M3 burns after revving competition

Spliffcat said:
Why when tootling along in a Gt3 does one always get a dick in a M3 reving his little engine.
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GT3 engine = 3.8l, 6 cylinders
V8 M3 = 4.0l, 8 cylinders. Little?
Also, your car isn't much better at not bursting into flames... ;)

810050d1393352340-top-gear-tg1.jpg

810052d1393352340-top-gear-tg2.1.jpg
 
Sinbad said:
Still find it unlikely that just revving will cause the exhaust to get that hot. The load on the engine is actually very low when you do that, so there will not be a large amount of exhaust gas produced, especially compared to running at full throttle.
More likely there was a legitimate engine failure caused by the revving abuse (high vacuum in the cylinders caused by high RPM with low throttle opening) that punched a hole in the block, spilling oil onto the exhaust.
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It is not the load that matters. It is a simple fact of no cooling. A car at idle gets hotter than a car that is full speed, because cooling increases exponentially with speed .By revving the car you increase the "work rate" along with fiction both of which adds more heat into the system with. And if you do not take that heat away fast enough it is only a matter of time before it bursts into flames.
 
ngwe23 said:
It is not the load that matters. It is a simple fact of no cooling. A car at idle gets hotter than a car that is full speed, because cooling increases exponentially with speed .By revving the car you increase the "work rate" along with fiction both of which adds more heat into the system with. And if you do not take that heat away fast enough it is only a matter of time before it bursts into flames.
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Nope. Car has a radiator fan :p
 
Sinbad said:
Nope. Car has a radiator fan :p
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The radiator fan will keep the engine cool, but doesn't affect the temperature of the exhaust.

I was at Kyalami a few years back where a guy parked his new Alfa with a very hot catalytic converter on the grass in one of the parking areas - it set the grass alight and torched about 30 cars.

Cats get up to ridiculously high temperatures ( 3500 C IIRC) and if the car is not moving and having some cooling air running past it, you will have a problem.
 
Fazda said:
The radiator fan will keep the engine cool, but doesn't affect the temperature of the exhaust.

I was at Kyalami a few years back where a guy parked his new Alfa with a very hot catalytic converter on the grass in one of the parking areas - it set the grass alight and torched about 30 cars.

Cats get up to ridiculously high temperatures ( 3500 C IIRC) and if the car is not moving and having some cooling air running past it, you will have a problem.
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Yeah know fully understood, but I don't think the cat's going to get to that temperature without load on the engine? ie - revvving it in neutral...?
Looking at the video, the fire didn't start at the cat anyway. Was too far back for that
 
Sinbad said:
Yeah know fully understood, but I don't think the cat's going to get to that temperature without load on the engine? ie - revvving it in neutral...?
Looking at the video, the fire didn't start at the cat anyway. Was too far back for that
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It could have been as simple as the guy having ridden over a Checkers bag in the road, that then hooked on to the exhaust - any piece of rubbish could have started the fire if it wasn't the cat.
 
Fazda said:
It could have been as simple as the guy having ridden over a Checkers bag in the road, that then hooked on to the exhaust - any piece of rubbish could have started the fire if it wasn't the cat.
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Yeah, that's more likely I think.
 
LOL - I see that I got my temperature spectacularly wrong!! :o

Catalytic converters...
• Are a chemical reactor that use chemical reactions to theoretically change toxic emissions into less harmful emissions
• DO NOT begin to work until their temperature exceeds 290°C (550°F)
• MUST reach their optimum operating temperature of 430°C (806°F) needed to reduce toxic emissions
• Substantially increase toxic emissions for the first 15 minutes from a cold start until they reach 430°C (806°F)
• MUST have the exhaust gases that exit the engine alternate rapidly between high CO and O2 gases to reduce toxic emissions. This requires the vehicles computer to precisely alternate the fuel mixture slightly richer and leaner from 14.7. If the computer does not do this properly it substantially increases toxic emissions
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Still bloody hot, however!! :p
 
Sinbad said:
Nope. Car has a radiator fan :p
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Dont know if you are serious or being sarcastic, there are some components that cannot adequately be cooled by a fan esp if you are revving the thing. The fan is designed to oake care of the cooling needs at idle.
 
ngwe23 said:
Dont know if you are serious or being sarcastic, there are some components that cannot adequately be cooled by a fan esp if you are revving the thing. The fan is designed to oake care of the cooling needs at idle.
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I'm being serious, but don't worry about it...
 
Video deleted, I wonder if it's the owners who managed to contact the uploader and threaten with legal action, in a day that video racked up +9000 views last I checked.

Knew I should've downloaded it with JetVD. -_-
 
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