Jason987.2

I see that Porterfield R4 (old school) are dirt cheap compared to PFC 08's and Pagid yellows.

What are their downsides? I plan to swap them for track days, either at home, or at trackside.

Are their transfer layer on the rotors compatible with the stock pads?

TIA

T&T Racing

I run Porterfield R4 on my Porsche 944 race car and are happy with them. The R4 is gentle on the rotor.

Cannot answer if the transfer layer is compatible with stock pads.

Most 944 race cars use Cobalt pads,http://www.cobaltfriction.com/Default.asp. I purchased front and rear sets for my next brake pad change. The higher coefficient of friction for the front Cobalt pads compared to the rear, similar to R4, increases the brake bias to the front.

stownsen914

I used Porterfields for years on my 914 racecar in my avatar. I was happy with their performance, though possibly not a great comparison if you are running a newer car. One thing I'll tell you is wash your wheels well after every event if you use Porterfields! The brake dust must have higher metal content, and will rust and glue itself to your wheels if it gets wet (even high humidity seemed to do it too). Total PITA to get off at that point. I switched brands because of it.

Scott

mcipseric

R4s are great pads for the track! very easy on rotors.

Cory M

Call Porterfield and ask: https://www.porterfield-brakes.com/ They sell all 3 of the brands in question (and more) and have excellent customer service. The R4 is an older compund and not too agressive. Based on Porterfield's recommendation I'm running R4's on my Miata but just on the rear for better balance.

g-50cab

I've used the R4's for years - easy on the rotors - in my experience much better suited for lighter cars - above a certain temperature they tend to glaze a little more than the new compound