Picking the right brake pad compound for our 997

Drilled rotors?  Really?  You like stress risers and cracks?

Welcome to the thrill of Porsche ownership! Tim's a restorer at heart, and just couldn't bring himself to put the wrong rotors on the car. It's been interesting watching him balance the desire to keep this car original and perfect with his desire to thrash it on track.

Andy Hollis said:

Drilled rotors?  Really?  You like stress risers and cracks?

Cheap Chinese rockauto blank rotors ftw!

Andy Hollis said:

Drilled rotors?  Really?  You like stress risers and cracks?

No worries...I expect the Hawk HP+ pads will have significant fade before reaching very high temperatures  and thus not thermally crack the rotors 

fusion66 said:

No worries...I expect the Hawk HP+ pads will have significant fade before reaching very high temperatures  and thus not thermally crack the rotors 

Yeah, I tried HP+ once and decided they were the worst of both worlds.  All the noise and dust of a true race pad, but none of the high temp capacity... :)

I have pretty limited experience with these pads on track on this car, and it was under less than ideal conditions, but I can say they have really good initial bite for a pad that can also get you to and from the track. But, yeah, they're messy.

I'm actually a big fan of Hawk's Street/Race compound, which we used on the S197 Mustang project. They're also filthy, as most Hawk pads are, but they make up for it my being a pad that excels at both low and high-speed competition, so long as you aren't running tons of laps back to back.

I'm curious to see what kind of rotor wear Tim gets from the HP+. That's really the rub with any truly good pad, is how quick do they grind up the rotors. If these can sustain the rotors, while providing enough capacity for the few track laps he's even going to need them for, maybe the dirt is worth putting up with. 

HP+ won't eat rotors in a few trackdays but you may find sessions at The FIRM limited by brake fade. I like HP+ as a good pad for someone who just caught the bug, bought a CAI and some pads and is going back. For serious work, Hawk DTC and Carbotech have much better temp range. HPS is a good DD pad, better modulation and bite than parts store pads for not that much more, in the grand scheme that is. 

I have tried to use the Hawk HP + before as a one and done dual purpose use pads.  But they are simply too noisy and way too freaking dirty for street use and not capable truly enough on the road course either. Basically had to "late brake" to make them work right and minimize the grinding noise on the street and would still got lots of disapproving looks at intersections.  I would consider them as an autocross use pad.  I have used the Hawk HPS pads for my toy's street driving and on most of the daily drivers. In the past I would typically switch out the toy's pads to Hawk Blue front and Hawk Black in the rear or (Carbotech XP-10 front and XP-08 rear) for road course duty.  I am sure there are newer pad materials now that maybe better.

BTW, what are those crazy, what appears to be ceramic rollers for on the stock pads?!?

deaconblue said:

BTW, what are those crazy, what appears to be ceramic rollers for on the stock pads?!?

Mass dampers for NVH reduction. The other downside to drilled rotors is they tend to make a lot of noise.

Agreed that HP+ are a good upgrade for a first-timer. When I was going through my 2 years of HPDE's with a nearly stock RX-8, they worked great for me. But now that I can get everything out of a car, they won't last for me. Hell, it's hard to get a stock-ish car to get tires to last, either, so it's all relative.
I LOVE Hawk's High Performance Street 5.0 pads for my road cars and I think a beginner could get by on them for their first few HPDE's, as well.

The DTC30's aren't on those charts, but on my Cayman I found them to hold up to pretty heavy track use and not be completely terrible on the street.  They weren't as noisy as the 60's, although they still dusted a lot and ate rotors when cold.

Also, those pad wear sensors are the worst.  A lot of people just cut off the pigtail and short the two wires with a crimp connector to keep the dashboard light permanently off.  I doubt if anyone on the GRM forum actually relies on pad wear sensors to tell them when their brake pads are getting low.

Blues, Blacks, HP+ -- IMHO pretty much any Hawk pad that isn't a DTC is obsolete other than the HPS, and even those have a new/improved version call "5.0".

HP+ is good for a lap and a half of our local track before fading into oblivion. We named the first turn at the track "the Ferber straight" after a new hire (and experienced autocrosser) went so far off he just about ended up on the interstate. 

 I'd never touch them after seeing that. 

