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Old 01-25-2012, 06:58 PM   #16 (permalink)
johnunit
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Quote:
Originally Posted by p38fln View Post
OK, I searched NHTSA and found their research - they are saying discs stop faster in their testing. They used real trucks and real drivers to do the testing, no computer simulations. A total of 108 drivers were used. I got tired of reading and just copied the important details -
*Edit - read further into it - The stopping distance from full panic stop numbers are from a real truck, the 108 drivers were to test reaction time using a simulator

Anyway, i was completely wrong about the numbers- they aren't cutting in half from 600 to 300 feet, more like 30%.

Full panic stop from 60 MPH -
Regular S-Cam and drum - 317 feet
Enhanced S-Cam and drum - 252 feet
Air disc - 222 feet

http://www.nhtsa.gov/DOT/NHTSA/NVS/V...ons/811367.pdf

This document has the research on stopping distances - the previous one was just research on how drivers responded to better brakes
http://www.nhtsa.gov/DOT/NHTSA/NRD/M...OTHS809700.pdf
This is interesting, and compels me to make a correction to my previous statement (last post on previous page):

I assumed that a truck took "3 or 4 times" as long to stop from highway speeds as a car.

With an average car, in good repair, taking 120-170 feet to stop from 60, and trucks taking 317, the stopping distance for a truck is notably less than "3 or 4 times" the distance for a car.

While I suspect a majority of trucks actually on the road would struggle to equal the NHTSA numbers, it does mean I've been overestimating the reaction time I have behind a truck in a panic-stop situation.
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