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Q&A Monday: The best way to smash automotive glass (mad physics) | Auto Expert John Cadogan

Q&A Monday: The best way to smash automotive glass (mad physics) | Auto Expert John Cadogan Save thousands on a brand new car (Australia only):

Spring-loaded centre punch:

The side and rear windows on your car are tempered - they've been heat treated by heating them up to about 620 degrees C, and then cooling rapidly, in a controlled way in air. This places the outer faces in compression and leaves the inside of the glass in tension.

It makes the glass tougher (mechanically and thermally) than normal glass but leaves it vulnerable to smashing into a billion pieces - and the best way to do that is with a spring-loaded centre punch (applied on the edges, where the glass is weaker - or at least where the stresses aren't as well resolved).

ALSO:
"You mentioned that performance driving enthusiasts often have a negative view of ESC but didn't get into that. It'd be great to hear some comments about what they think and why they think that." - Sharpie

A lot of performance drivers believe that ESC is the same as turning the fun off. As in - ESC stops you drifting, and otherwise hanging the tail out. Because, clearly, everyone needs to do that on the way home from work…

I’d suggest ESC is impossibly excellent, and even if you are Ken Block, driving a car on a public road with ESC represents the lesser of two potential evils. What ESC actually does is prevent thousands of people every year from sliding sideways and hitting a pole or a tree, or running wide into the oncoming traffic.

It’s just not much fun waking up in hospital with a profound, traumatic brain injury, and living for the next 30 years flat on a bed in a nursing home, with your intellect intact but unable otherwise to function. See, for me there’s no question that hell exists. People in that position are living in it right now.

"Why does that engine report in mg/stroke and not more useful units like grams/second or kilos/hour?" - Greg

OK - this relates to last week’s definitive ‘fuel consumption at idle’ test. Kilos per hour would be more useful to us, I guess, out here in Planet Beer Garden. But that MAF sensor data is produced for engineers working on engines. And mg/str (of air) is tremendously useful to know - because that’s how you program an injector. You tell it how many milligrams per stroke is required for a range of different engine operating conditions, like engine speed and throttle position.

If the ECU reported kilos per hour, they’d need to convert it back to mg/str to do their mad fuel map-tweaking voodoo.

"Look where you want to go". Wow, that's channeling some serious Keith Code advice, and probably something that almost everyone overlooks as they become "target fixated" on what they don't want to hit (but almost always do). - Marlboro-man Matt

Target fixation is a serious problem in a driving emergency. Because if you look at the problem: the kid in the middle of the road, the kangaroo in the middle of the road, the grille of the semi-trailer that has strayed onto your side of the road, that tree you’re drifting towards at the side of the road… you’re probably gunna hit.

And that’s like asking to spend the rest of your life in that living hell we discussed earlier … if there’s an afterwards.

Target fixation is why people who see potholes still hit them: Because they’re looking at them. Gotta look for the gap. Easy to say; hard to do. Especially in an emergency, where perception is a knife fight in a phone box. (This is why people who have played contact sports as a kid generally do better at this - they already have this app installed ‘upstairs.’)

On driving emergencies, especially, but also at all other times, you have to train yourself to look for the solution and not at the problem.

“I recently bought a Nissan Navara NP300. The chassis is bent. I called and spoke to Nissan. They basically said they will probably deny the claim, as i've got it raised 40mm. I put a claim through insurance because i'll get no movement from Nissan, according to the team here. I believe this vehicle is not suitable off the bitumen and I'm concerned I'll be left with a lemon. AAMI have employed an engineer to investigate, but feel ill be left with a broken car that Nissan won't take back. Can you provide any assistance or guide me to get this sorted??” - Chris

I’m tipping the chassis didn’t just randomly wake up bent, perhaps last Tuesday morning. Some event probably occurred that bent it, because that’s how this works. It would have been nice to know what - and it worries me that this critical fact has been left out of the narrative here.

In any case, modifying the car in some significant way does open the door to the carmaker denying a warranty claim, and then if you disagree with their assessment you need to fight, using lawyers and consultant experts, and that’s expensive.

If the insurance company is processing a claim, what’s the point fighting?

Cadogan

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