Porterfield Pads

[abes]

What has your experience been with the RS4 Street pads? Ever since I installed these pads on my car (83 zx which sees zero track time) I've had issues with my braking system. Do they need to heat up to work properly or do they work as standard pad; just able to resist more heat, less fade?

 

I installed them with intentions of upgrading the stock system along with s.s lines, ATE Super Blue, Vented disks in the front and new disks on the rear- bled the entire system. The brakes have not been the same since the upgrades. They actually suck right now. I've gone as far as even replacing the master cylinder and bleeding the entire system numerous times. I try slamming the brakes and they come to a "faded" stop but no locking up. Its scary as I feel that if someone was to stop in front of me I would probably slam into them.

 

Can it be the pads just aren't made to be a street, daily driven pad or do guys think otherwise?? Brake booster is the only thing left to replace through the system.

 

Please let me know your experiences.

 

Many Thanks.....

[Miles]

What procedure did you use to bed-in the new pads?

Edited April 9, 2011 by Miles

[NewZed]

Pads are easy to change. Did you toss the old ones? Or just buy some cheap stock style replacement pads as a benchmark.

[abes]

As far as bedding them., I pretty much drove the car as normal. After some time I would come from a 50 mph to a sudden stop- a few times.

[JMortensen]

They worked fine for me on the street and at autoxes. No need to heat them up before they worked. The R4 needs heat and it's like having no brakes at all before the heat gets into them, but the R4S should work great on the street. I wonder if you might have gotten the wrong pads... might be worth a call to Porterfield.

[Miles]

I researched the R4S pads for my 240Z and most of the Honda, Mazda, BMW and Nissan sites report that the R4S pads have a good initial bite and improved braking performance as a street pad. I recall more positive then negative reports.The recurring complaint was about dust.

 

I haven't installed the R4S pads yet, but will bed them in when I do install them.

 

Perhaps if someone here has had a bad experience with R4S pads they will chime in.

Edited April 9, 2011 by Miles

[JMortensen]

I had a bad experience trying to use them as a track pad. That's not what they're for though.

 

[Tony D]

I would say that's more a maintenance interval issue than a pad issue...

 

I have run R4S on just about everything. The fluid needs to be good, you will be able to (on an S30) get the center hub VERY hot under repetitive hard braking (no fade for me...) to the point I would recommend synthetic greases up front.

 

Bedding of an R4S does not involve 50mph casual stops alone. I literally made the rotors glow red with (if I recall their procedure) three 100mph to zero stops in rapid succession and then driving around till I felt they were cool enough. That was after several moderate stops to bring up the rotor temperature. Break-in has to get pad material onto the rotor, if the rotor isn't slightly bluish after some of the stops, you weren't braking hard enough. Don't come to a complete stop, keep rolling and repeat---try to do it without lockup of any wheel.

 

I'm thinking you glazed the pads from a timid driving and break-in. You will have to scuff your pads and thoroughly clean the rotor surface and properly re-bed them to get even frictional deposition on the rotor surface or they will never work properly. This is not a pad issue, this is a 'failure to follow installation issue.'

 

I also concur on the brake dust. They make a nasty black dust. They also stop exceedingly well. They will lift my fat arse up off the seat and onto the belts under hard braking...and that's after several 80 and 100 mile per hour 'panic' stops. Actually on the last bedding stop, I kept pressing and pressing harder and harder and the car was progressively stopping faster and faster. It was kind of spooky how well they gripped the hotter they got. But I drive them daily, and the only other complaint I would have is that they squeal louder than Ned Beatty under casual or very light braking. It goes away immediately as I stab the pedal and the car abruptly stops...but it's not conducive to my rear bumper longevity driving around SoCal!

 

Dust and Squealing I guess are the downside. If you don't have first rate fluid, you may as well not even bother installing them. I used RBF600, I think 650 is available now. The pads will have the ability to get the bearing center of the rotor carrier (hub) to the point where normal DOT3 will boil (300+F) imagine the caliper heat level! Good (some would say superior) brake fluid is required to get the most from these pads. And sticky tires won't hurt.

[DrSideways]

Make sure the metal backing plate of the pad is not binding in the caliper. You can use the bench grinder to take a bit of metal off of the backer plate on the fore and aft edges. I have seen the pads bind here and while you are exerting good pedal pressure the pad may not be squeezing the rotor.

 

Another thing you can do before putting the pads back in. Take a sheet of 100 grit sand paper and put it on a smooth flat surface. Then put the pad side down on the paper. Move the pad in a figure 8 pattern. You will take the glaze off evenly.

 

Put the pads back in. Flush with new fluid if you haven't. Bleed all four corners. Then bed the pads again. There may be bedding instructions in the box they came in, or the Porterfield website.

 

Hope this helps.

 

Alan

[z-ya]

I have the R4S on my street Z. No issues. Firm pedal, good bite.

[Miles]

I have the R4S on my street Z. No issues. Firm pedal, good bite.

 

 

How did you bed the pads?

[johnc]

On stock S30 front calipers the R4S won't last very long on the track. The R4 doesn't last much longer either. Porterfield upgraded the R4 to a R4E material for heavy duty track use but I've never run those.

 

The local ITS racers ran Hawk Blues as a minimum and many had Porterfield custom cut HT10s or PFC 97s. The OEM front brakes on a S30 get very hot with track use (over 1,000F by my IR heat gun measurements in the hot pits) which is tough for any pad. R4S has a max temp of around 800F.

 

Regarding the OP's original post, the R4S is a good performance street pad with good bite. You list a bunch of mods in your post, were those done at the same time as the pad change to the R4S?

[ashintar]

Did you upgrade to the 15/16 master cylinder? If so you might just need to adjust the pushrod.

 

http://forums.hybridz.org/index.php/topic/91174-brakes-get-progressively-worse

[z-ya]

How did you bed the pads?

 

Basically I did what most suggest for bedding new pads.

 

Do a hand full of near-stops from 50-60mph to about 10-15 mph. Do it by pressing the brakes firmly, but not hard enough to lock the wheels. At the end of each slowdown, accelerate back to 60mph and then apply the brakes again. After bedding when you come to a stop remove your foot from the pedal, shut off the engine, a put the car in gear instead of using the parking brake. Allow the brakes to cool.

[z-ya]

Did you upgrade to the 15/16 master cylinder? If so you might just need to adjust the pushrod.

 

http://forums.hybridz.org/index.php/topic/91174-brakes-get-progressively-worse

 

Installing a 15/16" MC on a Z with stock brakes will only increase pedal pressure, making it feel like the brakes are not working very well. Stick with the 7/8" MC when running stock brakes. Even with the 240SX rear disc conversion.