GiroDisk vs AP Essex

[Craigito]

Went to my first Laguna Seca track day. I had PFC pads installed on my car before the event. Just have the stock M brakes on my 2016 M4. In almost every session I has to pull off early due to brakes fading and very soft pedal.

I am looking at both options of either just a switch to Girodisks vs a full AP essex system. Obviously a big decision in terms of cost.

We do about 4 -5 track days a year. Mostly Fontata and have also done Chuckwalla and likely other tracks nearby in the upcoming years.

My buddy with a 911 GTS just had the Girodisks installed and he raved about them for our Laguna track day.

Im leaning to give the Girodisk setup a try at first. You all know the M4 is pretty heavy and my driving style leads to pretty hard breaking.

So just looking for a little push one way or the other

[stevehifi]

if you only do a couple track days a year then just do the rotors.

you could also do just the front BBK with a better rear rotor to save on cost.

[m4forum]

Brake fading or pedal feeling change is a result of excess heat as for a specific brake setup "happy" temperature has been exceeded. There are few options to resolve the problem which would be by increase operational max temperature of your system or reduce operational temperature. Typically for our cars the first option is more doable than the second due packaging restriction we face.

Obviously all depends the tracks you go, tires, driving style, ... with R compound and experienced driver most likely will need to spend $$ on brakes.

Also very important is to know that M4 generates a lot of heat on rear brakes due DSC. If you turn off DSC dont need to worry about rear brakes but in case DSC is on even on MCM mode rear brakes will get hot.

1) going with just Girodisc / pads should help by allowing faster cooling in between braking zones but overall thermal capacity wont increase so I am not sure will resolve the problem. I never found comparative data on this. it applies to front and rear.
2) Essex recommends removing dust shield when installing their BBK. I see there is a test done by somebody in Germany on this for the front and rear. The test was done by removing dust shield on one side only and comparing with the other side. What I dont know which side left / right was removed and if the track was clockwise or counter clockwise. On clockwise track brakes on driver side work harder than passenger. According my experience is ~ 20-30F hotter.
3) if none of the above resolves than solution is to go with BBK front. The good news is you can do only front and use CCB or M2C calipers for rear with girodisc. This is the setup I have and works very well. I have a post on it.

I have done measurements by adding brake cooling with scoops under the car. My conclusion shows the flow is minimal and doesnt help because of restrictions on ducting. The only solution I didnt test was the GT4 front bumper cooling as I dont want to change my bumper. Most likely will work as it has less restriction and is located on a high pressure zone.

[Craigito]

Originally Posted by m4forum

Brake fading or pedal feeling change is a result of excess heat as for a specific brake setup "happy" temperature has been exceeded. There are few options to resolve the problem which would be by increase operational max temperature of your system or reduce operational temperature. Typically for our cars the first option is more doable than the second due packaging restriction we face.

Obviously all depends the tracks you go, tires, driving style, ... with R compound and experienced driver most likely will need to spend $$ on brakes.

Also very important is to know that M4 generates a lot of heat on rear brakes due DSC. If you turn off DSC dont need to worry about rear brakes but in case DSC is on even on MCM mode rear brakes will get hot.

1) going with just Girodisc / pads should help by allowing faster cooling in between braking zones but overall thermal capacity wont increase so I am not sure will resolve the problem. I never found comparative data on this. it applies to front and rear.
2) Essex recommends removing dust shield when installing their BBK. I see there is a test done by somebody in Germany on this for the front and rear. The test was done by removing dust shield on one side only and comparing with the other side. What I dont know which side left / right was removed and if the track was clockwise or counter clockwise. On clockwise track brakes on driver side work harder than passenger. According my experience is ~ 20-30F hotter.
3) if none of the above resolves than solution is to go with BBK front. The good news is you can do only front and use CCB or M2C calipers for rear with girodisc. This is the setup I have and works very well. I have a post on it.

I have done measurements by adding brake cooling with scoops under the car. My conclusion shows the flow is minimal and doesnt help because of restrictions on ducting. The only solution I didnt test was the GT4 front bumper cooling as I dont want to change my bumper. Most likely will work as it has less restriction and is located on a high pressure zone.

Thanks for your input. It's much appreciated. I spent almost an entire day researching this topic. Ultimately I decided to go with a AP Essex front BBK (9668). I may add a GIRODISK rear setup at some point depending on how they perform after my next event. I went with the DS3.12 Fedoro pad and will get another street pad set to run between events. I decided to do the optional Disc Pre-burnishment service.

Next track day isn't likely until October so I will provide an update after that.

I am looking for a quiet non race pad to use between events. I see so much conflicting posts on this it's hard to know what to get. Some say the DS2500 are ok then others say they are loud. I see other options from Hawk and Raybestos and others. All I know is I can't live with the noise my PFC pads have I currently use. They are ridiculously loud from 10-0 coming to a stop. Noise level is more important that performance for these pads.

