555ss

I have the essex ap kit 4 piston, the new upright or knuckle, skf race hubs and my pad wear is just like the picture after a 2 day event I flip them side for side and all is well I am using the ferodo 1.11 deep pads they are also wearing more at the top( outside) than at the bottom but that is just from caliper flex.
The new knuckle does make a differance but it does not eliminate it at hard braking tracks like NHMS, Thompson The taper is much less at the glenn or Pocono I have had the Essex kit and the new knuckles for this whole season 7, 2 day and one 3 day events and I have used only 1 set of 1.11 pads 1/2 way thru the 2nd and this is a heavy 3395 lb car on 315 a6's with abs still active that i beat like a rented mule....

naschmitz

Hey Bob!

I was getting about twice the taper using those extra radial depth pads than the standard radial depth pads. I quit using them.

Bert

RX-Ben

I don't think the deep pads wear from caliper flex - I think the inside (closest to the axle) wears less b/c it is seeing less disc speed and is farthest from the pistons, so it is relatively unsupported.

kmagvette

ding, ding, ding

Radial taper seems to be more prevalent the smaller the disk gets. The deeper depth pads show the taper more because of the distance bottom->top is greater for a given angle of taper. I get measurable, hardly visible, radial pad taper on my behemoth fronts as well.

I do the unthinkable and square up the pads on a disk sander. No idea if the calipers are happier pushing square on a pad; my gut says that the piston force on the pad is more on-axis with a square pad rather than one with radial taper and that pushing on-axis can't be a bad thing for the caliper bores.

naschmitz

I was getting twice the pad taper, top to bottom, with the larger radial depth pads. Inner to outer taper was not the problem.

RX-Ben

Very curious. I'll take a look at mine tomorrow and report back.

kmagvette

When I said "diatance bottom->top..." I meant radially. I should have been more clear.

555ss

Hey Burt!!
Hope all is well, We miss seeing you at the track.
I have been getting a long pedal late on the second day I am thinking I have to switch side for side at the end of each day....
We have had a great year both cars are close to championships Laura has been flying 2:07 at the GLEN except for a mechanical at thompson she would have won every TT so far I found the fence at the Glen between 8 and 9 still ran 2:09:0 after a tie rod end and some duct tape...

Bob

naschmitz

Hi Bob,

You and Laura are kicking butt this year. I saw she got an FTD too, right?

I developed a long and inconsistent pedal too with the AP T1 kit that I could not fix until I did both of these things:

1. Clean the Hawk brake pad paint residue off the pistons -- that is some nasty crap to be pushing into the bores and the pistons were sticking.
   
2. Replace my Hardbar rotor hats. With 6000 track miles on that hardware and who knows how many heat cycles, torquing those fasteners to spec still left a lot of movement of the rotor out of plane, knocking the pads around. I switched to KNS DBA two piece rotors and all was good again.

Amazing how much lap time you gain when you have confidence in your brakes! I did a lap at VIR within a second of my personal best with 29 heat cycle R6s after these fixes. If those tires would have been in their sweet spot I would have blown away my personal best by 2 seconds.

Bert

555ss

[
I developed a long and inconsistent pedal too with the AP T1 kit that I could not fix until I did both of these things:

1. Clean the Hawk brake pad paint residue off the pistons -- that is some nasty crap to be pushing into the bores and the pistons were sticking.
   
2. Replace my Hardbar rotor hats. With 6000 track miles on that hardware and who knows how many heat cycles, torquing those fasteners to spec still left a lot of movement of the rotor out of plane, knocking the pads around. I switched to KNS DBA two piece rotors and all was good again.

Amazing how much lap time you gain when you have confidence in your brakes! I did a lap at VIR within a second of my personal best with 29 heat cycle R6s after these fixes. If those tires would have been in their sweet spot I would have blown away my personal best by 2 seconds.

Bert[/QUOTE]

Yes she did get an FTD and that makes 2 one last year in the rain.... my car is kinda tired 88 k miles 5k 0n track, hers has 44K ...LOL
THanks for the tip My pedal starts out good but gets long still hard once it gets there and once switched and beat on for a bit it comes back.
My kit has the essex hats /brackets, I checked run out > .005 so that is fine I have spare rings in the truck just incase
Still a huge inprovement over the stock brakes and uprights... like 2 different cars.
Bob

Bluefire

I had the opportunity today to swap out my new Carbotech XP12 track pads with the 1521 street pads after my recent track day. I can report that there was zero pad taper (in either direction) on the XP12's. Rotors are 352 mm x 32 mm. Pads run the full 54 mm sweep area.

Olitho

You will probably need more than one track day to show the taper. It is also very dependent upon tire brand, model, compound, and track grip, plus the length and intensity of the brake zones.

Bluefire

You're correct Oli. There wasn't a ton of wear. To level set, I ran relatively new Hankook Rs3's (140 tw), clean, dry track (Portland Int. Raceway). The end of the front straight is a decent brake zone from ~130 -> 40 MPH. Back straight is a little less intense brake zone. Skill level... I'm an "intermediate" noob with about 15 track days under my belt.

Now, track days are over until next year.