Re: 1990 GT Rotors and Calipers

..boB wrote:
dwight wrote:
".boB" <bobcowan@xxxxxxxxxxxxxxxxxxxxxx> wrote in message news:44ff5d6f$0$21437$ec3e2dad@xxxxxxxxxxxxxxxxxxxxxxxxx

dwight wrote:


I have aquestion about rotors and calipers on a 1990 GT.

Slotted/drilled/dimpled rotors are for looks only. They actually decrease brake performance over a stock type solid rotor. It's all about surface contact area.

Oh, I have to disagree strongly with this. In theory, that may be true, but the stock Mustang rotors on my '93s were CRAP. The PowerSlots GREATLY improved braking on both of my cars.

Think how much better they would be with more surface area.


I think more about heat. As in the voluminous clouds of white smoke coming from my stock rotors.

dwight


Then something is wrong. I use a stock replacement solid rotor front and rear. I spent the day at the track yesterday; really wailing on those brakes. Hard into turn one from 130 to 60 in about 2-3 car lengths. Over and over, 30 minutes at a time. They smell good, but never smoke.

Brakes work by converting rotational energy into heat energy through friction. Greater friction occurs with increased surface contact area. Cutting slots and drilling holes decreases surface area of the rotor. It's like saying, "I need better brakes, so I'll install smaller rotors." Doesn't make sense.

The original purpose for drilling and slotting rotors had nothing to do with temperature control In the olden days, racing pads would outgass under heavy use. The gas pocket would get trapped under the pad, and prevent contact. The holes and slots were there to allow the gas to escape. Modern brake pads don't outgass, so there's no need for that. Modern replacement rotors are drilled/dimpled/slotted because people like the look, and don't use their brakes enough for it to matter. They're for the ricer and wannabe racer crowd.

Brakes that need extra cooling should have a better vanes, and more air flow into the center of the rotor. That's how cooling occurs.

For more information, look to the FAQ pages of companies like Baer Brakes and Wilwood.

But, if you really think you get better braking with smaller rotors, then one of two things happened. 1. Your brakes were so bad before that almost anything would be an improvement. Or, 2. You've spent all that money on bad decisions, so you'll stick by your guns no matter what, facts be damned.


OMG I think you're full of sheepdip.

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Relevant Pages

  • Re: 1990 GT Rotors and Calipers
    ... Slotted/drilled/dimpled rotors are for looks only. ... decrease brake performance over a stock type solid rotor. ... It's like saying, "I need better brakes, so I'll install smaller rotors." ... Modern brake pads don't outgass, so there's no need for that. ...
    (rec.autos.makers.ford.mustang)
  • Re: e39 rotor recommendation
    ... That's why at the end of the story about the crap brakes that I bought before I knew they were crap brakes, and I paid $200 for 4 rotors and all of the pads, I said that one should expect to pay about $50 per rotor and $50 per set of pads, to get reasonably good stuff, and way better stuff than what I got. ...
    (alt.autos.bmw)
  • Re: Accord 2003 Brake Vibration Problem No Dealer can fix!
    ... Of course we don't know how Luc drives, but I suspect you are right. ... fly by me over the speed limit, then slam on the brakes just before ... Your rotors should never be resurfaced as the process removes material ... Honda Accord 2003 and I changed disks & pads last years. ...
    (rec.autos.makers.honda)
  • Re: 1990 GT Rotors and Calipers
    ... decrease brake performance over a stock type solid rotor. ... but the stock Mustang rotors on my '93s were CRAP. ... As in the voluminous clouds of white smoke coming from my stock rotors. ... Brakes work by converting rotational energy into heat energy through friction. ...
    (rec.autos.makers.ford.mustang)
  • Re: Steering wheel shaking during braking
    ... Personally, I'd get new rotors. ... handbrake act on the rear service brakes (not so with my L series that has ... I had a stuck pad on my LW300. ... Car was recently aligned. ...
    (rec.autos.makers.saturn)