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rear disc replacement for drums

Discussion in 'Gen 2 Prius Accessories & Modifications' started by kryuenger, Sep 8, 2007.

  1. apriusfan

    apriusfan New Member

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    There is something the matter with the Consumer Reports test data set. Don't know what, but on a couple of cars that they list, my personal experience (with a gtech pro (www.gtechpro.com) performance meter) has a much better result. For example, if I read the list correctly, the Volvo S40 has a 60-0 stopping distance of 135 feet. My own testing of the brakes on a 2005 Volvo S40 T5 AWD (which is about 250 lbs heavier than non-AWD models) produced runs in the 115-120 foot range (in 2005, some of the car magazines were reporting 110 foot 60-0 results for the S40). If anything, tester error would result in longer runs, not shorter. I am not familiar with the CR testing protocol, but something is amiss. Another car that I have had better experience with than CR is the Volvo S60 - no way does it require 140 feet to stop from 60 mph. Maybe CR tests a car's brakes brand new without putting 300 - 400 break-in miles on the brakes????
     
  2. Boo

    Boo Boola Boola Member

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    <div class='quotetop'>QUOTE(apriusfan @ Sep 11 2007, 12:39 AM) [snapback]510456[/snapback]</div>
    I don't know. Maybe their brake testing protocol isn't great, but I assume that it's applied equally to the cars they test. So at least they presumably are comparing apples to apples, and our Prius apple only fares below average compared to the other apples.

    BTW, I had a Volvo 850 (the predecessor to the S60) and when Consumer Reports tested it they said that it had the best 60-0 braking distance of all the cars they ever tested - 122 feet.

    BTW, when I read different road tests of the same car, the braking distances almost always vary. Search braking distances of the current Prius and I think you will find, e.g., cnet showing a 60-0 braking distance of 152 feet and another magazine/tester showing a braking distance of around 125 feet.

    LAST BTW: I searched PriusChat for "braking distance" and found an earlier 5 page thread started by Brian of BT Tech regarding the issue of retrofitting rear disc brakes onto the Prius.
     
  3. apriusfan

    apriusfan New Member

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    <div class='quotetop'>QUOTE(Boo @ Sep 10 2007, 09:54 PM) [snapback]510467[/snapback]</div>
    Everything is relative.... Fortunately, there are things that can be done to improve the braking performance of the Prius.

    <div class='quotetop'>QUOTE(Boo @ Sep 10 2007, 09:54 PM) [snapback]510467[/snapback]</div>
    I too had an 850 (turbo version from 1995 to 2002, at which time I traded the 850 turbo for the 2002 S60 because it had AWD and DSTC). I agree whole-heartedly with the assessment of the 850's brakes. There were a number of times where I had to get on the brakes of the 850 real hard to avoid hitting someone who cut me off in traffic. The person behind me invariably would have to lock-up their brakes or have to change lanes to avoid rear-ending me.

    <div class='quotetop'>QUOTE(Boo @ Sep 10 2007, 09:54 PM) [snapback]510467[/snapback]</div>
    I always wonder how the testers manage to get such a wide variance (27 feet in the example you gave). Plus or minus 5 feet (even 10 feet) is one thing; but 27 feet????

    <div class='quotetop'>QUOTE(Boo @ Sep 10 2007, 09:54 PM) [snapback]510467[/snapback]</div>
    Interesting thread. Lots of discussion about regenerative braking; not much about what would be involved in converting the rear drums to disks.