Which drilled slotted rotors?

[Martin Schacht]

Thanks to one and all for responding to my post. I do track the car. The cars has 2,200 miles and 3 days at the track. When I got a 2004 Porsche GT3, the first thing I did was to swap out the PCCB rotors with iron, went to GIRO 2 piece front and SEBRO aftermarket (Cheap) slotted on the rear. Also ran Pagid RS 29 Yellows all the way around, never a problem. List price for replacement PCCB rotors, about $21,000. And BTW, the 2020 Mustang Performance Package 1 front rotors are bigger in dia. than the 350mm fronts on my former GT3. It also had 350mm rears. On the other hand, the GT3 was 700 Lbs lighter than the 2020 Mustang GT.

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[Martin Schacht]

The price difference is probably two piece versus one piece designs.

I have to agree....that makes perfect sense. All I know is that I had GIRO 2 piece in the past, and worked nicely. no trouble after 2 years on the track on a 2004 Porsche GT3.

 

[Martin Schacht]

Floating rotors consist of two pieces: one central hub (sometimes called “the hat”) that attaches to the wheel itself, and an outer rotor ring that makes contact with the brake pad upon braking. ... This setup allows the rotor ring to move slightly as needed to optimize contact with the brake pad, or to “float.”

I had had GIRO "Floating" rotors on my former track car, a 2004 Porsche GT3. Never had a single problem, had them on for 1 1/2 years, at least 10 track events, flawless, no fade, ever.

I am headed to the desert, Chuckwalla Valley raceway, in early may. It is guaranteed to be hot, and I don't want to experience overheating in the brake department. In has been my recent experience, at a HPDE/DE, the 380mm Mustang GT PP1 front rotors got hot and became less efficient as the session progressed. What could I do to remedy the situation? I had already had the system flushed with Motul 600 DOT 4 brake fluid. In retrospect, I should have gone to Motul 660, next time. Another cooling trick I will be trying, install 1mm titanium shims between the caliper and the pads, will route incremental air to the calipers, and am trying out the Vorshlag bolt on air deflectors, 3X the size of stock. Just to be certain I have done absolutely everything I will be installing 2 piece floating rotors. It is claimed they run cooler than stock, have optimally designed veins and slots and are lighter than stock. The down side, the three sets I have looked at cost from $900 to $1,000 for the front. Putting on $1,000 rotors, will need fresh pads.. "What part of racing will be cheap?"

 

[Brian@BMVK]

Floating rotors consist of two pieces: one central hub (sometimes called “the hat”) that attaches to the wheel itself, and an outer rotor ring that makes contact with the brake pad upon braking. ... This setup allows the rotor ring to move slightly as needed to optimize contact with the brake pad, or to “float.”

I had had GIRO "Floating" rotors on my former track car, a 2004 Porsche GT3. Never had a single problem, had them on for 1 1/2 years, at least 10 track events, flawless, no fade, ever.

I am headed to the desert, Chuckwalla Valley raceway, in early may. It is guaranteed to be hot, and I don't want to experience overheating in the brake department. In has been my recent experience, at a HPDE/DE, the 380mm Mustang GT PP1 front rotors got hot and became less efficient as the session progressed. What could I do to remedy the situation? I had already had the system flushed with Motul 600 DOT 4 brake fluid. In retrospect, I should have gone to Motul 660, next time. Another cooling trick I will be trying, install 1mm titanium shims between the caliper and the pads, will route incremental air to the calipers, and am trying out the Vorshlag bolt on air deflectors, 3X the size of stock. Just to be certain I have done absolutely everything I will be installing 2 piece floating rotors. It is claimed they run cooler than stock, have optimally designed veins and slots and are lighter than stock. The down side, the three sets I have looked at cost from $900 to $1,000 for the front. Putting on $1,000 rotors, will need fresh pads.. "What part of racing will be cheap?"

1. Upgrade pads to higher friction/torque one that also has higher temp capability. They can do the same work over less time.

2. Vorshlag upgraded cooling deflectors

The OEM design rotor already has proper design for cooling and just needs more air. Yes, a 2 pc will be lighter and will keep the hat from getting as warm, but it's still an iron friction ring.

 

[Martin Schacht]

1. Upgrade pads to higher friction/torque one that also has higher temp capability. They can do the same work over less time.

2. Vorshlag upgraded cooling deflectors

The OEM design rotor already has proper design for cooling and just needs more air. Yes, a 2 pc will be lighter and will keep the hat from getting as warm, but it's still an iron friction ring.

Being a new Mustang owner, coming from 20+ years of Porsche, I have so much to learn, and I don't have time to go down dead end trails as I seek to optimize my car for the track, HPDE/TT. I have already made some mistakes, albeit minor thankfully, in my quest to get as prepared as possible for the track. To shortcut the process, I got in touch with Brian ([email protected]) to to get his opinion. I subscribed to his services and was super impressed with his track car prep knowledge. I have already incorporated some of his suggestions, and am very, very pleases. He has saved me so much time and money already. I won't quote his rates but they are very reasonable. First round, you are asked to fill out a questionnaire defining your performance goals, and budget. Brian then gets back to you promptly with some options. At that you may decide to take a "deep dive" and commit to the the services he offers.

