on a land rover require quite a bit of strength to hold on. yes, the aching right foot after a 300km highway run. ha ha. besides them behind so high, they couldn't really get wedged on the mat either. Quote Link to comment Share on other sites More sharing options...
BogMonster Posted January 29, 2010 Share Posted January 29, 2010 If you worked for a modern car dealership like I do, you'd wonder why anyone buys a new car. +1 Quote Link to comment Share on other sites More sharing options...
jules Posted January 29, 2010 Share Posted January 29, 2010 Freelanders have that interesting feature - I spent weeks trying to figure out why the engine wouldn't rev then discovered a broken brake pedal switch was the culprit. A mate was teaching me to left foot brake the racing freelander and it worked perfectly in his works shogun but I couldn't get the hang of it as I just lost all power I couldn't work it out until we found that if the brakes are applied the revs cut to tick over. The TMC doesn't suffer from that problem Quote Link to comment Share on other sites More sharing options...
miketomcat Posted January 29, 2010 Share Posted January 29, 2010 interestingly if you apply the hand brake on tdv8 Range rover or the sport at 70mph you stop as quickly as you do if you stamp on the brakes and yes i have tried it mind i didn't try it with my foot still on the trottle my brain wouldn't allow that. mike Quote Link to comment Share on other sites More sharing options...
mad_pete Posted January 29, 2010 Share Posted January 29, 2010 If my car will do 0-60 in say, 10 seconds but I can do 60-0 in more like 3 seconds, surely the brakes will overcome the engine? I might try it tomorrow. Hmm let me attack the issue with bad science Engine 150 BHP. Lets put lose 20% in the drive train. 120 BHP power at the wheels, lets swap to Kw 120 BHP = 88 Kw Brakes convert motion to heat and energy is conserved so at full engine power each brake has to dissipate 22 KW of heat and that's just to stop the car accelerating. At 60 mph a 1.5 ton car has 530 KJ of kinetic energy that has to be dissipated on top of the extra power the engine is adding in. Air resistance is chipping in with about 278 N of drag say. So power of that is ( force x speed ) 278 x 27 = 7.5 KW not that much So each brake needs to be able to dissipate about 25 KW of heat If I take this If my car will do 0-60 in say, 10 seconds but I can do 60-0 in more like 3 seconds Brakes are roughly 3 times more powerful than the engine so 264 KW. So you should be able to overpower the engine and stop in 4 secs at full brake power but if you only manage half power on the brakes I think you'd be looking at overheat and brake fade very quickly. So overall I'd say yes brakes can overpower the engine but you need to be quick. Quote Link to comment Share on other sites More sharing options...
timmymac Posted January 29, 2010 Share Posted January 29, 2010 a very good point backed by maths but i used to drive a mini and id say that the brakes had trouble over powering the engine even in netural But on a serious note as safety standard surely a car should be designed to stop in this situation ? Quote Link to comment Share on other sites More sharing options...
mad_pete Posted January 29, 2010 Share Posted January 29, 2010 hehe I wouldn't trust my maths Quote Link to comment Share on other sites More sharing options...
will4x4 Posted January 30, 2010 Share Posted January 30, 2010 Good maths... i know its been said but yes brakes have to over power a car even at full engine revs - i try it on ever company car i drive Quote Link to comment Share on other sites More sharing options...
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