2 piece aftermarket rotors - better cooling

m4forum · 09-03-2020, 04:44 AM

I dont need the bite of DS3.12 is too much pad for what I am looking for. I will get something with lower bit and longer live ... seems like Ferodo doesnt have the option. I will try Raybestos ST43.

HP Autosport · 09-03-2020, 07:02 PM

Quote:

Originally Posted by m4forum

I am fighting brake overheating on M4 at Watkins Glen and Grattan. After 15min start to lose confidence on brakes. My rotor temps are 1400F. Crazy !!!!
Cooling ducts on front and rear but it doesn't resolve the issue.
I know some people go with BBK but I am not planning to send 10k. It doesn't make sense if should have a more affordable solution.
I am looking into Girodisc and they seem to have good design, 2 piece, much more vents (could not count). Just wonder if somebody has some experience with girodisc or even StopTech rotors and their thermal performance in comparison with OE rotors.

Stoptech ARK is a good choice if you are already using cooling ducts. What track pad are you currently using? Are you getting pad fade or boiling your brake fluid?

Alcon is another choice if you are looking for both front and rear rotors. Alcon is about 60% more cost-wise though.

m4forum · 09-03-2020, 08:58 PM

using Ferodo 3.12 but they dont last. already cooling. Alcon is very expensive and have not seem much information that supports it ... to be honest for all aftermarket rotors didn't see any evidence (real data) they can reduce brake temp

M3SQRD · 09-05-2020, 10:58 AM

Quote:

Originally Posted by m4forum

using Ferodo 3.12 but they dont last. already cooling. Alcon is very expensive and have not seem much information that supports it ... to be honest for all aftermarket rotors didn't see any evidence (real data) they can reduce brake temp

Alcon rotors have more cooling vanes so they’re able to pump more air thru the rotor compared to the OEM rotor. There’s also no restriction to the vanes at the ID of the rotor ring whereas, although it’s a much improved design over e9x M3 OEM rotors, the F8x rotors have restrictions due to the rotor mounting pins cast in Alum bosses. What data are you looking for? It’s basic engineering principles.

HP Autosport · 09-05-2020, 12:41 PM

Quote:

Originally Posted by m4forum

using Ferodo 3.12 but they dont last. already cooling. Alcon is very expensive and have not seem much information that supports it ... to be honest for all aftermarket rotors didn't see any evidence (real data) they can reduce brake temp

You will get longer pad life from Ferodo DS1.11 and just give up a little on friction level.

A few people running the Alcon don't seem to be on the forums. In addition, the price drives away people to the Stoptech ARK or just a proper front BBK.

m4forum · 09-08-2020, 09:49 PM

Quote:

Originally Posted by M3SQRD

Alcon rotors have more cooling vanes so they’re able to pump more air thru the rotor compared to the OEM rotor. There’s also no restriction to the vanes at the ID of the rotor ring whereas, although it’s a much improved design over e9x M3 OEM rotors, the F8x rotors have restrictions due to the rotor mounting pins cast in Alum bosses. What data are you looking for? It’s basic engineering principles.

Thanks for the feedback. I am looking for test data. In theory more vanes means more surface area what means better cooling but how much more. 5% better cooling doesnt have significant impact but 80% does have impact. I am really surprised the lack of data the aftermarket industry has seems like everything is only based on theory. An OEM spent $$$$ testing after all their design and virtual testing is complete and still get failures which are fixed with more design work.

I need to replace my rotors anyway and will be running some comparison test most likely next year. Not sure yet which solution Alcon or EBC. RB and Stoptech wont be considered due their lack of support.

HP Autosport · 09-09-2020, 11:03 AM

Quote:

Originally Posted by m4forum

Thanks for the feedback. I am looking for test data. In theory more vanes means more surface area what means better cooling but how much more. 5% better cooling doesnt have significant impact but 80% does have impact. I am really surprised the lack of data the aftermarket industry has seems like everything is only based on theory. An OEM spent $$$$ testing after all their design and virtual testing is complete and still get failures which are fixed with more design work.

I need to replace my rotors anyway and will be running some comparison test most likely next year. Not sure yet which solution Alcon or EBC. RB and Stoptech wont be considered due their lack of support.

Remember OE also wants to keep cost down so the least expensive rotor that passes "their test" will be used.

m4forum · 09-09-2020, 07:43 PM

The same for aftermarket which so far I have not seem a simple piece of data. On OE case they must meet minimal specification by law.

3MOS · 09-11-2020, 12:50 AM

+1 for the RB rotors even though it seems you've written them off. I'm not sure you can go wrong here - all of your options seem to be an improvement over the stock rotors.

