Not Malicool.

Sold!

Obviously the only thing I was astonished about was how long it took you.

You must be looking forward to your new 12.9 inch iPad Pro and one of those ace smart keyboard things and a swizzy iPad pen. Very kind of Gazchap to do that.

Trying to decide whether to get this new BMW remapped. DMS Automotive are the go-to guys for this kinda thing, and their remap takes it from 258bhp to 331, and 418lb/ft to 482...

Yes.

Jesus that's a significant increase!

Fairly sure the Rover can take it.

Should it matter? Surely a set of brakes takes X distance to stop a car going at 40mph, regardless of how many bhp got it there? Or is the assumption that more bhp means you're just going to be going faster.

Momentum isn't a function of time.

If I have one 1500kg body travelling at a steady speed of 70mph, and another 1500kg body that's accelerating very rapidly but whose instantaneous speed was also 70mph at the precise moment brakes were applied, which do you think will require the greater braking force?

I get in trouble doing this, but assuming the acceleration is no longer being applied, surely the answer is that they require identical braking force?

John McDonnell

The car's got shit tons of momentum, sure - but I'm saying that a car that's just accelerated to 70 and a car that's been at 70 for the last five miles have identical momentum.

f does equal ma indeed, so the second you're no longer supplying engine power, the f is zero and a is also zero, no?

But that's the point. You were (microseconds before) applying (significantly boosted) engine power, so 'a' is still happening. Stop thinking in static speed terms.

Well, with much more power, you're inevitably going to be presenting your brakes with faster rates of acceleration than otherwise would be the case, when they're applied (and therefore more likely to be applied more sharply than they would've hitherto been, so it's a bit of a double whammy, really). It's not about static, steady speeds motorway-style; the reality is a far more dynamic accelerative/decelerative picture.

Physics innit.

You must be looking forward to your new 12.9 inch iPad Pro and one of those ace smart keyboard things and a swizzy iPad pen. Very kind of Gazchap to do that.

I'm fairly sure that I said I wanted sex every day for the next 20 years if he gets a BMW but I think he's forgotten that....

I'm fairly sure that I said I wanted sex every day for the next 20 years if he gets a BMW but I think he's forgotten that....

How is that a deterrent?

Guys, guys. I ain't no physics teacher. If you don't believe me, why do you suppose that a 155mph limited BMW M3 has much better brakes than an equally 155mph speed limited BMW 330i or whatever? They both do the same top speed and they both weigh the same, so why bother? And why do people always say upgrade brakes with any remap such as this?

I've tried to give examples like the bullet etc. but I can't think of any other way to explain it so I give up, as I have homemade gnocchi waiting.

Okay, consider a rifle bullet that weighs 10g that's been fired (the force is removed), say one hundreth of a second after it's been fired. It's travelling, say, at only 5mph, but it's accelerating like fuck.

Surely bullets are slowing down as soon as they leave the barrel. How can something keep accelerating once the acceleration force is no longer being applied?

Interesting bullet fact that's pretty obvious but a not a lot of people think through - it you shoot a bullet from a gun in a straight line (ie, not upward) and drop a bullet from your hand when you pull the trigger, they'll both hit the ground at the same time.