GT500 Brake Swapping The R

[Tomster]

What are the rotor weights?

GT350 weight plus a boat anchor.

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[Niz55]

Just noticed the rotors have 10 lug holes.

 

[JAJ]

The ABS calibration and bias in the ECU will not match the caliper and rotor size in addition to the traction and slip control when swapping things. It might be fine, but it might not be.

There's a risk there, and it depends entirely on piston sizes. The effective radius of the caliper/pad setup won't be very different from the GT350, so if the pistons are the same size then balance and ABS performance will be largely unaffected.

 

[JAJ]

What are the rotor weights?

Based on the published dimensions, the rotors will probably come in around 35 pounds. Calipers will probably be maybe 2 - 4 pounds heavier - it's hard to tell from a photo, but they're clearly much bigger. The point of having all this weight is to reduce the temperature variation over the course of a lap. In a brake application, the heavier a caliper or rotor is, the lower it's peak temperature. It also cools slower, so the average temperature isn't that different from lighter brakes, but the lower peak temperature means they're less likely to cook the fluid or melt the pads.

BTW, I think @50 Deep is doing this swap to make sure that his wheels will fit over GT500 brakes. He may get a performance benefit, but I think the real purpose is to make sure his 20" rims will clear.

 

[Tomster]

I got the distinct impression that he wasn't going back to stock config when texting with him. I expressed my concerns. All in the name of science he says.......

 

[Epiphany]

Based on the published dimensions, the rotors will probably come in around 35 pounds. Calipers will probably be maybe 2 - 4 pounds heavier - it's hard to tell from a photo, but they're clearly much bigger.

GT500 calipers are 21lbs. GT500 rotors are 43lbs.

Yes, 43 lbs.

 

[Droopy1592]

Jesus

 

[Droopy1592]

Jesus

 

[Droopy1592]

Gotta say it twice

 

[JAJ]

GT500 calipers are 21lbs. GT500 rotors are 43lbs.

Yes, 43 lbs.

Wow. Used ones will be in high demand from people who want to hold down their awnings at track days and other outdoor events.

There is a point in time where carbon ceramic just makes so much more sense. What size are they? 410 x 36?

 

[Stage_3]

Wow, those brakes really are massive!!!
I knew they were huge, but not that huge!!!! Wow. lol

 

[DCShelby]

Ceramics would add at least 10k to the price or more. But yes they should be an option if they really want to chase the GT3RS or the Turbo S 911.

 

[JAJ]

Based on Ford's published data below, the larger GT500 rotors and the larger piston sizes will result in a brake effect increase of around 13% on the front axle, coupled with a longer pedal (if you install them on a GT350) because of the increased volume behind the pistons. The GT500 rear axle has a reduction of around 7% because of the smaller rotor and the wider annulus. Ford's spec sheet also indicates that the pad compound "FM 4446/2" is the same for both vehicles and both axles, so it's not a factor in the calculations of braking effect.

So the GT500 has about 20% more front brake bias than the GT350, which isn't surprising considering the extra weight over the front axle.

GT350 front: 394 mm x 36 mm aluminum hat, Brembo six-piston fixed aluminum calipers, 34 mm/36 mm/38 mm pistons, 785.5 sq. cm. swept area. The rotor annulus (friction face width measured out from the center - essentially the depth of the pad) calculates at 79.5 mm
GT500 front: 420 mm x 40 mm aluminum hat, Brembo six-piston fixed aluminum calipers, 34 mm/38 mm/40 mm pistons, 951.7 sq. cm. swept area - the annulus calculates at 92.5 mm
GT350 rear: 380 mm x 26 mm aluminum hat, Brembo six-piston fixed aluminum calipers, 30 mm/32 mm pistons, 514 sq. cm. swept area - the annulus calculates at 49.5 mm
GT500 rear: 370 mm x 30 mm aluminum hat, Brembo six-piston fixed aluminum calipers, 30 mm/32 mm pistons, 619 sq. cm. swept area - the annulus calculates at 64.5 mm

Data is here: https://media.ford.com/content/dam/fordmedia/North America/US/product/2020/mustang/2020-Mustang-Tech_Specs.pdf

 

[honeybadger]

Wow. Used ones will be in high demand from people who want to hold down their awnings at track days and other outdoor events.

There is a point in time where carbon ceramic just makes so much more sense. What size are they? 410 x 36?

I'm really shocked theres no CCB option on a $100k Mustang tbh. Seems like a miss.

 

[Tomster]

Wow. Used ones will be in high demand from people who want to hold down their awnings at track days and other outdoor events.

There is a point in time where carbon ceramic just makes so much more sense. What size are they? 410 x 36?

That's my plan. Hopefully, there will be large demand and quantity brings down the price point.

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