[Driver407]

I debated the giro vs essex ordeal a few months ago. I also landed on essex with the the idea i would grow into them as I get faster and faster. Getting them used helped also

Also ran pfc08 on my oem setup for track days. Agree the noise is unbearable. When I switched to the essex I figured i may be able to run the 1.11 Ferodo with minimal squeal. However that was not the case. 1.11 is quieter than the pfc08 but still pretty bad.

The previous owner included a set of d2500 which i have been swapping between events. They are very acceptable. You maaaay hear a minor sound once a week. But it is not everyone staring at you loud.

With the ap racing kit. The dread of swapping pads is definitely less cause of the ease of swap. So it is a trade off.

Some people run 1.11 front bbk and 2500 on the oem rear. Some may say the brake bias is at the edge here. But i have not tried it yet. Still wearing down my last pfc08 rear.

[SYT_Shadow]

With 5 days a year, definitely girodiscs

The girodisc rotor is better than the AP one. AP redesigned theirs after plenty of people complained about bad rotor life.
To give you an example, the Turner Motorsport M4 GT4 runs the AP kit (not the one you and I can buy mind you, but more like a distant relative) and they choose to run Girodisc rotors on them.

Real BBKs have many additional problems like noise, no dust boots for snow/water/salt, etc. For 5 days a year they are absolutely not worth it

Edit: please note most places I write 'AP' in this post could be substituted for other 'big boy' race kits like PFC or Alcon-Bimmerworld. Real race kits are not meant for street use. I believe it is a mistake to run any race kit on a street car. The amount of pad clunk you get can drive sensitive people insane, regardless of running antirattle clips or not

[swagon]

Originally Posted by SYT_Shadow

With 5 days a year, definitely girodiscs

The girodisc rotor is better than the AP one. AP redesigned theirs after plenty of people complained about crap rotor life.
To give you an example, the Turner Motorsport M4 GT4 runs the AP kit (not the one you and I can buy mind you, but more like a distant relative) and they choose to run Girodisc rotors on them.

Real BBKs have many additional problems like noise, no dust boots for snow/water/salt, etc. For 5 days a year they are absolutely not worth it

Do you recommend running Giros on all four or is keeping the rears OEM with the same racing pad okay in terms of brake bias/performance on track? I do max five a year as well.

[SYT_Shadow]

Originally Posted by swagon

Do you recommend running Giros on all four or is keeping the rears OEM with the same racing pad okay in terms of brake bias/performance on track? I do max five a year as well.

Giro is better everywhere, now whether you can get away with the stock rears depends on pace. I would mount Giro front and rear because it will be a nice performance boost, or put another way, they give you more room for heat dissipation.
If Cayman GT4s with their complete lack of power run front and rear Giros, the F8X which almost runs a small nuclear reactor up front needs them as well

There is nothing wrong with the OEM calipers. Using the Giros elevates your setup to something pretty solid. Add high temp seals in the calipers and it's a different ball game

For pads I'd use the same compound front and rear, likely experimenting with a racier compound in the rear. This will move bias to the rear which you want to do anyway. In PFC it would be 11 front 13 rear assuming that exists in those fitments

[m4forum]

Originally Posted by Craigito

Thanks for your input. It's much appreciated. I spent almost an entire day researching this topic. Ultimately I decided to go with a AP Essex front BBK (9668). I may add a GIRODISK rear setup at some point depending on how they perform after my next event. I went with the DS3.12 Fedoro pad and will get another street pad set to run between events. I decided to do the optional Disc Pre-burnishment service.

Next track day isn't likely until October so I will provide an update after that.

I am looking for a quiet non race pad to use between events. I see so much conflicting posts on this it's hard to know what to get. Some say the DS2500 are ok then others say they are loud. I see other options from Hawk and Raybestos and others. All I know is I can't live with the noise my PFC pads have I currently use. They are ridiculously loud from 10-0 coming to a stop. Noise level is more important that performance for these pads.

For clarification I am not sure Girodisc with stock calipers on rear with DSC ON will help much with the excessive heat for drives which are already experiencing it.

[D_SheerDrivingPleasure]

fyi - Girodisc front rotors for OE blue brakes are out of stock. They think mid September availability.

[swagon]

Originally Posted by SYT_Shadow

Giro is better everywhere, now whether you can get away with the stock rears depends on pace. I would mount Giro front and rear because it will be a nice performance boost, or put another way, they give you more room for heat dissipation.
If Cayman GT4s with their complete lack of power run front and rear Giros, the F8X which almost runs a small nuclear reactor up front needs them as well

There is nothing wrong with the OEM calipers. Using the Giros elevates your setup to something pretty solid. Add high temp seals in the calipers and it's a different ball game

For pads I'd use the same compound front and rear, likely experimenting with a racier compound in the rear. This will move bias to the rear which you want to do anyway. In PFC it would be 11 front 13 rear assuming that exists in those fitments

Originally Posted by D_SheerDrivingPleasure

fyi - Girodisc front rotors for OE blue brakes are out of stock. They think mid September availability.

