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Jetsetsurfshop
Hey paddock people,
Need brake rotors that will last at least a season.
Heres the stats on my brakes
1976 911 5-lug
19mm master
Hawk pads dtc-70 (front and rear)
Zimmerman drilled and rotors
I'm getting tiny cracks around the drilled holes of the rotor. I'm sure the Hawk pads are to blame. Under normal driving conditions I bet these rotors will last a good while. AutoX and Sebring is killing them.
So....any good rotor ideas?
Stoptech and Centric are out there for my 911 set-up. Anyone got anything to say on these or any other advice?
biggrin.gif
Shane


brant
Cool carbon break pads.
Now called kfp.

6 years on my rotors so far with 2 drivers.
You don't need drilled rotors.
Power slotted if you if you want
Jetsetsurfshop
QUOTE(brant @ Apr 14 2014, 04:14 PM) *

Cool carbon break pads.
Now called kfp.

6 years on my rotors so far with 2 drivers.
You don't need drilled rotors.
Power slotted if you if you want


What rotors are you using too sir?
Shane
Matt Romanowski
All drilled rotors crack. It's not a problem until the cracks between holes connect or the cracks get to the edge of the rotor. Post up a picture of what you have.
tscrihfield
QUOTE(brant @ Apr 14 2014, 08:14 PM) *

Cool carbon break pads.
Now called kfp.

6 years on my rotors so far with 2 drivers.
You don't need drilled rotors.
Power slotted if you if you want

agree.gif

The drilled rotors were created for asbestos outgassing. Since we no longer have that in our pads it is really unnecessary. The slotted rotors are good but, solid face vented rotors are as well. The problem with drilled rotors are that they are going to crack, it's just a matter of time.

Never used the KFP pads but knowing how Brant uses his car I'd say he's good source for this type of info.

Jetsetsurfshop
QUOTE(Matt Romanowski @ Apr 14 2014, 04:55 PM) *

All drilled rotors crack. It's not a problem until the cracks between holes connect or the cracks get to the edge of the rotor. Post up a picture of what you have.


Here's the rotors I just pulled off the car. I hope the photos work, posting from my phone.
sad.gif
Jetsetsurfshop
I guess it worked.
Here's a closer look.
Shane
Jetsetsurfshop
QUOTE(tscrihfield @ Apr 14 2014, 04:55 PM) *

QUOTE(brant @ Apr 14 2014, 08:14 PM) *

Cool carbon break pads.
Now called kfp.

6 years on my rotors so far with 2 drivers.
You don't need drilled rotors.
Power slotted if you if you want

agree.gif

The drilled rotors were created for asbestos outgassing. Since we no longer have that in our pads it is really unnecessary. The slotted rotors are good but, solid face vented rotors are as well. The problem with drilled rotors are that they are going to crack, it's just a matter of time.

Never used the KFP pads but knowing how Brant uses his car I'd say he's good source for this type of info.


Didn't know that about drilled rotors. Good info. I just thought they were there to help with cooling.
wobbletop
Yours are definitely worn. Most drilled rotors will have some chamfering around the holes to reduce cracking. Yours either didn't have those, or it's worn past the chamfering. I'd stick with blank rotors, or if you want to get fancy, use J-hook rotors.

Hawk pads can be tougher on rotors than other pads.

I've tried quite a few pads and currently am running PF01 pads. They have good initial bite and are easier on the rotors. They tend to squeal when cold though.
Randal
QUOTE(wobbletop @ Apr 15 2014, 08:27 AM) *

Yours are definitely worn. Most drilled rotors will have some chamfering around the holes to reduce cracking. Yours either didn't have those, or it's worn past the chamfering. I'd stick with blank rotors, or if you want to get fancy, use J-hook rotors.

Hawk pads can be tougher on rotors than other pads.

I've tried quite a few pads and currently am running PF01 pads. They have good initial bite and are easier on the rotors. They tend to squeal when cold though.



+1 on the chamfering.

Without chamfering you end up with a hole with a 90 degree angle to the rotors which cuts pads; this is according to a big time professional mechanic and racer I know.

