[mcvaughan]

18x10 ET33 is the sweet spot. TA16 on 275/35 with a 12.5 spacer. No rub, no hassle.

[Karmic Man]

Originally Posted by GreenLightGo

I just got back from two days at Watkins Glen, and here is an update on my track setup:

I put on fresh Cup2's in sizes 265/30-19 front, and 295/30-19 rear. No problems with rubbing, even under compression when hitting the bus stop curbing at 90 mph. This tire setup is ideal, imo. With the engine tune and suspension upgrades, the stock tire sizes were just not up to the task. You had to be careful rolling on to the throttle out of corners, or you would slide the rear. The wider rubber is a perfect complement to the increased HP and torque. The car tracked well into corners, with no understeer, and the rear end stuck like glue when you got on the throttle at the apex. It was an amazing difference. I am sold on this setup. I might try the Troffeos, but I have no issues with the Cup2's, so I'm not looking to make a change in that dept right now.

Now the bad news--my rotors warped after my third session on day 2. These are original stock rotors, with endless MX-72 pads. They have 11 track days on them, and 8,700 total miles. I don't know if warping is partially due to the wear on the rotors, or if the stock rotor just got too hot on my last session. The increased power, more aggressive rubber and stronger brake pads could be combining to push the stock rotors beyond their design limits. It seems like my options are to put new stock rotors on and see how long they last, or go with an aftermarket rotor designed for track use. Another option is finding a way to redirect the cooling air from the inlet in the wheel well so that it blows directly on the brakes.

I would love any feedback you have on a good rotor/brake solution. Thanks!

I bet it’s the pads and not the rotors

MX72 is not sufficient for a heavy car shod with wide R tyres

Many serious trackers and racers had great results with the ME20, ME22 or at a minimum, CC-Rg.

The new N39S is a further development from Endless so my suggestion is to try them out

https://www.trackdayforum.com/index....chfolger-me22/

[GreenLightGo]

Originally Posted by VisualEcho

SHOW ME!!!





I second the fact that the rotors aren't warped, but merely have pad deposits. If you have a shop nearby that will turn them just slightly without removing much material, you can usually get it done for $12 a rotor, which is what I do. And yes, even if they have holes they can be turned.

Thanks for the feedback, everyone. I will try getting the rotors turned to see if pad deposits are the issue. In the meantime, I ordered Girodisc rotors for the front. They are backordered and are several weeks out, so I'll see if the rotor turning solves the braking vibration in the meantime. The Girodisc rotors are a big spend initially ($1,300), but after that you can just replace the rings for $800 a pair. OEM rotors are $600 per pair, so after the initial investment the Girodisc isn't a huge premium over the cost of OEM. And you get slotted rotors instead of drilled, which is preferable for track use anyway. They are a true floating rotor system, instead of the M2C's semi-floating rotors.

I'll post pics of the tires, as requested.

[chief1richard]

Originally Posted by GreenLightGo

Thanks for the feedback, everyone. I will try getting the rotors turned to see if pad deposits are the issue. In the meantime, I ordered Girodisc rotors for the front. They are backordered and are several weeks out, so I'll see if the rotor turning solves the braking vibration in the meantime. The Girodisc rotors are a big spend initially ($1,300), but after that you can just replace the rings for $800 a pair. OEM rotors are $600 per pair, so after the initial investment the Girodisc isn't a huge premium over the cost of OEM. And you get slotted rotors instead of drilled, which is preferable for track use anyway. They are a true floating rotor system, instead of the M2C's semi-floating rotors.

I'll post pics of the tires, as requested.

Good luck trying to find anyone who turns rotors. You'll have a better chance of finding a Blue Lobster in Boston Harbor. I spent much time going to specialty shops and even truck repair shops. Some shops said they would do it, but all called back later and said the Rotors are "too thick" for their machines. Your best bet will be a Machine Shop, and That will probably outweigh cost of a new set.

[GreenLightGo]

Originally Posted by VisualEcho

SHOW ME!!!





I second the fact that the rotors aren't warped, but merely have pad deposits. If you have a shop nearby that will turn them just slightly without removing much material, you can usually get it done for $12 a rotor, which is what I do. And yes, even if they have holes they can be turned.

Here are pics of the 265/30-19 fronts and 195/30-19 rears, mounted on OZ Hyper GT wheels.

[GreenLightGo]

Originally Posted by Karmic Man

I bet it’s the pads and not the rotors

MX72 is not sufficient for a heavy car shod with wide R tyres

Many serious trackers and racers had great results with the ME20, ME22 or at a minimum, CC-Rg.

The new N39S is a further development from Endless so my suggestion is to try them out

https://www.trackdayforum.com/index....chfolger-me22/

Thanks, Karmic. I will experiment with different pads. The MX-72's were recommended by another M2 driver at the track, and have held up well. I'll see what Girodisc recommends as a good combo with their rotors. Unfortunately, there is no such thing as a pad that is great for both street and track. The MX-72's have been a good hybrid pad. Better than the stock pads on the track, but still quiet and plenty of cold bite on the street. I think the Ferodo DS2500's are in the same category. I am not interested in swapping between track and street pads, so whatever I choose is what I'm going to live with, and I understand there will be a tradeoff. If I can find a track pad that doesn't require a lot of heat in them before they work on the street, I will go with that. The quest continues...

[VisualEcho]

Originally Posted by GreenLightGo

Here are pics of the 265/30-19 fronts and 295/30-19 rears, mounted on OZ Hyper GT wheels.

Looks great man!

M3R1

[Karmic Man]

Originally Posted by GreenLightGo

Thanks, Karmic. I will experiment with different pads. The MX-72's were recommended by another M2 driver at the track, and have held up well. I'll see what Girodisc recommends as a good combo with their rotors. Unfortunately, there is no such thing as a pad that is great for both street and track. The MX-72's have been a good hybrid pad. Better than the stock pads on the track, but still quiet and plenty of cold bite on the street. I think the Ferodo DS2500's are in the same category. I am not interested in swapping between track and street pads, so whatever I choose is what I'm going to live with, and I understand there will be a tradeoff. If I can find a track pad that doesn't require a lot of heat in them before they work on the street, I will go with that. The quest continues...

No worries...the Endless N39S has good bite in cold temp so it will be ideal for street use as well

Out of curiosity, what's the width and offset of your wheels?

[GreenLightGo]

For the OZ Hyper GT, I'm using 19x9 in the front, and 19x10 in the rear, with the stock offsets. No spacers needed. I originally bought them for the stock tire sizes, but the new rubber fits them fine. I like the tire bulge, it protects the wheels if they tip over on their face when changing them (that happened to two of my stock wheels, which caused cosmetic damage to the wheels).

BTW, here's an interesting article on the myth of warped brake rotors:

https://alconkits.com/support/brake-...d-brake-rotors

[VisualEcho]

Originally Posted by GreenLightGo

BTW, here's an interesting article on the myth of warped brake rotors:

https://alconkits.com/support/brake-...d-brake-rotors

Great link.

The only thing no aftermarket company has ever been able to explain is why you don't have to bed-in brakes on ANY new car, yet it's super rare that they suffer from pad deposits regardless of how easy you drive them, or in what conditions. And if you drive your car to 80K, then buy OEM NEW pads and rotors, and don't bed them in or drive them too easily, you absolutely run the risk of pad deposits.

Things that make you go hmmm...