Is the Porterfield R4-S more like the Hawk HPS or the Hawk HP+?

 

I haven't used any Hawk products but I will tell you that the R4-S is a great street pad but NOT for use on the track. With a stock-power FD on street tires, the R4-S begin to melt and deposit all over your rotors making them shimmy and shake for weeks after the event. All that without showing any signs of fading. It happened to me several times in a row (and to others I've talked to as well) so now I swap in R4 pads in the front for track events which work great.

 

I run a n/a FC on the track and got very good braking performance from HP+ pads, though they smear on the front (without fade). I have purchased Hawk HT-10 pads for the front, and retain the HP+ for the rear. I will note that the HP+ sucks as a street pad - it likes to be warm to get any appreciable bite. I didn't get smear until I started running R-compound tires and could brake MUCH deeper without lockup, though power level from FD to FC are very different.

If you are running an FC in autocross or HPDE-type events, you will like the HP+ pads. They are kind to rotors, though they dust quite a bit. However, if you are a track rat, there will be a day when you surpass their abilities.