I ended up purchasing pads from KNS Brakes - thought their sales/support team was very good, so I'd suggest you give them a call.

flojo09099 · 10-14-2020, 12:01 AM

Just bought a F82 M4 with cracked front rotors and looking for aftermarket options as well. Has anyone heard of Paragon Brakes? Couldn’t find any reviews about them. Lower cost than Girodisc/Racing Brake, and the specs seem great too. Any feedback would be greatly appreciated!

adam996GT3 · 08-30-2021, 10:05 AM

Quote:

Originally Posted by m4forum

Quote:

Originally Posted by M3SQRD

Alcon rotors have more cooling vanes so they’re able to pump more air thru the rotor compared to the OEM rotor. There’s also no restriction to the vanes at the ID of the rotor ring whereas, although it’s a much improved design over e9x M3 OEM rotors, the F8x rotors have restrictions due to the rotor mounting pins cast in Alum bosses. What data are you looking for? It’s basic engineering principles.

Thanks for the feedback. I am looking for test data. In theory more vanes means more surface area what means better cooling but how much more. 5% better cooling doesnt have significant impact but 80% does have impact. I am really surprised the lack of data the aftermarket industry has seems like everything is only based on theory. An OEM spent $$$$ testing after all their design and virtual testing is complete and still get failures which are fixed with more design work.

I need to replace my rotors anyway and will be running some comparison test most likely next year. Not sure yet which solution Alcon or EBC. RB and Stoptech wont be considered due their lack of support.

Wondering if you replaced your rotors to a 2 piece design and what your thoughts are?

m4forum · 08-30-2021, 11:57 AM

I end up upgrading my calipers in order to resolve the overheating issue. I am not sure the issue you are trying to resolve but after lot of discussion some suppliers and specialists the recommendation to fix overheating is always a brake system with higher thermal capacity AND higher heat dissipation properties.
I am using girodisc on rear and so far I like them .... but they are working with gold rear calipers.

09-03-2020, 04:44 AM	#23
m4forum First Lieutenant 76 Rep 348 Posts Drives: M3 Join Date: Oct 2015 Location: Michigan iTrader: (6)	I dont need the bite of DS3.12 is too much pad for what I am looking for. I will get something with lower bit and longer live ... seems like Ferodo doesnt have the option. I will try Raybestos ST43.
	Appreciate 0 Quote

09-03-2020, 08:58 PM	#25
m4forum First Lieutenant 76 Rep 348 Posts Drives: M3 Join Date: Oct 2015 Location: Michigan iTrader: (6)	using Ferodo 3.12 but they dont last. already cooling. Alcon is very expensive and have not seem much information that supports it ... to be honest for all aftermarket rotors didn't see any evidence (real data) they can reduce brake temp
	Appreciate 0 Quote

09-09-2020, 07:43 PM	#30
m4forum First Lieutenant 76 Rep 348 Posts Drives: M3 Join Date: Oct 2015 Location: Michigan iTrader: (6)	The same for aftermarket which so far I have not seem a simple piece of data. On OE case they must meet minimal specification by law.
	Appreciate 0 Quote

09-11-2020, 12:50 AM	#31
3MOS Enlisted Member 8 Rep 34 Posts Drives: ... Join Date: Jan 2018 Location: By the Bay iTrader: (0)	+1 for the RB rotors even though it seems you've written them off. I'm not sure you can go wrong here - all of your options seem to be an improvement over the stock rotors. I ended up purchasing pads from KNS Brakes - thought their sales/support team was very good, so I'd suggest you give them a call.
	Appreciate 0 Quote

10-14-2020, 12:01 AM	#32
flojo09099 Registered 0 Rep 1 Posts Drives: F82 M4 Join Date: Oct 2020 Location: FL iTrader: (0)	Just bought a F82 M4 with cracked front rotors and looking for aftermarket options as well. Has anyone heard of Paragon Brakes? Couldn’t find any reviews about them. Lower cost than Girodisc/Racing Brake, and the specs seem great too. Any feedback would be greatly appreciated!
	Appreciate 0 Quote

08-30-2021, 11:57 AM	#34
m4forum First Lieutenant 76 Rep 348 Posts Drives: M3 Join Date: Oct 2015 Location: Michigan iTrader: (6)	I end up upgrading my calipers in order to resolve the overheating issue. I am not sure the issue you are trying to resolve but after lot of discussion some suppliers and specialists the recommendation to fix overheating is always a brake system with higher thermal capacity AND higher heat dissipation properties. I am using girodisc on rear and so far I like them .... but they are working with gold rear calipers.
	Appreciate 0 Quote