zoiks

Folks, I bought a 991.1 C2S a few weeks ago and hope to continue doing 4 or so HPDE's per year. I have about 14 years of experience and I am a PCA HPDE instructor. This is my first Porsche (love it!) and I am headed to get it ready for HPDE. My previous car had a StopTech 4-piston BBK with the 2-piece floating rotors which I loved. I would run Hawk DTC-70 front, HT-10 rear and I loved this combination. I really like the initial bite of the DTC-70's and the finesse that it took to modulate the brakes. I had tons of tire options and would usually run the Bridgestone RE-71R's or some Dunlop Direzza's. I could always find really good deals on those tires. I also had adjustable camber arms and would typically run -3.0 to -3.3 degrees negative camber. From what I've seen at the track the Porsche's can run with a lot less camber and have good even tire wear. I have several questions that I hope folks can help me with:

1. Rear 295's or 305's? The prices don't look a lot different. Is there any preferences folks have for HPDE's? I know there is lot more to just going wider.
2. I always drive to and from the tracks. What's the best tire that balances price and performance? I don't see any of the Dunlop or Bridgestone options I used to use and it looks like Pirelli or Michelin's are about the only reasonable options. I see a lot of positive comments on the Michelin Pilot Sport 4S but the comments seemed to be on these tires being a great street tire. Are they acceptable for the track? I'm not clear if the Pirelli's are good track tires? It then pushes you into the Michelin Pilot Sport Cup 2 tires. And from everything I've heard at the tracks folks love these tires. Some of the other streetable track/competition tires are way more expensive then the Michelin's so I'm staying away from those.
3. What brake pads do folks recommend? I see a few other threads on this topic. I really like the DTC-70's/HT-10's and have run those for 14 years. I see a lot of comments on Pagid's. I don't care about noise since I swap out the pads for street/track.
4. I pan to upgrade to the GIRODISC rotors. Does anyone sell these for less than $2400 for the front and rear sets or is the price basically fixed everywhere? Any recommendations on who to buy them from?
5. I also plan to upgrade to the caliper stud kit...same question as #4, any recommendations on who to buy from?
6. On the GIRODISC rotors, I read somewhere that you can run the "larger" GT3 brake pad in the front. Or something to that effect? Can someone explain this to me and let me know what p/n's or details I would need to order that? Does doing this screw up the front to rear bias?
7. When removing the front and rear calipers, brackets, etc..are there any special tools / sockets required? I've only swapped rims to date on my 991.1S but the pictures of the fasteners look unique? What sockets/wrenches do I need? When I add the caliper stud kit does that also drive some unique tools?
8. What is the maximum factory negative camber you can get on a 991.1? Are folks adjusting this for HPDE's or leaving it at a stock setting? How is the tire wear if you are leaving it at a stock setting? I know on my past track car I really regretted waiting so long to buy adjustable camber arms. Running at -3.0 degrees camber instantly resulted in even tire wear and I got a lot more life out of my tires.
9. For folks that upgrade to adjustable front camber, what would you recommend? What are the best kits out there? What's absolute camber adjustment can you get to?
10. Any other recommendations / suggestions?

Thanks for all of the help!

erko1905

Disclaimer: I'm not at your experience level but I'll give it a quick try on a few items:

1) 305 for sure (quite a few 991 variations come w 305s from factory anyway)

2) From my research I found that options at 245/35/20f & 305/30/20r sizes are limited to Michelin Cup2 (reasonably fast, streetable) and Pirelli Trofeo R (faster than Cup2, a bit less streetable, wears uber fast, expensive). If you were trailering, Hoosier apparently just started making these sizes as well. If you have slightly wider wheels (something like a Sport Techno for example, 1/2 in wider) you do have 255/35/20 & 315/30/20 available in Toyo R888R, but I heard so many failures of that at this point that I'm convinced it's not safe -- given your prior experience level I'd skip the Pilot Sport 4S, it doesn't have that much grip. (I think there are Dunlop Maxx Race's as well but they're somehow never available)

3) I think the only two options are Pagid RSL29 yellows and Ferodo DS1.11 for this car. Pagid is the enduro compound w less initial bite, Ferodo has a bit more initial bite, which makes it a bit more streetable as well, this item seems purely personal preference. I don't like the Pagid yellows personally.

4) If you can find the hats used from someone, you could buy the rotor rings only - if not, I couldn't find any discounts myself, but I might not have tried hard enough. Apex Performance carries them.

