Every BMW 3-Series Has 2,500 HP... In Its Brakes

[Kowalski]

Is there any automotive engineer in the GCF to prove whether this can be true or just pure marketing bullshit?

In response to Toyota's unintended acceleration debacle, BMW engineers decided to calculate the equivalent horsepower of a 3-series' brakes: roughly 2,500 HP. That's right, every 3-Series ships with more than twice the power of a Bugatti Veyron.

The engineers arrived at the 2,500 HP number after measuring the car's 60-0 MPH deceleration time (2.5 seconds), then calculating how much horsepower would be required to achieved equivalent acceleration (0-60 MPH in 2.5 seconds). This is obviously an over-simplified number that exists merely in the calculations on an engineer's note pad - the rear-wheel drive 3-series would need extensive modifications to transfer that accelerative power then send it to the ground - but it does demonstrate exactly how much more powerful the brakes are over the engine, which, in the case of this Bimmer, makes between 200 and 300 HP.

What's this mean for unintended acceleration? Even if you couldn't shift the car into neutral, even if the throttle was stuck wide open, even if you couldn't turn the engine off, you could still stop the car by using the brakes, which can easily overpower the engine.

Think this only applies to expensive cars from Germany and not cheap cars from Japan? The 2010 Toyota Prius's 60-to-0 time is only a couple hundredths of a second off the BMW's figure, still giving it huge equivalent horsepower numbers from its brakes.

Why are BMW engineers crunching numbers in response to a Toyota problem? They're likely just as convinced as we are that the entire situation is caused by human error and, because of that, it could effect them too. In response to the threat of enormous lawsuits, they're quietly building a stockpile of evidence so they can conduct a sort of legal blitzkrieg against any potential aggressors.

Source: Every BMW 3-Series Has 2,500 HP... In Its Brakes - Toyota Recall - Jalopnik

 

[LaArtist]

In theory this might hold..but its not so significant..as all cars have a huge brake output compared to the engine..
The right calculation would be.. the weight of the car, the speed and the time it takes to stop.. to calculate the needed force to halt the car..

 

[batosai]

"That's right, every 3-Series ships with more than twice the power of a Bugatti Veyron"

That makes the Veyron ships with the braking power of a nuclear warhead, then.

 

[Monster]

Can someone dig up my old post? I did a calculation to find the energy generated from the brakes on a GTR and a ZR-1, it was a while ago and the search function doesn't seem to be giving me what I want.

 

[NarutoRamen]

That's a pretty dumb calculation and serves no purpose.

 

[Sayyaaf]

OK , while attending the Porsche road show, porsche engineers had a small quiz where he questioned the audience what is real power required to stop a car. Most of answers were "at least twice the power of the engine" which sounded resoanable, however the answer came as a shock to every one. Porsche ,which supplies one of the best stock brakes in the auto industry, have their own standard which is at least 3 times the power of the engine. The car on demonstration was the 911 4S which is roughly 400 Bhp (385 to be exact), the car had braking power of almost 1200 - 1300 BHP.

So 2500 HP braking power is really exaggrated.

One more heads up guys, when you hit the brakes for a complete stop (In case of emergency), You should press the pedal at least at a power equal to (or more) than 70Kg of weight. That's what the instructer told us and it holds for almost all cars.

 

[Deleted member 25]

Humm really with Today's electronic brake emergency systems ? 70 kg seems quite a lot to me.

 

[Beemer B773ER]

...ooooh, so that's what they mean by brake horsepower (bhp).

For me, the most interesting part of that article is this paragraph:

Why are BMW engineers crunching numbers in response to a Toyota problem? They're likely just as convinced as we are that the entire situation is caused by human error and, because of that, it could effect them too. In response to the threat of enormous lawsuits, they're quietly building a stockpile of evidence so they can conduct a sort of legal blitzkrieg against any potential aggressors.

Fascinating that they view it as mostly human error as well.

 

[Centurion]

Ironically I watched the making of the Veyron by National Geographic and they said that the Veyron's brakes generate 4,000hp to stop the car.