We were going to cut the rotors on my son's MB compressor, but cutting the pads would eliminate the chamfer area. You'd end up with a 90 degree angle which cuts pads. Bought new rotors instead.
Seabird
Another way to tell its time for new rotors is the delta in thickness from new. I think total allowable wear is in the neighborhood of 2mm. I can see in the pictures there is a concave radius on the inside edge of the rotor face; I bet your past the 2mm's. You got your moneys worth out of these.
Paragon
You can do Sebro Slotted Rotors for a little over $80 ea.
brant
QUOTE(Jetsetsurfshop @ Apr 14 2014, 06:52 PM) *

QUOTE(brant @ Apr 14 2014, 04:14 PM) *

Cool carbon break pads.
Now called kfp.

6 years on my rotors so far with 2 drivers.
You don't need drilled rotors.
Power slotted if you if you want


What rotors are you using too sir?
Shane



my fronts are 911 vented rotors from ATE with the eliptical slotting
they were really only a few dollars more than standard replacements

my rears are 914/6 non vented stock rotors
I had a machinist create the power slotting in them

I'm not really sure the slotting is even necessary or that beneficial
the right pads make the most difference
I played with KFP on a 944Turbo and the car was really too heavy for them
the hawks were superior on that car...

but most of the pads are created for the common street performance market cars... corvettes, 911s, 944's, mustangs.... cars that weigh 3000lbs
so a lot of the pad compounds don't work on a 914, even if they are the best pad you can get for your heavy car.

kind of like tires, its all about the compound operating range
I am going to do some brake temp testing this spring on the track for my car
but there are some sweet compounds out there for lighter cars
the KFP may or may not be the best
but it is definitely a good compound, and rotor friendly

brant
ChrisFoley
I've been completely satisfied with KFP pads as long as I've been racing my 914.
That's why it's what we sell.
jhadler
Drilled rotors are not necessary in almost any application these days. Especially for a car that sees daily driver use.

Even formula 1 cars don't cross drill the rotors. Granted, they're carbon rotors, and have forced internal venting.

Now... If you're really into autox, and you're looking at reducing unsprung mass as much as ridiculously possible, you might consider something like this...

Click to view attachment

But plan on replacing those rotors frequently. And yes, this picture is from a legitimate competition car that won multiple national championships.

-Josh
Randal
QUOTE(jhadler @ Apr 16 2014, 12:14 PM) *

Drilled rotors are not necessary in almost any application these days. Especially for a car that sees daily driver use.

Even formula 1 cars don't cross drill the rotors. Granted, they're carbon rotors, and have forced internal venting.

Now... If you're really into autox, and you're looking at reducing unsprung mass as much as ridiculously possible, you might consider something like this...

Click to view attachment

But plan on replacing those rotors frequently. And yes, this picture is from a legitimate competition car that won multiple national championships.

-Josh


Must have worn out some tooling drilling those 150 odd holes!
Jetsetsurfshop
QUOTE(jhadler @ Apr 16 2014, 11:14 AM) *

Drilled rotors are not necessary in almost any application these days. Especially for a car that sees daily driver use.

Even formula 1 cars don't cross drill the rotors. Granted, they're carbon rotors, and have forced internal venting.

Now... If you're really into autox, and you're looking at reducing unsprung mass as much as ridiculously possible, you might consider something like this...

Click to view attachment

But plan on replacing those rotors frequently. And yes, this picture is from a legitimate competition car that won multiple national championships.

-Josh


Wow, impressive!
Matt Romanowski
If those rotors are thick enough, they are fine. The cracks look ok in the photos.
Jetsetsurfshop
I already replaced the ones in the pictures with a new set of Zimmermans. Was thinking about my next set.
I've looked at the Sebros.
What about Centric or Stoptech?
Anyone try these?
Shane
ThePaintedMan
How about these guys? They're a pretty big hit with Chumpcar ->

Frozen Rotors
Trekkor
My experience with KFP Gold pads has been bad.

They last 8-9 hours and worn to the metal under endurance race conditions.
Raybestos ST-43's last as long as 50 hours. Rotor friendly.

Vented rotors, no slots or drilling.
tomeric914
Bringing back the semi-dead...

The OP's rotors were fine as the cracks didn't connect the holes.

Add enough heat and any rotor will crack drilled, slotted or not. This is a 2 year old Zimmerman with about 30 track days running Porterfield R4 pads and brake ducts. Scary? No. The car slowed from an indicated 130 with no drama lap after lap. I certainly will be replacing these but it's a small price to pay for a helluva lot of fun!

Click to view attachment
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