2016 GT4 Rotor Suggestions

[NickG]

So I may be opening up Pandora's box here, as I appreciate everyone has their preferences of brakes and rotors, but here goes.

I run my GT4 about 12-14 days/year at HPDE events (as Instructor). I bought car in 2022 and it came with OEM rotors and Ferodo Racing pads (FCP4664GB/5GB front/rear). No fade. No squeal. Reasonable braking capacity. I run Pilot 4Ss (although have a set of Cup 2s to try out next season to determine wear rates). I have a new set of Ferodo rotors to put on front and rear this winter. Any suggestions beyond OEM rotors to pair up with them for similar/better performance?

Thanks.
Nick

[blueline]

So I may be opening up Pandora's box here, as I appreciate everyone has their preferences of brakes and rotors, but here goes.

I run my GT4 about 12-14 days/year at HPDE events (as Instructor). I bought car in 2022 and it came with OEM rotors and Ferodo Racing pads (FCP4664GB/5GB front/rear). No fade. No squeal. Reasonable braking capacity. I run Pilot 4Ss (although have a set of Cup 2s to try out next season to determine wear rates). I have a new set of Ferodo rotors to put on front and rear this winter. Any suggestions beyond OEM rotors to pair up with them for similar/better performance?

Thanks.
Nick

No Pandora's box at Carpokes! Ask away as there are many good thoughts and opinions on the question.

I prefer AP Racing Competition J-Hook slotted. They are not cheap but the performance when paired with Ferodo DS3.12 pads is unbelievable.

A couple of my posts here:
viewtopic.php?t=2398#p26019
viewtopic.php?t=2398#p26178

Some ideas from Willy & J-Dub:
viewtopic.php?t=2588

Several at Carpokes like Girodisc, so that's a good option. I'd advise almost anything over OEM rotors for hard track-day driving. The OEM's wear out like butter. (Plus I don't like cross-drilled rotors under any circumstances - in my opinion they are a bit gimmicky and they can lead to premature cracking.)

You can find more good discussion on the subject elsewhere at Carpokes. Can easily search individual sub-forums such as the '718 Boxsters & Caymans' and 'Racing' subs. Try "Ferodo", "rotors", "brakes" or whatever other search terms that that might fit your criteria.

[J-Dub]

At the track last Saturday I was talking to a guy with a GT4 in my run group, he has Giro Discs on his car. He said he loved them and would recommend them to anyone. He also had put them on his previous Cayman, a 981.

I am targeting Giro Discs in the future after my factory rotors are all used up but do like how there are many options out there. I bet AP, Giro, PFC, StopTech etc all would be good.

https://www.brrperformance.com/porsche- ... pgrade-it/

[blueline]

At the track last Saturday I was talking to a guy with a GT4 in my run group, he has Giro Discs on his car. He said he loved them and would recommend them to anyone. He also had put them on his previous Cayman, a 981.

I am targeting Giro Discs in the future after my factory rotors are all used up but do like how there are many options out there. I bet AP, Giro, PFC, StopTech etc all would be good.

https://www.brrperformance.com/porsche- ... pgrade-it/

AP Racing has the history going back to 1920 and are heavily associated with pro racing. (AP Racing has been a part of Brembo since 2000). AP's rotors are not cheap but they are quite awesome.

Having said that, I doubt there would be much difference with other higher-end products such as Giro Disc.

An older thread post with a bit more AP Racing info and links: viewtopic.php?p=25025&hilit=ap+racing+rotors#p24873

[NickG]

Thanks everyone for your suggestions. I will probably go with the Girodisc, which sounds like a good choice and not quite as pricey as the APs. You get what you pay for, right!

Has anyone come across pictures showing discs "wear" rate where the normal, minute cracks across the disc finally get a little wider/deeper (still on minute scale). It would be helpful for track folks to gain that knowledge. I can certainly do a before and after with mine, but having a few examples would help, together with maybe number of track days and duration?

Cheers,
Nick

[J-Dub]

IMG_5256.jpeg (3.99 MiB) Viewed 3803 times

Nick,
I had a hard time getting these to show well in the picture but here is one of my rear rotors right now. Note that I am not in a hurry to change these yet but am keeping on eye on them.

[NickG]

20240129_125023[1].jpg (1.77 MiB) Viewed 3766 times

20240129_125111[1].jpg (1.68 MiB) Viewed 3766 times

Thanks for the pic. I can see quite clearly, the cracks emanating from the holes.

Here a couple of shots of my front rotors. They are GiroDiscs. I ordered another set of replacements rim discs and I will just remove the caps from the old discs and put the new (outer) rim discs on. Cost was $1000/pair.

Nick

[blueline]

@NickG

Been meaning to get the pics and data together for you Nick, so after a bit of a delay, here goes.

First pic is of one of my 2021 GT4's factory rotors (front) taken in May 2022 after approx 6,200 miles were on the odometer, of which 1,035 were on track using Ferodo DS3.12 pads for all of those track miles. (The Ferodo pads were installed prior to the car's initial track use at approx 2,200 miles on the odometer.)

The front rotors were obviously shot after the 1,035 track miles. In addition, I measured the thickness of the front and rear OEM rotors when new vs the thickness when the photo below was taken. The fronts were already worn to the minimum safe street thickness per Porsche. The rear rotors were mostly ok. However, both the front and rear OEM rotors wore a lot more and a lot faster than I had expected. (For reference, I have roughly 14,400 total miles on the car since I purchased it new. Approx 3,200 of those are track miles. )

GT4 OEM rotors - Copy (Small).jpg (80.1 KiB) Viewed 3756 times

This 2nd pic compares engineering design of the OEM to AP Racing's 2-piece Competition J-Hook rotors. There really is no comparison to OEM - the vane design along with everything else on the AP rotor is vastly superior to OEM and it's apparent when on track. There's a massive increase in airflow, cooling capacity, and durability. The metallurgy has been specifically designed to handle the temps typically seen on track.

GT4 OEM vs AP Racing rotors - Copy (Small).jpg (84.06 KiB) Viewed 3756 times

The 3rd and 4th pics are of the AP Racing rotors front and rear after 2,153 track miles on the AP rotors. (8,050 miles counting street driving on the AP's). All miles using Ferodo DS3.12 pads.

The fronts are showing small crazing but they still have life. As expected, the rears are in better condition.

What's most interesting are the rotors' thicknesses now. AP Racing rotors new are 34mm front and 30mm rear and the wear since has been minimal with the fronts currently at 33.4 mm - 33.6 mm and the rears at 29.6 mm to 29.7 mm. They have a long service life for hard track driving.

GT4 AP Racing front rotors as of 2024-01-29 - Copy (Small).jpg (99.59 KiB) Viewed 3756 times

GT4 AP Racing rear rotors as of 2024-01-29 - Copy (Small).jpg (68.92 KiB) Viewed 3756 times

You'll be very pleased with far superior rotors such as those from Giro Disc or AP Racing.

[J-Dub]

Nice details Tim!

[blueline]

Nice details Tim!

Thank you Jeremy!