6) Yes, apparently it's the same caliper in the front, I'd ask about this to Apex - I think there is a thread on this somewhere on here

8/9) I think roughly around -1.3 to -1.5 in the front is the max from factory. I would definitely not leave it on "stock" setting ie run on track w the street spec alignment. Front camber maxed out, using street tires (PS4S) I got almost even, slight more outside wear last season. I'm fairly sure it'd be too little camber for grippier R-comp tires. There are quite a few options on the front LCAs - I currently have the RSS one. Tarett makes one too I believe. I don't think you'll end up needing as extreme a camber as -3.0 with this car though - that's up to you to experiment with.

Good luck and glad to see another 991 on track.

Mr. Turtles

I ran in the Black run group at PCA (so less experience than yourself) with a 2012 and 2015 991.1s. I'll answer based on my experience at Mont Tremblant, Mosport, Calabogie and Watkins Glen.

1. 305's for sure the extra width can't hurt and they fit on the stock rims
2. MPSC2's - these will give you 2+ seconds on the track vs the P4s or Pzero (which I hate). BUT if you don't care about those 2 seconds and want great street tires that you can also track go for the Michelin P4S (plus they are great in the rain). The MPSC2s will give you about 12-16 good sessions and then fall off quickly with about 4-8 more in them depending on driving style and track. The MPSC2s are not trackable safely in the rain. The P4Ss will last a little longer. I've also hear good things about the RE71R's (see Orthojoe's comments) but I have no experience with them.
3. Brake pads - as previous poster mentioned only a couple choices. I was running Pagid RS29. Loved them on the track but noisy on the street.
4. Girodisc are great and thats what I ran. Price is similar everywhere. Call Clarke at APEX performance.net and he will give you a discount. Small business with very good service.
5. Tarrett but I just heard that Girodisc may have their own. Clarke would know. ( and no I don't get a % from him, me and couple friends have had great experience with him)
6. I believe that Girodiscs are 350mm all around for the 991S. Clarke would know appropriate fitment.
7. not sure
8. My local "guy" maxed out the allowable camber which I heard was around 1.8. It worked very well for the 991s and the MPSC2s wore very evenly when pushed hard.
9. not sure as I didn't need more camber. I would try out the maxed out camber setting before spending money on major changes.
10. Consider getting the AWE wind deflectors. Their is a lot of wind buffeting in the 991.

Enjoy its a great car. The Giro's would last through about 2 sets of Pagids over about 20 track days.

zoiks

Mr. Turtles

Jabs1542

JRitt@essex

Gents,

Before anyone goes too far down the brake upgrade path, please keep in mind that we are going to be developing our Essex Designed AP Racing Radi-CAL Competition Brake Kits for these cars. By the time you are done spending money on discs, pads, lines, studs, and bolting on MC's and calipers from other trim levels, you will have spent a large chunk of money that could have gone towards a more complete solution that offers additional benefits and retains more value.

We already have complete systems for the 987/981/718 Cayman and Boxster, the 991 GT3, 981 GT4, and one in the works for the 997 chassis cars. We'd like to get a 991 Carrera S into our shop to measure. If you know of anyone interested in loaning us their car, please PM me. We just returned the blue GT3 to its owner, and we have a 997 GTS in the shop now. Thank you very much.

You can see details on our kits in these threads:

The one we would develop for the 991.1 would be most similar to the kit described in this thread: https://rennlist.com/forums/997-foru...l#post14955585

https://rennlist.com/forums/porsche-...l#post14960532

Our kit for the 991 GT3 is a bit larger:
https://rennlist.com/forums/991-gt3-...finally-7.html

etchhead

Looking forward to seeing if there is another option for 380/350mm PCCB rotors.

zoiks

Jay, thanks for all of the information. On the caliper studs...Tarett Engineering said I only needed the sleeves for the rear stud kit. Did you need those sleeves for the front too? The email from them said "you shouldn't need the sleeves for the front." 95 mm studs for all 4 corners but the 95 mm sleeves only go on the rear according to Tarett. If you say you must have the sleeves in the front too I'll give them a call back since something doesn't sound right. It sounds like you only ran the Girodiscs in the front. I'm headed to order the Girodiscs I'm just checking prices since everyone seems to be locked in at $2400 for the front and rear set. I did get the complete bracket and line stud kit too so it should be a great set up. Now I just need Tirerack to have all the tires in stock at one time.

Cheers, KRW