Sanity check: Hawk HP+ pads; there's noisy and there's noisy...

So I'd tucked the MGB away behind some other projects and decided it just needed too much everything to be any fun to drive right now. Fortunately Trent and our favorite Ethnic Food-Wrap Aficionado convinced me to get it sorted enough for an outing.

I replaced the front calipers and put a set of braided brake lines on. I'd previously refreshed the rear drums with Porterfield R4-S shoes, and I installed Hawk HP+ pads in the new calipers with Powerstop slotted rotors.

They squeal.

Like a champion pig-caller doing the "stuck pig" at point blank range.

Like every stool pigeon in history being interviewed through Disaster Area's amplifiers.

Has anybody had this experience and run them long enough to pass through a longer bed-in period and had them calm down? I was expecting some grindy noises or maybe some squeal. I was not braced for a piercing, protracted wail across the range of pedal pressure and for what feels like an eternity as everybody within half a block of the intersection cranes their necks to see what horror is unfolding. I honestly think it'll be hard to autocross for the desire to get off the brakes and make the noise stop.

Apart from the noise, they also seem to possibly fall off a cliff harder than I'd expected when cold (ambient on a warm day). Hawk does say the working range starts at 100F, but I didn't expect the graph to be so steep to the left of that. This also—and I continue to wonder whether they need more bedding-in—seems to result in a pad that is unpleasantly weak in normal driving but locks a wheel unexpectedly as the friction ramps with heat; like across one protracted stop it'll go from weaksauce to locked, but I only experienced that while doing my bedding-in drive; I haven't done any further spirited driving.

They promote it as "ideal for autocross," and it seems like a pad that doesn't work at all at ambient temps is a recipe for throwing away at least one's first run as the first few corners see brake torque all over the shop.

But I digress; if they won't quiet down I won't be able to stand them long enough to get to grips with other attributes. Anybody been through this? I also wonder whether this is compounded by the (lack of) rigidity of the brake and upright bits on a 50-year-old British sports car.

Had you used the rotors before with a different compound?  If so I'd take them off, spray them with some wheel cleaner and water until they're good and rusty, scrub the rust off with a Scotchbrite pad and re-bed them with the Hawks.

That said, I hate those pads.  Bad in the cold, lots of dust, noisy at times, and no real performance advantage compared to many OE pads.  I also hate slotted rotors and would much rather run plain iron parts store rotors.  Maybe it's just me.

In reply to ShinnyGroove (Forum Supporter) :

Brand new, carefully cleaned rotors. The Powerstops come with a sort of crosshatched machined finish I imagine to be intended to give some "tooth" for bedding.

Thanks for the data point; "noisy at times?" That sounds so mild compared to what I'm experiencing...

I have them on the front of my BMW currently, and yes they are far and away the loudest most ear piercing pads I have ever had.  Will not be purchasing them again.  So it's not just you.  

I've used the HP+ on multiple cars over the last 10+ years.  They only time I remember the noise being very bad was with the Evo 9 Brembo's on my S15, terrible just like you're describing.  They squeal occasionally on my Mustang but not bad enough that I gave much thought to it.  Always worked fine when cold for me.  I actually finally switched to something else because of how aggressive the initial bite is.  The dust is also terrible but stopping power was never an issue.

Did you bed them correctly?  Like the 5 or 6 consecutive stops from 60mph?  

Patientzero said:

Did you bed them correctly?  Like the 5 or 6 consecutive stops from 60mph?  

Hrm... I think I fell between some interestingly coincidental cracks. I just went back and looked at the box, and it looks like I was missing a step that came away with some badly placed tape. Moreover, what's there reads like the "street pad" bed in steps from https://www.hawkperformance.com/how-to and not the race pad ones, but it does look like I'm missing most of a chunk of text that looks a lot like it could be the 3rd step from the "motorsport pad" bed in steps (which otherwise doesn't match the first two steps from "street pad"). The HP+ are notionally "motorsport pads" in Hawk's categories.

Thanks, everybody, for the input. Sounds like some folks have had exactly my experience, but it also sounds like I need to go re-do the bedding process with one more tier of harder/faster braking.

Every set of Hawk's I've ever owned have squealed, including the HPS 5.0's currently on the S4. I will never use them again. Yes, all with new rotors and bedded in per the included instructions. 

The Hawks I had on my 986 originally were so dusty that brake dust went into the intake vents on the side of the car and permanently fouled the MAF. At least those stopped so hard your eyes hurt. Still squealed. 

The BeeGT in question. 

 

In reply to Trent :

It really does need to lose an inch up front, doesn't it?

Trent said:

The BeeGT in question. 

 

Who knew MGBs were so huge? 

