Discussion
Ever thrown the anchors out big style while wearing a hoodie? I was having a bit of a play this morning and stood on the stop pedal from considerable velocity. The laces from my hoodie came forward and were parallel with my eyes... Never known a car that could do that under stopping 
It was so much fun I tried it again, it definitely works. God I love Porsche brakes!
It was so much fun I tried it again, it definitely works. God I love Porsche brakes!
BliarOut said:
Ever thrown the anchors out big style while wearing a hoodie? I was having a bit of a play this morning and stood on the stop pedal from considerable velocity. The laces from my hoodie came forward and were parallel with my eyes... Never known a car that could do that under stopping
It was so much fun I tried it again, it definitely works. God I love Porsche brakes!
It was so much fun I tried it again, it definitely works. God I love Porsche brakes!
Just to be a boring science person, most cars are capable of the same braking g - its the tyre/road interface that is the limiting factor for braking g. If you look at most detailed car tests, braking times and distances are very, very similar for most performance cars...
johnfm said:
BliarOut said:
Ever thrown the anchors out big style while wearing a hoodie? I was having a bit of a play this morning and stood on the stop pedal from considerable velocity. The laces from my hoodie came forward and were parallel with my eyes... Never known a car that could do that under stopping
It was so much fun I tried it again, it definitely works. God I love Porsche brakes!
It was so much fun I tried it again, it definitely works. God I love Porsche brakes!
Just to be a boring science person, most cars are capable of the same braking g - its the tyre/road interface that is the limiting factor for braking g. If you look at most detailed car tests, braking times and distances are very, very similar for most performance cars...
Very true. Whilst I was doing work exp. at Autocar, I was filling in a couple of spec sheets, and the Lotus Europa S and podgy Mercedes R class had remarkable similar braking times from 60. I think they were separated by the slightest sliver of a margin one tenth of a second in size.
identti said:
johnfm said:
BliarOut said:
Ever thrown the anchors out big style while wearing a hoodie? I was having a bit of a play this morning and stood on the stop pedal from considerable velocity. The laces from my hoodie came forward and were parallel with my eyes... Never known a car that could do that under stopping
It was so much fun I tried it again, it definitely works. God I love Porsche brakes!
It was so much fun I tried it again, it definitely works. God I love Porsche brakes!
Just to be a boring science person, most cars are capable of the same braking g - its the tyre/road interface that is the limiting factor for braking g. If you look at most detailed car tests, braking times and distances are very, very similar for most performance cars...
Very true. Whilst I was doing work exp. at Autocar, I was filling in a couple of spec sheets, and the Lotus Europa S and podgy Mercedes R class had remarkable similar braking times from 60. I think they were separated by the slightest sliver of a margin one tenth of a second in size.
BliarOut said:
identti said:
johnfm said:
BliarOut said:
Ever thrown the anchors out big style while wearing a hoodie? I was having a bit of a play this morning and stood on the stop pedal from considerable velocity. The laces from my hoodie came forward and were parallel with my eyes... Never known a car that could do that under stopping
It was so much fun I tried it again, it definitely works. God I love Porsche brakes!
It was so much fun I tried it again, it definitely works. God I love Porsche brakes!
Just to be a boring science person, most cars are capable of the same braking g - its the tyre/road interface that is the limiting factor for braking g. If you look at most detailed car tests, braking times and distances are very, very similar for most performance cars...
Very true. Whilst I was doing work exp. at Autocar, I was filling in a couple of spec sheets, and the Lotus Europa S and podgy Mercedes R class had remarkable similar braking times from 60. I think they were separated by the slightest sliver of a margin one tenth of a second in size.
I doubt thay've got the same size contact patches though
sleep envy said:
BliarOut said:
identti said:
johnfm said:
BliarOut said:
Ever thrown the anchors out big style while wearing a hoodie? I was having a bit of a play this morning and stood on the stop pedal from considerable velocity. The laces from my hoodie came forward and were parallel with my eyes... Never known a car that could do that under stopping
It was so much fun I tried it again, it definitely works. God I love Porsche brakes!
It was so much fun I tried it again, it definitely works. God I love Porsche brakes!
Just to be a boring science person, most cars are capable of the same braking g - its the tyre/road interface that is the limiting factor for braking g. If you look at most detailed car tests, braking times and distances are very, very similar for most performance cars...
Very true. Whilst I was doing work exp. at Autocar, I was filling in a couple of spec sheets, and the Lotus Europa S and podgy Mercedes R class had remarkable similar braking times from 60. I think they were separated by the slightest sliver of a margin one tenth of a second in size.
I doubt they've got the same size contact patches though
johnfm said:
Just to be a boring science person, most cars are capable of the same braking g - its the tyre/road interface that is the limiting factor for braking g. If you look at most detailed car tests, braking times and distances are very, very similar for most performance cars...
I don't doubt you, but if this is the case, then what's the point of upgrading brakes? Oli.
Sorry guys - you are mistaking 'conventional wisdom' for 'cold, hard science'. In terms of stopping distance, -1g is pretty achievable by most cars. Contact patch has very little to do with it, as the retarding force acting at the tyre/road interface is a function of the coefficient of friction and the normal load. THe load is independent of contact area (this merely alters the pressure exerted by the the tyre on the road). Tyre compound and road surface are greatest influence. Though you would think that car mass would be really important too (as the kinetic energy of the vehicle is directly proportional to it), but a lighter car exerts less normal load onto the tyre - so less available grip.
Where Porsche brakes shine is repeated braking - ie, fade resistance. But the 'hoodie test' is just bad science. Sorry!
Where Porsche brakes shine is repeated braking - ie, fade resistance. But the 'hoodie test' is just bad science. Sorry!
zcacogp said:
johnfm said:
Just to be a boring science person, most cars are capable of the same braking g - its the tyre/road interface that is the limiting factor for braking g. If you look at most detailed car tests, braking times and distances are very, very similar for most performance cars...
I don't doubt you, but if this is the case, then what's the point of upgrading brakes? Oli.
People upgrade brakes for two reasons:
1) Bragging rights on internet forums
2) Fade resistance for track days.
Anyone who really thinks that upgrading brakes will stop a car in a shorter distance needs to read some books - if you want to stop quicker, you need stickier tyres.
johnfm said:
Contact patch has very little to do with it, as the retarding force acting at the tyre/road interface is a function of the coefficient of friction and the normal load.
So what you are saying is the same car travelling at x mph will stop in the same distance regardsless if it has 165 section or 205 section front tyres?
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