Keith Tanner said:

HP+ is good for a lap and a half of our local track before fading into oblivion. We named the first turn at the track "the Ferber straight" after a new hire (and experienced autocrosser) went so far off he just about ended up on the interstate. 

Was that a stock Miata motor, or a 400 hp turbo car? :)

FM II, so about 250 rwhp. And some sort of street rubber circa 2007, not a cheater 200TW tire.  Still, a lap and a half! This is a kart track, so top speed couldn't have been more than 60 mph on that car. 

You literally picked the worst pad for every single situation.  Your experience with miata's is showing, this is not a tiny, underpowered, small tired car.  HP+ make noise and copious brake dust on the street, yet on the track will melt inside of a few laps with an experienced driver, like you.

Do yourself a huge favor and just throw them in the trash.  Run OEM textar pads for the street and a set of PFC08's or 11's on the track.  The drilled rotors are ok, but not as good as a set of Stebro slotted rotors. 

I've gotta say, the last few articles you've written on this car have really missed the mark and shown some things that are just flat out wrong, like "cleaning" the radiators.

Anyone worry about the compatibility of oddball rotor's hardness to various aftermarket pads?  Has to be some pro team has figured out wear, heat dissipation, alloys etc. 

dps214 said:

deaconblue said:

BTW, what are those crazy, what appears to be ceramic rollers for on the stock pads?!?

Mass dampers for NVH reduction. The other downside to drilled rotors is they tend to make a lot of noise.

You have got to be kidding!  Seriously?  What over engineered German nonsense is that?!?  How about just using slotted or smooth rotors? 

I agree with docwyte, just pony up and get the PFC pads that work great on the track. I use the 08's on my Cayman S and have never had any performance issues on the track. They seem to last a long time, and aren't too hard on the rotors, either. They even work pretty well on the street except for the track pad-on-the-street bugaboos of squeaking loudly and dusting like crazy.

I have seen the NHV pad "lollipops" on V8 Camaro Brembos and a few other applications.

Not to harp on Hawk pads (I run DTCs on the race car and love them), but I'll agree with the mediocrity of the HP+. There's a few other contenders in the "trackable street pad" category I'd probably pick first. Offerings from EBC, PFC, Carbotech, and Porterfield warrant consideration. Pad abuse factor really depends on vehicle weight, and that car is not a flyweight.

I never did understand why Porsche put drilled rotors on almost everything. Obviously there's a few engineers on staff who at least know their way around a brake rotor and understand the drawbacks. Drilling holes is not cheaper than not drilling them, so it's not cost. It is marginally lighter, but not enough. Of all the things to concede to the design department...

Just went thru this on my Cayman. I switched from Hawk Hp+ to Ferodo 2500's in front. The Ferodo's feel better, but I haven't been on the track with them yet.(They are a little noisier though). 

Ferodo DS2500's are ok, up to a point.  Once your pace increases, they're not going to hold up.  Just like any "dual use" pad, they're really not a track pad and eventually it shows.

docwyte said:

Ferodo DS2500's are ok, up to a point.  Once your pace increases, they're not going to hold up.  Just like any "dual use" pad, they're really not a track pad and eventually it shows.

They hold up OK in the sense that they remain functional at the cost of a very rapid wear rate.  I went through a set at NCM in like one Chin weekend.

Keith Tanner said:

HP+ is good for a lap and a half of our local track before fading into oblivion. We named the first turn at the track "the Ferber straight" after a new hire (and experienced autocrosser) went so far off he just about ended up on the interstate. 

 I'd never touch them after seeing that. 

Are you sure this was a brake pad issue as opposed to a driver error or some other issue with the brake system? I run the HP+ on my autocross/trackday/timetrial Miata (stock 1.8L) and have never had an issue with fade even when running 25 minute sessions at a pace that’s just a couple of seconds off the pointy end of a Spec Miata field. Then I can drive home on the same pads. They may not work on a heavy car or a fast car but they’ve been solid on my light slow car. The HP+ seems to get a bad rap on the internet from a lot people who’ve never actually used them because they’re not a “REAL” track pad. Not everybody wants to swap pads upon arrival and again prior to departure at the track.

docwyte said:

You literally picked the worst pad for every single situation.  Your experience with miata's is showing, this is not a tiny, underpowered, small tired car.  HP+ make noise and copious brake dust on the street, yet on the track will melt inside of a few laps with an experienced driver, like you.

