Caught doing 120mph on the motorway

[ZX10R NIN]

anonymous said:

[redacted]

As in not loosing the car as the ESP linked to the ABS

Not just carbon ceramics my CLK 63/SL55 have 8 Pots upfront 4 pots on the rear & stopped within a foot of the carbon ceramic CL65

[jmorgan]

Can you get carbon sticky on lookalike for my steel discs so it will look like it will stop?

[ZX10R NIN]

youngsyr said:

No, what I'm saying is that you're talking out of your backside when you say a road legal car can stop from 140 mph in 100 yards.

And, for what it's worth, some "braking" aids actually increase the stopping distance, e.g. ABS.

Others are marketed as improving braking, but have almost no impact at all on stopping distance, unless you're doing repeated extremely heavy braking, e.g. Ceramic brake discs.

I was in the car we were coming up to the 100 yard marker & had to stop, as I said it was sketchy but we stopped before the line

[The Mad Monk]

youngsyr said:

Let's put it another way:

At 120 mph your stopping distance is something like 885 feet / 270 metres.

At 70 mph your stopping distance is something like 388 feet / 118 metres.

The difference between them is over 1.5 football pitch lengths.

If you can't tell whether you're going to need 270 metres to stop or 118 metres to stop, you shouldn't be on the road.

Sources:

http://www.csgnetwork.com/stopdistcalc.html
http://www.csgnetwork.com/stopdistinfo.html

"The difference between them is over 1.5 football pitch lengths".

Is that Association Football, Rugby Union football, Rugby League Football, Australian Rules Football, Gaelic Football, American Football, or something else?

[youngsyr]

ZX10R NIN said:

anonymous said:

[redacted]

As in not loosing the car as the ESP linked to the ABS

Not just carbon ceramics my CLK 63/SL55 have 8 Pots upfront 4 pots on the rear & stopped within a foot of the carbon ceramic CL65

ESP and ABS are designed to allow you to maneuver whilst braking, not reduce straight-line braking distsance.

The carbon brakes on the CL65 AMG look impressive, but this review here says they're no better than the standard CL600 brakes, 1min 12s onwards:

https://www.youtube.com/watch?v=mBIEWE9d8O4

Not surprising as the advantage of carbon ceramic brakes is primarily heat reduction, not reducing stopping distance.

[AW111]

ZX10R NIN said:

GT3 & M3 took 4.26/4.81 seconds to stop from 100mph this includes the reaction times, a football pitch is between 90m-120m in length, the above figure of 53 metres is well short of a pitch.

Unless I've mis understood the maths.

The times don't really include reaction time, because the driver is cued up for a panic stop, but anyway...

Assuming 0 reaction time involved (best case)

Speed = 44.44 m/s
Time = 4.26 s
A = 10.43 m/s ^2 (1.06 g)

Distance : 94.7 m

If the quoted time is reaction time + braking time, ie 0.5s reaction followed by 3.76s of braking, the distance is 106 m

[TheAllSeeingPie]

AW111 said:

ZX10R NIN said:

GT3 & M3 took 4.26/4.81 seconds to stop from 100mph this includes the reaction times, a football pitch is between 90m-120m in length, the above figure of 53 metres is well short of a pitch.

Unless I've mis understood the maths.

The times don't really include reaction time, because the driver is cued up for a panic stop, but anyway...

Assuming 0 reaction time involved (best case)

Speed = 44.44 m/s
Time = 4.26 s
A = 10.43 m/s ^2 (1.06 g)

Distance : 94.7 m

If the quoted time is reaction time + braking time, ie 0.5s reaction followed by 3.76s of braking, the distance is 106 m

So basically a heavier car (CL65 is around 2100kg compared to GT3 which is 1400ish and M3 which is 1550-1600) doing 40mph extra is likely to have stopped in 100m? Didn't think so.

[TOYNEG]

all this is why i love going to Germany - where you can just go as fast as you like when the road and conditions allow

[tapereel]

TOYNEG said:

all this is why i love going to Germany - where you can just go as fast as you like when the road and conditions allow

I'm figuring this stopped really quickly on the autobahn:

[TOYNEG]

tapereel said:

TOYNEG said:

all this is why i love going to Germany - where you can just go as fast as you like when the road and conditions allow

I'm figuring this stopped really quickly on the autobahn:

wow yeah i reckon it did!

[MikeGoodwin]

I honestly do not know of another forum that descends into this sort of in depth madness involving technical and mathematical equations to determine a topic somewhat irrelevant to the topic set out by the OP.

Bravo.

[GreatGranny]

MikeGoodwin said:

I honestly do not know of another forum that descends into this sort of in depth madness involving technical and mathematical equations to determine a topic somewhat irrelevant to the topic set out by the OP.

Bravo.

Utterly pointless.

Its descended into something that's very st indeed.

PH at its not so finest.

[iphonedyou]

How st is this thread!?

[redjohn]

ZX10R NIN said:

anonymous said:

[redacted]

As in not loosing the car as the ESP linked to the ABS

Not just carbon ceramics my CLK 63/SL55 have 8 Pots upfront 4 pots on the rear & stopped within a foot of the carbon ceramic CL65

The limiting factor* in braking is the grip available between the tyre and road. Providing your brakes can exert a force that is greater than this limit of grip it doesn't matter how many pots you have or whether they are steel, ceramic or bubble gum. The brakes from any half decent modern car exceed the limit of grip between road tyres and the pubic highway. Compensating for tyres your CLK63 won't stop any quicker. Fancy brakes bring repeatability - the ability to stop from big speeds in quick succession and help with the "feel" of braking both of which aren't applicable in an emergency stop on a public road.

• in rl the limiting factor is the nut behind the wheel either not braking or not braking hard enough.

Edited by redjohn on Friday 10th July 18:13

[Magic919]

It's braking, BTW.

[Devil2575]

I've also read that most people don't tend to actually brake hard enough anyway so going on distances from tests with drivers who really know what they are doing is not very representative.

[Pete317]

Or you could read the road properly so you seldom if ever need to perform an emergency stop - but always be prepared to do so.

[jmorgan]

Pete317 said:

Or you could read the road properly so you seldom if ever need to perform an emergency stop - but always be prepared to do so.

But I like traffic waves.

[Pete317]

jmorgan said:

Pete317 said:

Or you could read the road properly so you seldom if ever need to perform an emergency stop - but always be prepared to do so.

But I like traffic waves.

Ok then, I'll wave the next time I see you

[Devil2575]

MikeGoodwin said:

I honestly do not know of another forum that descends into this sort of in depth madness involving technical and mathematical equations to determine a topic somewhat irrelevant to the topic set out by the OP.

Bravo.

It is epic isn't it