HP+ pads SUCK.  They're extremely loud, they dust like crazy and they eat up your rotors.  They also melt at anything approaching track temps.

In reply to docwyte :

I think that's a bit dramatic.  

I use Hawk HP pads on my intrepid and the squeal was never terribly loud (but car was /is well insulated). They would squeal under light braking but never seemed to under mid to high braking force. 

Non ABS car, nose heavy FWD, 3519lb curb weight fwiw.  

My go to autox pad. Bed them properly, use them properly and you'll be happy. They are annoying as street pads. If you're fast enough on track to use them up you need a track pad not a Street/AX pad

When I ran them I found if they got a bit noisy (and they could for sure) a couple of hard stops out in the countryside to re-bed them did the trick. I found they worked well cold but there was a lot of dust (as expected). I believe the compound has changed though over the last few years so probably a different beast now. 

You could try using a high temperature brake grease on the backs of the pads and anywhere they contact the caliper to see if that helps. I always found the grease supplied with the pads would just turn to smoke/burn up the first time the brakes were really used hard.

It's unfortunately not at the top of my to-do list, but once I get back to the MG I'll break out the Permatex grease. I figured it was preferable to use Hawk's provided grease, but it's not shocking that it's there as a better than nothing as opposed to ideal.

In retrospect, though i do hope to get this car to the track, it's not even making 100hp... A performance street/AX pad would've been a better choice. Now I'm just sort of curious, and also not anxious to spend another ~$150 on pads, though that's likely where this is headed. I'll probably wind up with the EBC Greenstuff Trent recommended as a good general pad, or I might do the Porterfield R4-S because that's what the rear shoes are (and there's not much selection there) and there's a certain appeal to having both ends' characteristics match. OTOH being discs and drums probably outweighs compound differences in terms of character.

 It does seem like you can find plenty of people who *love* and who *hate* just about any pad. Given how much brakes affect the enjoyment of the car, it's not the spot to skimp in finding what you like.

In reply to Patientzero :

Not really as it's my experience with them

In reply to docwyte :

They obviously don't "suck" because many people have had lots of success with them.  They just have characteristics that you don't like which is fine.

I run these on both a light weight Lemons race car and my full weight 08 Mustang.   I get three races out of a set on the race car probably nine races on the rotors.  On the 08 I change them for track use then change back to street pads when I get home.   I have good luck with them.

They also do suck as a street pad, noisy, dirty, and eat rotors when cold.  I also ran them on a 1992 Mustang, they were grabby then bad when cold, but heated up quick.  Worked fine on the track in the 92 also.

Patientzero said:

In reply to docwyte :

They obviously don't "suck" because many people have had lots of success with them.  They just have characteristics that you don't like which is fine.

HP+ combine all the noise, dust, and rotor unfriendliness of a hard core race pad with the lack of high temperature tolerance of a street pad.  Worst of both worlds, I don't understand why they still sell them or why anyone ever buys them more than once.  They are literally the least useful of the dozens of different pad compounds I've tried.

So yeah, I agree with docwyte -- they suck.

Bang for the buck, they serve me very well and are cheaper than a Race pad.   Big rotors and cooling ducts help a lot.

I ran the Hawk Superduty pads (very similar to the HP+) on the Jeep for a while.  They were dead silent, but they were never great.  Braking power was great once you got enough heat into them.  But they were borderline scary in the cold (in the winter if the brakes were cold, a hard stop took close to a second of leaning on the pedal before you got any meaningful bite).  They dusted a decent bit (and it was hard to clean off) and ate rotors for lunch (on the fronts I wore 2 sets of rotors to min thickness and the pads still had 1/3 of their meat left). 

I eventually switched to Carbotech AX6s.  They cost more and dust even worse, but it cleans off much more easily.  Cold bite is dramatically better, total braking power is at least as good, they handle heat better (I managed to fade the Hawks once, I've pushed the Carbotechs harder and had no fade).  So far they're much more rotor friendly.  The only downside is that they do squeal a little every once in a while under light braking.  Braking at just a slightly different rate usually makes them shut up. 

Bringing this back up.

I had great results with HP+ pads in autoX, but that was 10+ years ago. If there are better autoX/aggressive street pads now, what are they?

codrus (Forum Supporter) said:

Patientzero said:

In reply to docwyte :

They obviously don't "suck" because many people have had lots of success with them.  They just have characteristics that you don't like which is fine.

HP+ combine all the noise, dust, and rotor unfriendliness of a hard core race pad with the lack of high temperature tolerance of a street pad.  Worst of both worlds, I don't understand why they still sell them or why anyone ever buys them more than once.  They are literally the least useful of the dozens of different pad compounds I've tried.

So yeah, I agree with docwyte -- they suck.

 

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