Do yourself a huge favor and just throw them in the trash.  Run OEM textar pads for the street and a set of PFC08's or 11's on the track.  The drilled rotors are ok, but not as good as a set of Stebro slotted rotors. 

I've gotta say, the last few articles you've written on this car have really missed the mark and shown some things that are just flat out wrong, like "cleaning" the radiators.

Notice Tim hasn't posted the track testing article yet--the one where he'll actually write about how these pads work on the street and the track.

As the endurance racer on staff, I'll be perfectly honest that I don't believe there is such a thing as a dual-duty brake pad, and I've never driven on one that isn't a serious compromise. But I'm still open to the idea.

However, Tim's not racing this car; he's doing a few track day laps every once in a while for fun. And he's also not nearly as aggressive of a driver as he was 40 years ago (especially in his shiny Porsche).

It's our job to test things, as this would be a pretty boring outlet if all we ever did was make the most obvious choices every time for every project. This article was about installing pads; the next will be about driving on them. 

CrashDummy said:

Keith Tanner said:

HP+ is good for a lap and a half of our local track before fading into oblivion. We named the first turn at the track "the Ferber straight" after a new hire (and experienced autocrosser) went so far off he just about ended up on the interstate. 

 I'd never touch them after seeing that. 

Are you sure this was a brake pad issue as opposed to a driver error or some other issue with the brake system? I run the HP+ on my autocross/trackday/timetrial Miata (stock 1.8L) and have never had an issue with fade even when running 25 minute sessions at a pace that’s just a couple of seconds off the pointy end of a Spec Miata field. Then I can drive home on the same pads. They may not work on a heavy car or a fast car but they’ve been solid on my light slow car. The HP+ seems to get a bad rap on the internet from a lot people who’ve never actually used them because they’re not a “REAL” track pad. Not everybody wants to swap pads upon arrival and again prior to departure at the track.

Yup, pretty sure. The car never had a brake fade problem again. I do think he ignored some warning signs because he was trying to show off some speed to his new coworkers. The person who was riding with him could smell the pads. Smelly pads points straight to overheating.

There are many other options out there, and too many questions about that pad to make it the choice. The R4S, for example, shows temps running up to 1300F on the friction vs temp chart. Hawk doesn't even show a curve past 800 for the HP+, which tells you a lot about intended use. Maybe a car with a lot more grip than power can make them work on the right track since there isn't all that much braking involved, but it's definitely not on the list of pads I'd recommend to anyone who is planning on going on track.

In my experience, the PFC97 is a do-anything pad, from running cold and wet in a hurricane to dealing with a V8 Miata on track. They just always get the job done. They'll take out two sets of rotors for every set of pads, though. Depending on your choice of rotors, that might actually be less expensive than if the use was the other way around :)

Tom Suddard said:

docwyte said:

You literally picked the worst pad for every single situation.  Your experience with miata's is showing, this is not a tiny, underpowered, small tired car.  HP+ make noise and copious brake dust on the street, yet on the track will melt inside of a few laps with an experienced driver, like you.

Do yourself a huge favor and just throw them in the trash.  Run OEM textar pads for the street and a set of PFC08's or 11's on the track.  The drilled rotors are ok, but not as good as a set of Stebro slotted rotors. 

I've gotta say, the last few articles you've written on this car have really missed the mark and shown some things that are just flat out wrong, like "cleaning" the radiators.

Notice Tim hasn't posted the track testing article yet--the one where he'll actually write about how these pads work on the street and the track.

As the endurance racer on staff, I'll be perfectly honest that I don't believe there is such a thing as a dual-duty brake pad, and I've never driven on one that isn't a serious compromise. But I'm still open to the idea.

However, Tim's not racing this car; he's doing a few track day laps every once in a while for fun. And he's also not nearly as aggressive of a driver as he was 40 years ago (especially in his shiny Porsche).

It's our job to test things, as this would be a pretty boring outlet if all we ever did was make the most obvious choices every time for every project. This article was about installing pads; the next will be about driving on them. 

Yeah, but there's "less obvious choices" and then there's "obviously wrong choices".

dps214 said:

Tom Suddard said:

docwyte said:

You literally picked the worst pad for every single situation.  Your experience with miata's is showing, this is not a tiny, underpowered, small tired car.  HP+ make noise and copious brake dust on the street, yet on the track will melt inside of a few laps with an experienced driver, like you.

