usctrojanGT3

I'm running a 987.2 spec Cayman S track car that's 2,700lbs....I was thinking of using a pad with a little more bite in the rear versus the front to get rid of some slight ABS instances. Does you recommend recommend the DS1.11 in the front and DSUNO in the rears to get a little more brake bias for the rear? Also, I'm running the larger Girodiscs rotors in the front (340mm) and rear (325mm)...does AP Racing make these larger rotors for the 987.2 Cayman S?

JRitt@essex

Yes, DSUNO rear with the DS1.11 front will shift a little bias towards the rear. The mu difference between the two isn't tremendous, and shouldn't upset things.

On the discs, yes, we are working on expanding our line of two-piece discs for non-GT vehicles. We just released our two-piece AP Racing discs for the other 991 trim levels, and we're evaluating other models as well (including the Cayman and Boxster). Please stay tuned, and feel free to jeff.ritter@essexparts.com at any time. Thanks!

JRitt@essex

Yes, these are now shipping. Part numbers are:
FCP4664G
FCP4665G

Robert Linton

How does that compound compare with Pagid RSC 1?

JRitt@essex

I don't know that we've ever run the Pagid RSC1 on our dyno, so I can't provide too much input. Also, RSC1 is designed for use on carbon ceramic discs, so I have no idea how they'd perform on iron discs.

sasportas

Just ran the DS3.12's this past weekend on my 991.2 GT3.

Previously I had been running the DS1.11's with good success and rotor longevity.

Well.....so far so good. Easy brake modulation, no ABS activation, or rotor issues.

Here's the interesting objective findings:

Solo DL 2 data analysis of brake pressure for identical zones on a known local track are consistently decreased by 300-400 psi on heavy braking (end of straights), and decreased by approximately 100-150 for less aggressive braking areas of the track.

Very confident braking from the out lap if the system was warm from a previous run (within an hour).

Good even transfer of pad material to disc. Absolutely no shuttering.

Minimal to no fade after 30 minute sessions.

Only bad thing is that I need to re-train my brain and foot so as to compensate for the decreased pedal application. I also lost .5 seconds per lap because I was over slowing into the initial turn in from a long straight. I'll fix that next time out.

JRitt@essex

Thank you very much for the data and feedback. We really appreciate it! Your comments make sense, and they match our expectations based on dyno and data from other customers. Positive impressions have been pouring in, and we're definitely excited about what we've seen it do thus far. Once people wrap their head around the slightly higher mu, they really begin to exploit this compound.

Have you noticed any squealing noise? The odd thing we keep hearing from customers is that the DS3.12 is completely silent. I noticed this firsthand on my Corvette track car.

Thanks again!

FYI...we only have a few sets of the second batch of these pads remaining on the shelf and ready to ship if anyone wants to try them. More are on order, but no ETA on those yet.

aalencar

Very interesting. Just swapped from PCCB to AP racing for now with Ferodo 1.11. Compared to PCCB I need more pressure on pedal for same braking power. Experiencing some “thumping” coming from rear brakes (feel on seat and hear it). It comes on very heavy braking and assume it may be related to ABS? Your 991.2 is MT or PDK? You had steel brakes before? Wonder where the difference is.

sasportas

Steel brakes.

No thumping.

Had a little squeal in winter with DS1.11's.

Haven't heard a peep from the DS3.12's.

Clark-ApexPerformance

Thanks for your report. The fact they are quiet is an added bonus. I have these pads (DS3.12) in stock but they are not yet on our website. Call to order.

Mech33

I installed and ran a set of DS3.12 from Apex last week at Laguna Seca and thought they were great! Very consistent, and a nice uniform transfer later in the discs with no strange deposits or vibration. Looking forward to getting some more days on them.

krell

Three boxes from Clark at Apex arrived at my front door yesterday with AP rotors and some brake lines in preparation for the track season.

erko1905

I'm trying to quickly sift through all the 991.2 track prep threads but meanwhile for a few brake related questions, this might be the right thread:

DS3.12 is meant to be the newer & better DS1.11, or it's a different compound and will coexist w the 1.11?

Is the jury still out on the AP vs Giro rotors? For the 991.1/2 GT3, they both seem to be similar price, both 380mm? Would the Tarett brake caliper studs meant for the Giros also work w the APs? Any advantages/disadvantages specific to either?

Finally - is the OEM brake pad & rotor & fluid setup usable at all at the track? I remember the Carrera pads melted pretty fast, fluid was definitely a no go, and rotors were shot fairly quick as well as they develop cracks between the drilled holes. I'm wondering whether the optimal behavior is to pull the OEM pads rotors from day one, preserve those and start w the track appropriate rotor+pad+Motul 600?

Mech33

They are certainly different, and my understanding is they will continue to coexist.

There are fans of both rotors, and they both seem like solid hardware. The main differences I'm aware of are the AP rotors use J-hook slots, while the Girodiscs use straight slots. I've had some whirring under braking from the J-hooks sliding past the pad surface, but I haven't heard if Girodisc users experience similar things.

The Tarett brake caliper studs just replace the OEM caliper bolts, so they are generally compatible with anything that is compatible with the OEM calipers (including both the AP and the Girodisc rotors).

Note that Girodisc now sells their own brake caliper stud kit at the same price as the Tarett parts, but they actually use a fully stainless front stud in addition to the fully stainless rear stud (while Tarett uses an OEM cup car coated steel stud in the front, which can rust over time).

I've run OEM fluid at the track and it's been fine under some pretty heavy use, but ultimately I've switched over to Castrol SRF.

While the stock rotors develop cracks, so do the AP and Girodisc rotors even relatively early into their lifetimes, so I wouldn't expect that to go away with any of the iron rotor setups.

erko1905

Very helpful, thank you.