hpd450

Hi. I am a new owner of a 2015 Porsche 911 GT3. I plan on tracking thee car this season and was wondering if anyone has some cold tire temperature setting for the stock tires-Michelin Pilot sports Cup 2 . Are people with this car using the stock brake pads on the car for track days and is anyone boiling the brake fluid at these events? By way of reference I have been doing track days and racing for 15 years with different cars and have always done my own work so I am only a noobie to this car. Thanks.

jmartpr

I can't help much on tire pressures as I track a GT4 but for the other stuff here's my opinion.
Brake fluid...the car is a 2015 model. When was it last changed? Regardless I would do a full flush with a quality brake fluid. I tend to prefer Castrol SRF, expensive but very good..
Brakes pads..same as above. When was it service? Stock or aftermarket pads? Thickness? PCCB or Steel brakes?
What tracks are you planing to go to? Length of hits/sessions and distance per lap? Does it has a lot of high-speed braking? All these answer will influence the choice of brake pad.
I would splurge on a new set of pads and forget about that....last thing you need is a pad disintegrating or damaging your disc on a track weekend.
I have done several track days in the past with OEM fluid and pads (not bad for OEM equipment and the car will do Ok) but since your car has a bit more time I would check and replace them anyway.

On the tire pressure you will probably start around 26-28 psi.....for MPSC2 I found the sweet spot between 31-32 psi hot. Keep tabs on the pressure and bleed accordingly. Have fun!

hpd450

The fluid has been flushed bur t the pads are oem with 7200 miles on them. Any suggestions on what aftermarket pads might be the best. I plan to run at LImerock, Watkins Glen, New Jersey motorsports park . Are you still running stock rotors? Bob

jmartpr

Bob....my GT4 is getting near the time for new rotors, Check for cracks between holes. A few of them is OK. 7200 doesn't sound like a lot...unless those are primarily track miles!
As for pads I like PFC 11....the initial bite is good and for our tracks (not very high-speed and 15 laps max per session) they are perfect. A lot of people also like Ferodos and Endless.

hpd450

Do you just use the pfc 11's for track days and replace them with stock pads or do you run them all of the time? also will you replace the rotors with oem or go with solids that are scored? Thanks for the info. What do you do for cold tire temps and what is your sweetspot? Thanks for the info. Bob

jmartpr

I use the PFC11s all the time...right now for the tracks we have and the amount of track time OEM would be my choice but for more heavy duty use (longer tracks/sessions) I would go for the aftermarket two piece as you can easily exchange the outer ring and save some $$$$ on the long run.
On Bridgestone RE71R I use 26 or 27 as a starting point and shoot for 30-32 psi. I'm using Pirelli DH slicks now on 19" and have to start at 26 and then bleed down....it would be around 23-24 psi cold.

Scooby921

Ditto on the brake fluid. I too use Castrol SRF. It's more expensive, but unlike everything else it retains a higher boiling point as it ages and absorbs water. Most others fall off significantly.

If your stock rotors are in good shape and the pads that are in there are OE, then I recommend Pagid RSL29 (yellow) pads. OEM pad supplier is also the parent company of Pagid so they tend to have material compatibility. There might be stronger, better pads out there, but the Pagid's are still fantastic and you won't need to buy new rotors if the current ones are in good shape. If your rotors need to be replaced then your pad options are open with no pad material compatibility to worry about.

In my car (981 GTS) I run the Pagid yellows all year. I'm too lazy to swap them in and out before and after every event. I don't daily drive the car because Michigan roads suck. It's generally a weekend car and I don't mind the low speed squealing. It's a bit humorous in stop-and-go traffic, but when I'm having fun on back roads I'm seldom going slow enough for the pads to make any noise. Between track and street I've averaging a little over 3k miles a year. OE rotors are dead after 10k miles and 6 track days. Stress fractures emanating from every cross-drilled hole. Pagid pads look to have 50% life remaining.

I've not run Michelin Cup 2's, but I do use RE71R's which are also a high performance street tire. My cold / hot pressure targets are the same as jmartpr. At the track I usually attend it takes 3-4 laps to warm up, but then I'm in good shape for the next 7-8 until the 20 minute session ends.