928 Stopping Distances?
12-15-2003, 06:07 AM
#16
Instructor
Originally posted by WallyP
Average of ten stops from 100 km/h was 2.94 sec, 35m per CAR magazine on an '89.
From 60 mph - 137 ft. per Road & Track on an '88.
From 70 mph in 183 ft. per Car & Driver on an '87.
From 60 mph in 156ft., from 80 mph in 280 ft. per Road & Track on an '84.
From 100 km/h in 40 m per a British magazine on an '83.
From 60 mph in 138 ft., from 80 mph in 248 ft. per Road & Track on an '81.
From 60 mph in 139 ft., from 80 mph in 248 ft. per Road & Track on a '78.
Average of ten stops from 100 km/h was 2.94 sec, 35m per CAR magazine on an '89.
From 60 mph - 137 ft. per Road & Track on an '88.
From 70 mph in 183 ft. per Car & Driver on an '87.
From 60 mph in 156ft., from 80 mph in 280 ft. per Road & Track on an '84.
From 100 km/h in 40 m per a British magazine on an '83.
From 60 mph in 138 ft., from 80 mph in 248 ft. per Road & Track on an '81.
From 60 mph in 139 ft., from 80 mph in 248 ft. per Road & Track on a '78.
12-15-2003, 10:00 AM
#17
Rennlist Member
Rennlist Site Sponsor
One point about brakes - bigger brakes only help on the second or third stop.
If the brakes are capable of sliding the wheels, stopping distance isn't affected by the brakes - the first time.
There are many, many factors that affect stopping distance. These include:
* Tires - a major factor. Size, tread compound, tread design, etc.
* Road surface - a big factor.
* Lubricant - the biggest factor by far. If the road surface has water, sand, leaves, gravel, etc. on it, stopping distances (and direction!) change dramatically.
* Suspension design - a big factor. How flat the tires are held while braking is probably the major effect, but anti-dive can also affect things.
* Brake balance - getting both ends of the car to work makes a big difference.
* Weight - pretty obvious.
There are others, but you get the idea.
It is important to note that brake feel is not usually directly related to brake performance. Really high-performance brakes often feel really crappy in normal driving. Brakes that feel really good in normal driving often have crappy high-performance characteristics.
Not a simple subject...
If the brakes are capable of sliding the wheels, stopping distance isn't affected by the brakes - the first time.
There are many, many factors that affect stopping distance. These include:
* Tires - a major factor. Size, tread compound, tread design, etc.
* Road surface - a big factor.
* Lubricant - the biggest factor by far. If the road surface has water, sand, leaves, gravel, etc. on it, stopping distances (and direction!) change dramatically.
* Suspension design - a big factor. How flat the tires are held while braking is probably the major effect, but anti-dive can also affect things.
* Brake balance - getting both ends of the car to work makes a big difference.
* Weight - pretty obvious.
There are others, but you get the idea.
It is important to note that brake feel is not usually directly related to brake performance. Really high-performance brakes often feel really crappy in normal driving. Brakes that feel really good in normal driving often have crappy high-performance characteristics.
Not a simple subject...
