6 piston vs 4 piston with fixed rotor design

[Walt]

I'm debating between upgrading to the 6 pistons or get rotors from a 2022+ model for my 4 pistons, that are apparently fixed by having the cooling veins on the proper side.

Is the extra weight and rotational inertia worth it for the 6 pistons (on an Ecoboost model)? I'm planning to combine either with a JLT brake hose kit for cooling.

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[Angrey]

Only you can answer that. Nearly all modern cars are traction limited, meaning you have more than enough braking capacity to lock up the tires. Additional size from that point is for effectiveness in repeated use. The bigger the swept area, the more fade resistance you'll have.

Are you running out of brakes?

 

[Walt]

Only you can answer that. Nearly all modern cars are traction limited, meaning you have more than enough braking capacity to lock up the tires. Additional size from that point is for effectiveness in repeated use. The bigger the swept area, the more fade resistance you'll have.

Are you running out of brakes?

Yes it's mainly for the cooling issue that I was planning to upgrade. My stock pads and rotors were completely destoryed after my first proper track day and I was experiencing fade. While thinking about replacing everything with better pads, I was wondering if the 6 pistons would be worth the extra weight instead of trying to source rotors with the proper cooling veins. The added cost of the upgrade is not that much more with remanufactured calipers from rockauto I'm mostly concerned about the added rotational mass

 

[shogun32]

I'm planning to combine either with a JLT brake hose kit for cooling.

ick, why not just mod the belly pan and get some air deflectors?

 

[Walt]

ick, why not just mod the belly pan and get some air deflectors?

Technical inspection here is very strict and something like that will red flag my car, so I'd have to buy a second belly pan which is shipped to me as expensive as the brake hoses kit. I'd have to remove the hoses as well too for the inspection. Only downside is that the foglights in EU are actually the day running lights so I'd be losing those...

Best option would be the GT belly pan but that requires the PP splitter as well which is very expensive.

I'm also not allowed to change ANYTHING about the brakes, not even stainless steel braided hoses. I'm hoping to get away with the 6 pistons because they come stock on the GT and look OEM, they most likely won't notice.

 

[shogun32]

I'm also not allowed to change ANYTHING about the brakes,

you guys need another 'tractor mob with natural fertilizer dispensers' to ring your auto rule making agencies.

 

[Walt]

you guys need another 'tractor mob with natural fertilizer dispensers' to ring your auto rule making agencies.

Haha yeah I'll bring up the idea plenty of farmers in the area, surely you guys don't want stainless steel hoses on your tractors?

 

[Buldawg76]

How did you determine that 22+ 4 piston rotors have the cooling veins swapped to the inside of rotor hat versus being on the outside for pre 22 models. I am slowly gathering the parts to do the 4 piston GT swap but have not sourced front rotors yet so would like to be sure the 22+ rotors truly have the rotor hat swapped to put the airflow to veins on the inside of hat versus the outside like pre 22 GTs have.

BD

 

[shogun32]

How did you determine that 22+ 4 piston rotors have the cooling veins swapped to the inside of rotor hat versus being on the outside for pre 22 models.

saw it with my own eyes. The cutover was approx March '21.

Wait, so you have the 2-piston brakes today? Then I would just jump to the 6-pots. Or have you confirmed there are useful pad compounds for the 4-pots? Check KNSbrakes for options. Unless you're just street driving.

 

[Walt]

How did you determine that 22+ 4 piston rotors have the cooling veins swapped to the inside of rotor hat versus being on the outside for pre 22 models. I am slowly gathering the parts to do the 4 piston GT swap but have not sourced front rotors yet so would like to be sure the 22+ rotors truly have the rotor hat swapped to put the airflow to veins on the inside of hat versus the outside like pre 22 GTs have.

BD

https://www.opmustang.com/blog/2015...-brake-rotor-for-ecoboost-and-non-brembo-gt#/

 

[MAGS1]

How did you determine that 22+ 4 piston rotors have the cooling veins swapped to the inside of rotor hat versus being on the outside for pre 22 models. I am slowly gathering the parts to do the 4 piston GT swap but have not sourced front rotors yet so would like to be sure the 22+ rotors truly have the rotor hat swapped to put the airflow to veins on the inside of hat versus the outside like pre 22 GTs have.

BD

To my knowledge they don’t sell the “wrong” ones anymore. The ones I’ve seen for sale have the veins in the correct orientation. I have a 2022 GT and can confirm they are in the correct orientation now. As Matt said, sometime in 2021 it was changed.

 

[Buldawg76]

saw it with my own eyes. The cutover was approx March '21.

Wait, so you have the 2-piston brakes today? Then I would just jump to the 6-pots. Or have you confirmed there are useful pad compounds for the 4-pots? Check KNSbrakes for options. Unless you're just street driving.

Thanks @shogun32 for your visual confirmation. I was not aware of the change, @Walt, Thanks for the link as well for more clarification as well as part numbers.

I assume the 2nd portion of this post is for Walt concerning his brakes on the car he is tracking with now.

If not I already have sourced a complete set of 4 piston front and rear GT calipers with pads and lines for my premium eco with the base 2 piston calipers. I got some rockauto wholesale rear rotors and pad kit for under 70 bucks as well, so just need front rotors to complete the parts for the swap.

I don't track my car as of yet but may in the future so might as well get the upgraded front rotors since they are readily available.

Thanks all for the valuable info.

BD

 

[TrueBlue22]

Have the 6-piston Bremos on my 2022 HPP. Can confirm they will give you a concussion if you dare use their full braking power. Total overkill for the street.

 

[GrabberBargeCaptain]

How do the 4 piston stock GT calipers fare on track with just a pad and fluid upgrade I wonder?

@TrueBlue22 I absolutely believe it. "Even" the 4 piston calipers (every car i've ever owned only has 1 or 2 pistons) will put your head through the windshield with ease.

 

[TrueBlue22]

How do the 4 piston stock GT calipers fare on track with just a pad and fluid upgrade I wonder?

@TrueBlue22 I absolutely believe it. "Even" the 4 piston calipers (every car i've ever owned only has 1 or 2 pistons) will put your head through the windshield with ease.

Oh yeah. Between the 200+ less pounds over the front wheels and the 6-piston Brembos with manhole-sized rotors, the HPP has way more braking than you will ever need short of a track day. I suppose that’s not the worst thing to have on the street!

Also, the Brembos are super-cranky when cold. Loud grunts and groans until some heat builds up in the rotors, which takes some time due to the aggressive venting and brake cooling ramps in the underbelly tray.

The stoping power is unbelievable.

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