pfb

Took out the S2000 with new Porterfields R4S's and ATE Super Blue.

Did some threshold braking and had major green fade! I'd read about green fade before, but never experienced it! Lots of smoke coming from the front brakes and very little braking force. I had been attempting to bed in the brakes before the threshold braking, but I guess I didn't boil off enough of the trapped volatiles.

I thought that R4S's where "carbon/metallic" and that carbon pads were less suseptable to green fade than other types of pads?

Also, changing the front pads is very quick. Does anyone switch to a track-only pad for track days? Would it be acceptable to change out only the front pads?

cdelena

I

pfb

I thought it might be bleed problems, but braking was excellent before and after the fade incident... If I boiled the fluid or had air in the lines, wouldn't my brakes stay spongy?

Did you get lots of smoke from your brakes after aggressive testing? I sure did!

cdelena

You are probably right, if it was the fluid the feel would not come back completely. I guess you found the limits of the pads.

I also had billowing smoke when I forced fade, but it was pretty hard to do. Took pretty hard running doing 0-70-0 runs over and over. Most track conditions will not be that hard on the brakes.

I like the higher friction of the R4S but can see that it is harder on the rotors. The stock pads are great until you get them very hot on the track. Eventually I will wind up swapping pads between street and race, but I

pfb

I agree with the swap idea. Especially if you have race rubber, and are lifting the car and removing the wheels anyway. It seems that is the majority of the work of swapping the pads anyway.

I bet I could swap front pads in less than 2 minutes a side once the car is up on jacks and the wheels off. I might get a couple of extra shim plates and keep them on the pads.

CoralDoc

Chris - I'm installing the R4S pads on my car this week in anticipation of a track event at Sebring on Sunday. I will be taking a shallow cut on the rotors to smooth out some small ridges that formed on my last outing and plan to follow the bed-in procedure that you outlined earlier. Any other tips or tricks to consider? BTW, pfb, once you burn through a set of stock pads like I did during the last event, you'll have the extra set of shims that you need for the Porterfields .

gregstevens

Joshua, I will be interested to see how you like the R's at Sebring. Make sure to post afterwards...

Also, I missed Chris' expo on bedding the pads, can someone post a link, please?

Have a great time at Sebring, Joshua...too bad that Sondra won't be there to provide some 360 degree entertainment!

cdelena

R-4 CARBON KEVLAR BEDDING IN PROCEDURE All disc pad materials require a period of bedding in before they are subjected to severe braking under racing conditions. Because of the special characteristics of Porterfield R-4 disc pads a very special bedding procedure is necessary to ensure that they will achieve their full potential. When a satisfactory contact has been made between pad and disc the brakes should be used progressively harder until a falling off in performance is felt (brake fade). This is best done by continually braking from medium speed until, at the end of one such stop, a substantial increase in effort is needed to reduce the speed of the car. Brake parts will be very hot by this time and it is very important to now allow the pads to cool and recover, preferably with the vehicle still on the move. If the above advice is followed, Porterfield R-4 disc brake pads will give long and fade free braking, coupled with good performance and disc condition .

CoralDoc

[QUOTE]Originally posted by gregstevens:
[B]Joshua, I will be interested to see how you like the R's at Sebring.

cdelena

[QUOTE]Originally posted by CoralDoc:
[B] Here's my review: I loved 'em!

The Porterfield R4S pads made a significant improvement in brake performance yesterday.