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Not sure you can increase the size of the rotors with base size calipers. I think you would need to upgrade to S calipers in order to increase the size of rotors.
I am in the process of upgrading calipers from a base 991.1 to S. Bought used S brakes calipers from a rennlister. Based on my research the front rotor size is different on a S versus base while the rear rotors are same. There is a thread on here where someone mentioned that S calipers will work with base rotors. Since I am upgrading I just purchased new rotors from fcpeuro and will send back the base one I bought from them earlier.
Not sure you can increase the size of the rotors with base size calipers. I think you would need to upgrade to S calipers in order to increase the size of rotors.
You can but you need spacers and longer caliper bolts. Note the pad will no longer reach all the way to the hat so you will see some rust after a rain or wash. That said, it can easily be cleaned off with a scrub pad.
While we are at it can you guys confirm a few things please. I have a base 991.1 and have front and rear S calipers that were given to me and i want to install these with new rotors, pads, and ss brake lines. I was planning on just upgrading the rotors to OEM S parts, 340mm front and 330mm rear. After reading this thread it looks like with the S calipers you can easily go to 350mm front and rear rotors for a 997 turbo. The only modification needed to use the 350mm rotors is that the rear calipers will need spacers and longer bolts. The fronts don't need any modifications at all. Is this correct? After looking at FCP the 350mm rotors are actually cheaper than the 991 S rotors so if i'm upgrading, why wouldn't I upgrade to the 350mm rotors? Is there any reason not to?
Just wanted to followup on this thread, finally did the brake upgrade. If you have a 991.1S, there is NO reason not to do this. The 350mm 997.2 turbo rotors fit perfectly with 997.2 turbo caliper bolts (rears are 10mm taller than front) and the spacers from (https://www.extsw.com/collections/1-...a-thick-316-ss). I did the Endless MX72 pads (GT3 size up front) from nengun (made to order, so it took a few months to come in) and SS lines from fcpeuro. Have not even bedded in the pads but already the pedal feel is 100% better than stock.
Here are the parts for my swap on a 18 991.2 GTS
All of these parts can be found on fcpeuro site with lifetime exchange. The only thing you need is the 12mm spacers that apex might sell you if you ask nice! Lol I talked giro into sending me some but they did it reluctantly. I talked to a lot of track guys and the roi on the sebro rotors was a lot better than ap racing j hooks or giro. They don’t look as cool but will do the job!
First, thanks a BUNCH for this. I assume you're on center-lock wheels, right? 2 years on, any regrets with this setup? I am a bit of an OEM+ type of guy and this is exactly the kind of upgrade I like to do when possible.
First, thanks a BUNCH for this. I assume you're on center-lock wheels, right? 2 years on, any regrets with this setup? I am a bit of an OEM+ type of guy and this is exactly the kind of upgrade I like to do when possible.
No issues with center-lock wheels on this set up, I'm very happy with it. About 8-10 track days and rotors and pads are holding up exceptionally well! Just do it!
Yep. I found a vendor who supposedly already has the spacer/bolt kits ready to go, and have spoken with a couple knowledgable Porsche experts who both suggested the same off the shelf 350mm front/rear rotor that should work...
I think I am going to pull the trigger... Right now its looking like about $450 drilled/$550 slotted for rotors + $115 for caliper spacers/bolts. This would cover all four wheels.
Pads I am debating Endless MX72 vs Endless MX72+, GT3 size front pad.
Do you think you would like to share the vendor you purchased the rotors and spacers from?
I don't have the dedication or time to read all 9 pages of this "old" post. There is the probability my comments below are redundant, apologies if that is the case.
History: I have a 2017 Carrera GTS. It comes with 350mm front and 330mm rear rotors. My stock front rotors, with some 26,000 miles and 3 track days with Pagid RS 19 pads were near their wear limits. I did the research and found cheap rotors from FCP, and also sourced the rotors from Gaudin Porsche in Las Vegas, NV, my preferred Porsche OEM Parts supplier. Gaudin charges about $600 for a set of 350 mm front rotors, no CA sales tax, and possibly free shipping. FCP prices are similar.
But in my heart that was not what I really wanted....I wanted to go to 2 piece front rotors based on the technical benefits they provide over stock OEM rotors. I looked at the various brands of 2 piece rotors but was inclined toward GiroDisc due to having a set on my former 2004 GT3 car. On that car, they performed well, resisted fade at the track and the complete set was 12.5 lbs. lighter than stock. In. addition, the were are reusable...when it is time for brake rotor replacement, you can order the rotors separately for only 40% of the price of a complete set of rotors with hats. For the 991.2 GTS, simply replace the existing caliper bolts with new OEM caliper bolts The GiroDisc bolt right up. Detailed technical data is found at https://girodisc.com/technical-info/ In the case that your specific Porsche model requires extended caliper bolts and spacers, such as a 991.1 GTS, they are included at no charge.
