Porterfield R4-S Pads -- Revised?

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Series8217
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Porterfield R4-S Pads -- Revised?

Post by Series8217 »

A new set of Porterfield R4-S pads just came in. The edges are heavily chamfered. There is at least 10% less total material on the pads vs the old ones, and the initial contact area is about 75% of what it used to be, until the pads wear down to about 20%. and the back has some foil stuck to it with anti-squeal goop underneath.

None of the pads in the set (listed for "1988 Pontiac Fiero Front or Rear") have the pins on the back to keep the rear piston from spinning when the ebrake is actuated. It used to be that all the 88 pad sets came with two that had pins to fit into the face of the piston.

Are the pins not actually necessary?
CincinnatiFiero
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Re: Porterfield R4-S Pads -- Revised?

Post by CincinnatiFiero »

My cheap pep boys pads did not have them, the front and rear pads were the same part number. My rear e-brake functions, not particularly well.

Did you notice an improvement with the R4S pads? Looking at possible upgrades to my 88 as I am looking more and more into another swap.
AkursedX
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Re: Porterfield R4-S Pads -- Revised?

Post by AkursedX »

CincinnatiFiero wrote: Did you notice an improvement with the R4S pads? Looking at possible upgrades to my 88 as I am looking more and more into another swap.
To be honest, I am not all that impressed with them. For a street application, I don't recommend them. They just don't have great stopping power when cold. Now put some heat in them and they are AMAZING. If you plan on auto-xing your car or going to track days, then I say go for the porterfields. But if you plan on DD'ing the car, they are not worth it IMO and you'll be fine with a regular set of pads


I plan on switching out my rear's soon for some cheap-o pads so I can hold some boost at the line.
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jelly2m81
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Re: Porterfield R4-S Pads -- Revised?

Post by jelly2m81 »

CincinnatiFiero wrote:My cheap pep boys pads did not have them, the front and rear pads were the same part number. My rear e-brake functions, not particularly well.
I do believe you just found your e-brake problem.

yes those pins are important, they keep the piston from turning with the screw
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Series8217
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Re: Porterfield R4-S Pads -- Revised?

Post by Series8217 »

AkursedX wrote: To be honest, I am not all that impressed with them. For a street application, I don't recommend them. They just don't have great stopping power when cold. Now put some heat in them and they are AMAZING. If you plan on auto-xing your car or going to track days, then I say go for the porterfields. But if you plan on DD'ing the car, they are not worth it IMO and you'll be fine with a regular set of pads
How cold is it when you have problems?
I have been running R4-S pads for over 3 years and have never experienced poor cold braking. I've driven in temperatures down to about 30*F (that's cold in California :-P).

CincinnatiFiero wrote:Did you notice an improvement with the R4S pads? Looking at possible upgrades to my 88 as I am looking more and more into another swap.
Before my 12" brake rotor upgrade, all I did was change out standard pads for the Porterfield pads. The difference was ridiculous. I won't go back to stock pads. Stock rotors weren't enough to keep from fading though, so I upgraded to 12" with the same pads. The braking force didn't change much, but I haven't managed to fade them.
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