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Best lightweight rear break rotors (OEM size)

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I am looking to replace the OEM rear break rotors with a lighter pair (slotted or plain only, not drilled) without changing the calipers, just a simple replacement of the rotors itself. My goal is mainly to save weight and a small improvement of braking, but the last one is secondary, my upgraded front brakes do a well enough job on the track.

I found http://www.steeda.com/store/steeda-13-inch-rear-brake-upgrade-kit-for-ford-mustang.html which I will not buy. There is no weight indication and even more, the installation is not what I am looking for. I want only the replace the rotors without doing anyhting on the differential.

I found also those: http://www.girodisc.com/Girodisc-Rear-2pc-Floating-Rotors-for-Boss-302_p_6421.html. Weight reduction for 3.5lb as per the add, not bad but it is a two piece floating rotor and perhaps there is a lighter and better version around.
 

TMSBOSS

Spending my pension on car parts and track fees.
6,231
3,230
Exp. Type
HPDE
Exp. Level
5-10 Years
Illinois
Orange said:
I am looking to replace the OEM rear break rotors with a lighter pair (slotted or plain only, not drilled) without changing the calipers, just a simple replacement of the rotors itself. My goal is mainly to save weight and a small improvement of braking, but the last one is secondary, my upgraded front brakes do a well enough job on the track.

I found http://www.steeda.com/store/steeda-13-inch-rear-brake-upgrade-kit-for-ford-mustang.html which I will not buy. There is no weight indication and even more, the installation is not what I am looking for. I want only the replace the rotors without doing anyhting on the differential.

I found also those: http://www.girodisc.com/Girodisc-Rear-2pc-Floating-Rotors-for-Boss-302_p_6421.html. Weight reduction for 3.5lb as per the add, not bad but it is a two piece floating rotor and perhaps there is a lighter and better version around.

I went with the Girodisc rotors. Lighter, look great
 

TMSBOSS

Spending my pension on car parts and track fees.
6,231
3,230
Exp. Type
HPDE
Exp. Level
5-10 Years
Illinois
Torsion said:
So expensive... worth it?

Not if you are asking my wife. LOL

I replaced both the driveshaft and rear rotors. Power to the rear is noticeably better. Traction from the stop is more of a challenge. So yes, a performance improvement.

There are cheaper solutions.

I have a logic block sometime when it comes to cars. :-[
 
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TMSBOSS said:
Not if you are asking my wife. LOL

There are cheaper solutions.

I have a logic block sometime when it comes to cars. :-[

A perfect +1 ;D

Any other opinions/ideas from anyone than the Girodisc rotors?
 

ArizonaBOSS

Because racecar.
Moderator
8,545
2,376
Arizona, USA
To be honest, the best bang for the buck is just to replace with OEM rear rotors. You can get a pair for $40 or $50 from Roush Overstock on ebay. I run these all day long at the track, I'm still on the factory rears even.

If I were to pick a lightweight rear I would get the Girodisc ones but the cost far outweighs the benefit, IMO.
 

Grant 302

basic and well known psychic
From a heat sink perspective, I'd want the mass of the rotor to be similar to stock. I'd only want weight savings to come from an aluminum hat.
 
129
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ArizonaGT said:
To be honest, the best bang for the buck is just to replace with OEM rear rotors. You can get a pair for $40 or $50 from Roush Overstock on ebay. I run these all day long at the track, I'm still on the factory rears even.

If I were to pick a lightweight rear I would get the Girodisc ones but the cost far outweighs the benefit, IMO.

I absolutley agree with you, but here this description fits also well for me: I have a logic block sometime when it comes to cars ::)


Grant 302 said:
From a heat sink perspective, I'd want the mass of the rotor to be similar to stock. I'd only want weight savings to come from an aluminum hat.

Agree and which is the case with the Girodisc as per my understanding: "The central “hat” section of the disc is made from 6061-T6 aircraft specification aluminum. The disc is made from cast iron, constructed in the USA"
 

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