Hawk HPS vs Akebono SP pads and rotor temperatures

[fenixus]

oh my ... today I fixed the dragging front brakes on my wife's '00 Solara 5s-fe. pads were dragging on rotors, because all slide pins got stuck in Winter (Permatex Ultra sucks, I switched to Permatex Ceramic Extreme). after I finished I took the car for a test drive applying hard braking force when slowing down on highway exit ramp (confirmed slightly warped rotors, nothing major) and then moderately & lightly braking down in city driving until I reached the parking lot... brakes were not dragging at all

temperature reading results taken with digital non-contact thermometer (HFT, $9 or so) shocked me, I dropped my jaw on the floor ...

1)
'00 Solara SE 5s-fe (front calipers and rear drums)
front: Hawk HPS pads @ 15k miles with original OEM rotors (never resurfaced) @ 80k miles
rear: old drums in rear, original shoes, adjusted a tad too tight and catching at 3-6 clicks on parking brake handle (should be 5-8).

front wheels outer rim 100-110F
front wheels center hub 60F
front rotors over 220F basically my thermometer said "Hi" (it means out of scale on my thermometer) !!!

2)
'02 Solara SLE 1mz-fe (front calipers and rear calipers with e-brake drums)
front: Akebono SP pads @ 1.5k miles with original OEM rotors (resurfaced) @ 125.5k miles
rear: Akebono ProACT pads @ 1.5k miles with original OEM rotors (resurfaced) @ 125.5k miles

front wheels outer rim 80F
front wheels center hub 60F
front rotors 130-140F
(numbers from before wheel bearings were replaced, actual results may be a little different now)


Does your HAWK HPS pads heat up rotors that bad too?


The Funniest thing is that Hawk HPS on i4 have actually a little less braking force than Akebono SP on V6 ... maybe rear calipers and resurfaced rotors make the difference

will be re-surfacing front rotors on wife's car soon. wondering if flatter rotors will generate less heat (more braking force with brake pedal less depressed) ...

from Hawk website:
"HAwk HPS pads (...) gentle on rotors" <-- yeah sure ... and I am a Santa Claus ...

[wilsonman02]

There could be a farily easy answer. I'm pretty sure the V6 vehicle has larger rotors and dual piston calipers which also means larger brake pads. So given the same braking distance and force the larger rotors and pads on the V6 would disapate heat much better and keep the brakes cooler. Also allowing more aggressive braking for a longer period of time. With the smaller pads and rotors you applying the same force to a smaller area which will have more friction and more heat.

[iovaykind]

That seems too big of a difference though. I think a good idea would be (if you had the time and money) to switch to either hawk or akebono on both and test it again. Doesn't seem to make sense to test two different brands on two different applications and compare their performance. But it does seem fishy though.

[fenixus]

Originally Posted by wilsonman02

There could be a farily easy answer. I'm pretty sure the V6 vehicle has larger rotors and dual piston calipers which also means larger brake pads. So given the same braking distance and force the larger rotors and pads on the V6 would disapate heat much better and keep the brakes cooler. Also allowing more aggressive braking for a longer period of time. With the smaller pads and rotors you applying the same force to a smaller area which will have more friction and more heat.

nope.

Solara V6 has EXACTLY same calipers as Solara i4 (single piston design and same part numbers for calipers), so it pretty much means rotors are exactly same as well. Both pads are also same size/type/shape as well (inter-changeable).

Originally Posted by iovaykind

That seems too big of a difference though. I think a good idea would be (if you had the time and money) to switch to either hawk or akebono on both and test it again. Doesn't seem to make sense to test two different brands on two different applications and compare their performance. But it does seem fishy though.

both applications are same, only engine weight is different (and suspension springs are heavier on V6), both cars are almost identical except for rear brakes.

[fenixus]

forgot to mention, V6 is equipped with ABS (no traction control) while i4 has no ABS, but it shouldn't matter in above test as I never applied brakes so hard that wheels skid.

so, anybody else with Hawk HPS pads willing to measure temps on the front rotors for comparison?

EDIT:

just for the record here are part numbers of front pads used in test:
a) V6: ASP707 (Akebono Street Performance)
b) i4: HB320F.669 (Hawk HPS)

Both models of pads fit either of vehicles used in the test.

I *could* (but won't do) swap the pads between cars and compare further, but I am not going to do that.
Hawk HPS calls for some bed in steps while Akebonos don't. With that being said, I don't even know how Hawk HPS pads will work after rotor resurfacing, e.g. they may start squeaking like hell.

besides i4 rotors are screaming for a resurface, don't want to destroy almost brand new Akebono pads on them.

I don't know front rotor diameter on those cars, but they must be same.

[N/A Camry Sleeper]

Just a guess here but I would think that the Hawk pads since they are higher performance would generate more heat since they are able to stop the car better - if you buy into all that marketing crap.

There are a lot of variables in this expermient - as you said the wheel bearings have been replaced so that may play a role in the final temp...Was the outside temperature the same with both runs? Did you use the same route for both vehicles? Also, the resurfaced rotors vs the original rotors will have an effect...the original rotors likely are a little glazed to some degree AND would be a tad less efficient in stopping the vehicle (more heat generated to do the same amount of work)

Just a thought though...

[fenixus]

thanks N/A Camry Sleeper. my next step is to resurface rotors on i4 and re-do the test again with both cars. next time on exactly same route and with similar braking force at every stop or slow down.

you are right, the route was a little different (more highway running on V6, but then city route was pretty much same) and ambient temp was different, but not too much (10F difference maybe).

thing is that I was measuring V6 rotors multiple times at different occasions before when tracking down brake drag vs wheel bearing problem in Winter (came up it was both LOL ) and I have NEVER seen V6 rotors hotter than 145F even with shot wheel bearings (completely seized, car was running on hubs) and dragging brakes (stuck caliper pins)... so far it's crazy hot on i4.
...perhaps seized bearings (rubbing hubs) behaved like an extra braking force, so pads had less work to do on V6 to stop the car?

and I hope the unevenness of i4's rotors contributes to the result (inefficient brakes, more heat, less braking).

will post back fresh results in a few days.