Do yourself a huge favor and just throw them in the trash.  Run OEM textar pads for the street and a set of PFC08's or 11's on the track.  The drilled rotors are ok, but not as good as a set of Stebro slotted rotors. 

I've gotta say, the last few articles you've written on this car have really missed the mark and shown some things that are just flat out wrong, like "cleaning" the radiators.

Notice Tim hasn't posted the track testing article yet--the one where he'll actually write about how these pads work on the street and the track.

As the endurance racer on staff, I'll be perfectly honest that I don't believe there is such a thing as a dual-duty brake pad, and I've never driven on one that isn't a serious compromise. But I'm still open to the idea.

However, Tim's not racing this car; he's doing a few track day laps every once in a while for fun. And he's also not nearly as aggressive of a driver as he was 40 years ago (especially in his shiny Porsche).

It's our job to test things, as this would be a pretty boring outlet if all we ever did was make the most obvious choices every time for every project. This article was about installing pads; the next will be about driving on them. 

Yeah, but there's "less obvious choices" and then there's "obviously wrong choices".

Given GRM's relationship with Tire Rack and the fact that the friction graphs have Tire Rack logos on them, I suspect a lot of the pad options suggested here weren't really on the table. TR sells Hawk, Stoptech/Centric and Akebono. There are loads of options in the Hawk line though.

Tim, Tom,  thank you for this series of articles! This is exactly why I love GRM, because they offer a variety of approaches that appeal to various members of our community (racers, hardcore HPDE, casual HPDE, etc). I am particularly interested in your approach with the 997, because I am in the same situation. I went from a dedicated track car (Evo 8 RS) to a street car (Audi TT RS) that I want to keep civil and relatively stock, but still have fun with on the track occasionally, without going back into the black hole of never-ending mods and chasing lap times... I have been very happy with Endless products (brake pads and fluid). I drove my track car to/from the tracks and their race compounds have performed well on the street, with good cold bite and little/no noise (for me, YMMV), and, since they have a very wide range (almost "Endless") of compounds, I was able to find the compound I needed as my speed increased (ME20 - ME22 - N35S - N05U - N05S). I am now using their street/track compound, CC-Rg, and have been very happy with it on the street and on the track (while driving accordingly, but still within a few seconds of the track car). They can be a little difficult to obtain (I order the pads directly from Japan) and relatively pricey (although Yen-USD is favorable at the moment), but worth it to me for their "near-unicorn" abilities.

In reply to Keith Tanner :

IIRC Tim was working with Pagid, too, but had some issues finding the right pad shape. Hooray for Tire Rack's catalog!

Dumb question here: Do brake coefficient of friction ratings matter on pads? I've seen some rockauto special's that are HH rated. So one can't help but think that they should be good for track use?

My carbotech xp10's didn't have any coefficient of friction ratings on them, but they're clearly a track pad or at least work on track!

Lsxus said:

Dumb question here: Do brake coefficient of friction ratings matter on pads? I've seen some rockauto special's that are HH rated. So one can't help but think that they should be good for track use?

My carbotech xp10's didn't have any coefficient of friction ratings on them, but they're clearly a track pad or at least work on track!

From a quick google it looks like the "high temp" part of that rating is only 600-650*F so it's not really enough information to tell how a pad will do on track.

In reply to Tom Suddard :

I mean, ok.  If you're doing easy laps, fine.  But then you get to deal with the car sounding like a garbage truck on the street.  I've definitely btdt, there is no magic bullet for a brake pad that can handle a powerful, relatively heavy car with an experienced driver on track and still be quiet, have good brake torque and not ruin brake rotors/wheels on the street.

The closest are Ferodo DS2500 and Porterfield R4S.  If you're constrained by what an advertiser is giving you for free, then perhaps a line about that is in order.

Someone mentioned EBC pads, I tried three different compounds (green, yellow, and orange) and none of them worked on track on my 2.7 Boxster. They all juddered like crazy once hot, and faded. Yes, I bedded them in correctly. I finally gave up and tried the PFCs and they have worked great on track. My old Boxster is slower and lighter than the 997 in question, so I think the EBCs would work even worse on the 911.

If Tim is taking it really easy while on track, then much of the advice here may not apply.