Having sold myself on the benefits of 2 piece rotors over OEM and aftermarket 1 piece slotted, drilled or both, and knowing that Porsche doesn't make OEM 2 piece rotors for my car, I needed to look elsewhere. Overall, the alternative 2 piece rotors out there, based on my prior experience with GiroDisc and their excellent reputation for quality products and product support, I decided on GiroDisc. In doing my research, I discovered an exemplary source for GiroDisc and other misc. parts, Clark Hamerly (chamerly@apexperformance.net). He priced out the GiroDisc front rotors for me, and told me I could have a set delivered in less than a week. These rotors are 2X more than stock at $1,300 an axle. So in effect I would have to to cough up about $600 more VS stock for a set of GiroDisc front rotors. Why would I do this? Isn't a brake rotor a generic term? Not the case when you compare 1 piece stock and aftermarket rotors to 2 piece GiroDisc rotors and the exclusive benefits they provide (Detailed on the GiroDisc website.).
I estimate a set of GiroDisc rotors will last at least 20,000 miles...I drive about 4,000 or fewer miles per years, it would be 5 years before the GiroDisc rotors needed replacement. So I was in effect, spreading the additional cost GiroDisc rotors over stock, over 5+ years. But when it comes time for GiroDisc rotor replacement, there is no need to buy new hats with the rotors as the hats are reusable. Now when it comes time for rotor replacement, only plop down $850 and you are sent new front or rear GiroDisc rotors, and can reuse the old hats. Simply remove the worn GiroDisc rotors from the car, unbolt the worn out rotors from their hats, and bolt up the new GiroDisc replacement rotors to the "old" hats.
Lastly, the GiroDisc rotors just look like they belong on my car. They are state of the art compared to ole school drilled rotors with their proclivity to crack under extreme conditions. GiroDisc rotors run cooler...and that's just plain cool.
Our AP Racing by Essex Brake Kits have been mentioned numerous times in this thread, and I wanted to let everyone know that we are about to launch our largest sale ever, including our 380mm front and rear brake systems for the 991. You will be able to save up to $1,000 on some of our 991 brake kits during this sale. The sale runs from November 1st-30th. Our website will reflect the sale prices starting November 1st.
As an example, click this link to see the full menu of options for a 991.1 C2S here. Enter your year/make/model at the top of our site for your car's specific options: https://www.essexparts.com/my-vehicl...0S/Iron%20disc
Our 2-piece J Hook discs will also be on sale! \
__________________
'09 Carrera 2S, '08 Boxster LE (orange), '91 Acura NSX, Tesla Model 3 Performance, Fiesta ST
Jeff Ritter
Mgr. High Performance Division, Essex Parts Services Essex Designed AP Racing Radi-CAL Competition Brake Kits & 2-piece J Hook Discs Ferodo Racing Brake Pads Spiegler Stainless Steel Brake Lines
704-824-6030 jeff.ritter@essexparts.com
Great post, lots of great information that’s helping me decide what to do. I’m actually considering changing 991.1 C2S rotors from stock 340x34 front and 330x28 rears to a 350x34 front and maybe leave the 330 rear if I can get 2 price rotors. Couple of questions I hope someone can answer please. I saw the pics of 350x34 sebro rotor and 350x28, how much do those weight?
I’m also considering doing the 997.1 turbo rotor from rennline 350x34 front SKU#: CS-107. Has anyone tried those with the gt3 pads? Rennline thinks they will not work on my car because it’s from a different model car than mine but as shown in this thread, it worked with many other manufacturers rotors. It seems like a good 2 price rotor at 900$ for front 2 price rotors.
If the weight difference isn’t a lot I might go with the sebros. Seem like a good economical option. I’m just trying to take weight out and not add any if I can while increasing the size of the brakes. Thanks.
Last edited by VelocitasAngelus; 11-22-2023 at 09:57 PM.
my 991.1 4S is factory equipped with PCCBs (350mm front & rear), is it possible to upgrade to 991 GT3/Turbo PCCBs (410mm front & 390mm rear) while keeping stock callipers?
All inputs are appreciated.
Hey y'all happy turkey day.
Read all 9 pages and unless i missed something this is all on a C2S and GTS models. Does anyone know if there is anything that can be done with 4 piston C2/C4? Can i get a larger rotor, keep my calipers and get slightly larger pads?
991.1 C2
01-15-2023, 12:15 AM
GiroDisc, the solution?