 

[Nuked]

It has been a few years since I made a purchase, but RotorPros has always been my go to. Lots of Evo track guys ran them with no complaints and the price is good enough that if you want to swap every season it is not cost prohibitive to do so.

 

[Andy13186]

no problems with my baer eradispeed+'s cross drilled and slotted

 

[Martin Schacht]

For the standard Mustang GT rotors, $745 for a 2 piece drilled/slotted rotor isn't bad. But when you have the Performance Package brakes on a 2020 Mustang GT, the Brembo front calipers, now you step up to a new level in price, $995 on American Muscle. Having replaced far too many drilled rotors due to heat induced cracking on former Porsche cars, for me personally, there are but two (2) choices, STOPTECH or GIRO...both are slotted only. I did have one set of GIRO slotted rotors on a 2004 Porsche GT3, they worked well and wore well too.

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[luc]

I’m very cheap, centric blank $46 and I have been racing for 30 years so kind of fast.... right Martin?
No issues whatsoever on fast race track. That and good race pads and you are set

https://www.rockauto.com/en/catalog/ford,2017,mustang,5.0l+v8,3424235,brake+&+wheel+hub,rotor,1896
Ford got the braking right on the Pp1 and 2 cars. Great calipers, big 15” rotors, under tray air cooling channel directing air to deflectors mounted on the suspension, not much to improve there save for race pads,,.. now suspension, tires and camber plates are legitimate areas to improve on

 

[EFI]

Lets be serious how many people track their car? If your a track enthusiast you’ll have an entirely different set up for your pads and rotors but for the other 99% quality drilled and slotted rotors will more than exceed your needs.

Lots of people track their car, there's a whole section dedicated to just that. Not many people race professionally or for money, but there are lots of Mustang drivers that take their car on the track.

And drilled rotors do not belong on the track, even Ford themselves went back to plain rotors for the GT350s.

 

[sigintel]

Look into the Baer Eradispeed. I know quite a few people who track with these. They are slotted and cross drilled and you save over 30lbs in rotational mass, over 22lbs just for the front.

I know the consensus is that you track only with full rotors or just slotted. However, tell that to the countless Porsche and BMW M guys that track their cars with OEM brakes that are cross drilled. In fact when I had my 911 guys would switch out their PCCBs and go to the non PCCB rotors and calipers just to save their expensive PCCB rotors. If you get a rock stuck in there they are history and you are out of nearly $10k.

Have seen lots of cracking Porsche rotors at the drills at track days...

 

[Dave2013M3]

Have seen lots of cracking Porsche rotors at the drills at track days...

True but rotors are a replaceable item when tracking, the cracks are normally mild around the holes. Also these are the cars with race pads and r compound tires. A vast majority of people who track their BMWs and PCars don't have issues with the OEM drilled rotors. I know I was one of them, quite a few events at Willow and such and I never cracked my rotors. Although I did my runs on OEM Pirellis and just changed out the pads and fluid before and after each event.

I don't plan on tracking my GT, I want the weight savings of the Eradispeed rotors. If I do a driving event it will probably be at only 8/10s driving and a few laps. Also, with the S550 GT the car will go into limp mode due to tranny or the diffy overheating before you can probably do any damage to the rotors, especially here in Cali where the temps at Willow and other tracks can be well into the 100s on certain days.

 

[Martin Schacht]

The slotted 2 piece rotors are sort of an insurance policy, insurance is never cheap. I ran drilled rotors on cars for years. There were always little hairline cracks. Local track wisdom was such that when the cracks connected from hole to hole, time to consider replacing the rotors, regardless of the thickness of the rotors. Not such a big deal, solid rotors are so cheap, drilled rotors not too far behind. The thing about drilled/cast files in rotors I never appreciated, the holes would fill up in a session or two. I was too lazy to drill out the crud in the holes. With slotted rotors, they are good until the slots are fading away, or so I am told. Manufacturers of slotted rotors claim not only are they lighter, they run cooler. For the cooler portion...this is the reason I am inclined to make the investment in slotted rotors over drilled. But then, what the hell do I know.

 

[Dave2013M3]

The slotted 2 piece rotors are sort of an insurance policy, insurance is never cheap. I ran drilled rotors on cars for years. There were always little hairline cracks. Local track wisdom was such that when the cracks connected from hole to hole, time to consider replacing the rotors, regardless of the thickness of the rotors. Not such a big deal, solid rotors are so cheap, drilled rotors not too far behind. The thing about drilled/cast files in rotors I never appreciated, the holes would fill up in a session or two. I was too lazy to drill out the crud in the holes. With slotted rotors, they are good until the slots are fading away, or so I am told. Manufacturers of slotted rotors claim not only are they lighter, they run cooler. For the cooler portion...this is the reason I am inclined to make the investment in slotted rotors over drilled. But then, what the hell do I know.

I don't disagree with you at all, its just people make it sound like a well built quality cross drilled rotor will self destruct the first time you take in out on the track. My experience differs with my BMWs and Porsches. The funny thing is I can't even afford to take my car to the track now. Two kids one in college, although the Army is helping him pay, there is still ancillary costs associated with this as any parent knows who has kids in college.

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