Just ordered all four Giros. My plug said fronts will arrive at his in circa two weeks.

[D_SheerDrivingPleasure]

I just ordered front girodiscs via Bimmerworld. You guys peer pressured me.

Any special torx or star sockets needed?
Also, does the caliper need to be removed for the install? This DIY video seems to show it bolted on while the rotor is swapped. Asking for a friend, of course.

[swagon]

Originally Posted by D_SheerDrivingPleasure

I just ordered front girodiscs via Bimmerworld. You guys peer pressured me.

Any special torx or star sockets needed?
Also, does the caliper need to be removed for the install? This DIY video seems to show it bolted on while the rotor is swapped. Asking for a friend, of course.

I would be surprised if the guy didn't damage the caliper paint. It's not difficult to remove the calipers on these.

[MR RIZK]

If you look at the video the caliper has been unbolted and loose to provide easier entry for the rotor. Just hasn't been removed in its entirety.

The removal shows the caliper fixed but they never show the rotor coming out. The next shot for installation shows heaps of play in the caliper.

[stevehifi]

Guys those with AP 9668 front, can you confirm that either DS1.11 or PFC08/11 still squeals on the street even with the pad tension kit? (hot or cold)

Thanks

[FaRKle!]

Originally Posted by stevehifi

Guys those with AP 9668 front, can you confirm that either DS1.11 or PFC08/11 still squeals on the street even with the pad tension kit? (hot or cold)

Thanks

The pad tension clips are described as "anti-rattle." Myself and others mistakenly interpreted this as "anti-squeal" too.

With the anti-rattle clips there's plenty of loud squeal on DS2500 and DS3.12 on the street with my 9668 kit after the pads warm up (cold there's a lot less squeal).

Without the anti-rattle clips you DEFINITELY notice the rattle and it sounds like you have something loose in the suspension. That said, the squeal is less, to the degree that I'd say it's acceptable on the street.

[stevehifi]

Originally Posted by FaRKle!

The pad tension clips are described as "anti-rattle." Myself and others mistakenly interpreted this as "anti-squeal" too.

With the anti-rattle clips there's plenty of loud squeal on DS2500 and DS3.12 on the street with my 9668 kit after the pads warm up (cold there's a lot less squeal).

Without the anti-rattle clips you DEFINITELY notice the rattle and it sounds like you have something loose in the suspension. That said, the squeal is less, to the degree that I'd say it's acceptable on the street.

Thanks, aside from DS2500 do you happen to know any other manufacturer that makes a 'sport' style pad for this caliper (with low noise)?

[FaRKle!]

Originally Posted by stevehifi

Thanks, aside from DS2500 do you happen to know any other manufacturer that makes a 'sport' style pad for this caliper (with low noise)?

Essex has this page with other pads that should fit (or with some small modification). Looks like there's some EBC red/yellow and Hawk HPS in there.

[SYT_Shadow]

Originally Posted by stevehifi

Guys those with AP 9668 front, can you confirm that either DS1.11 or PFC08/11 still squeals on the street even with the pad tension kit? (hot or cold)

Thanks

I run PFC11 all the time on my BBKs. It has the lowest noise of any track pad, most of the time it is completely quiet

08 is a louder compound, as is 12

[stevehifi]

Originally Posted by SYT_Shadow

I run PFC11 all the time on my BBKs. It has the lowest noise of any track pad, most of the time it is completely quiet

08 is a louder compound, as is 12

Thanks for the feedback. I ordered Schirmer's brake kit. He uses PFC05 front and PFC 332 rear. He says with the anti rattle brackets it should be relatively quiet for street. For the track he says to switch to PFC11 in the front only.

Hopefully it's not too bad on the street, I don't mind mild or soft squealing noise but not loud high pitched screeching at low speed (15mph-0) like the DS1.11s I had on stock calipers.

[SYT_Shadow]

Originally Posted by stevehifi

Thanks for the feedback. I ordered Schirmer's brake kit. He uses PFC05 front and PFC 332 rear. He says with the anti rattle brackets it should be relatively quiet for street. For the track he says to switch to PFC11 in the front only.

Hopefully it's not too bad on the street, I don't mind mild or soft squealing noise but not loud high pitched screeching at low speed (15mph-0) like the DS1.11s I had on stock calipers.

The 332/331 pads are what all the cool kids are running, but they are louder than the 11
Right now one car is on 11/11 and the other is 332/331. I never confuse which car I'm in haha

[Daytona_550]

Originally Posted by SYT_Shadow

With 5 days a year, definitely girodiscs

The girodisc rotor is better than the AP one. AP redesigned theirs after plenty of people complained about bad rotor life.
To give you an example, the Turner Motorsport M4 GT4 runs the AP kit (not the one you and I can buy mind you, but more like a distant relative) and they choose to run Girodisc rotors on them.
…

I'm debating between using J-hook rotors vs. Girodisc rotors (on a CP9660 kit). Can you share why you feel the Giro is better? Longevity, brake efficiency? Much appreciated!